University Place

Growing Citrus Trees in Wisconsin

– Hello, everyone. Welcome to our presentation today, where we’re going to be learning all about growing citrus trees in containers. My name is Frank Lazar. I and my wife, business partner Taylor, we are co-owners of Frank’s Fruit Trees, the only citrus tree nursery in Wisconsin. I’m also a graduate student at the University of Wisconsin-Madison, where I study plant breeding and genetics. – Hi, everyone. As Frank said, I am Taylor Lazar. We are both co-owners of Frank’s Fruit Trees and I am also a graduate student at UW-Madison. I’ll be graduating this May with my master’s degree in social work. I did not start out as a plant expert, but I now know way more about citrus trees than I ever thought that I would. Welcome to “Growing Citrus Trees in Wisconsin.” I wanna point out here that, yes, we are talking about living in Wisconsin, but this information is gonna be applicable to growing citrus trees anywheres indoors. All right. So I wanted to go through a little bit about just a run-through of our presentation today so you can keep track of where we’re at. We’re gonna start just talking a little bit about our story and how we came to be business owners of Frank’s Fruit Trees. We’re gonna go into some general information about citrus and how to care for them. And then we’re gonna go more detailed into some things like pH, temperature, grow lights, soil, fertilizer, containers, pests, and then we are going to get into the PANICS. This is where you laugh. [chuckles] [audience laughs]

So to begin, we wanted to tell you a little bit about us. And our story begins about six years ago in Frank’s college dorm room. This is the first citrus tree that Frank has ever owned. [audience laughs] He grew it in his dorm room in college, and he might not’ve been the only college student with a purple light emanating from his room, but I’d be willing to bet he was the only one growing a citrus tree. [audience laughs] Frank learned a lot about caring for citrus trees and eventually, his collection expanded, and it took over our coat closet in our apartment. After a few years of owning what was likely the largest collection of citrus trees in the state, we noticed that not many people knew that they could grow an orange tree in their dorm room. Now we are both owners of Frank’s Fruit Trees, and Frank manages our in-home greenhouse of hundreds of trees, and I manage the business side of things. We’ve been in business for almost a year now and we are loving it. We’ve also developed a lot of techniques and tips that have helped us to be successful at running the only citrus tree nursery in Wisconsin, and we’re going to share those with you today.

– We’re gonna start off today’s educational portion by giving you a little history and some general knowledge on citrus in general. So it’s really crazy to think that all the citrus that we know today, right around 200 different varieties and flavors, originated from basically five simple trees. So the main five citrus, basically, slowly intermingled and crossed with each other through trade, natural selection, and they yielded all that we know of today. Mandarins, over to the far right, gave us our sweet oranges and also the mandarins that we know today as well. The pomelos are what we know as grapefruits. Pomelos are still around. All of these ancestral species you can still find today as well. Some of them actually in cultivation, too. The citrons gave us our lemons. The small flowered pepitas are to the limes, and kumquats are still our kumquats. I wanted to talk a little bit about planting citrus seeds, as many of you also have asked me questions about that or have a seed-grown tree, and this is a very easy and very fun thing to do, especially for those that may not have the greenest of thumbs. It’s a very great starting point. A very cheap solution to learn how to do this before investing into something, ’cause citrus trees can run quite expensive.

So this is exactly how I started. I basically in my undergrad went to the supermarket every other day and, basically, found any and all fruit that I could find, dig out the seeds, toss the fruit away, and see if it would grow. [audience laughs] The major downfall of this method, though, is that seed-grown trees typically take anywhere from the 8 to 30 years to produce, and that is in their natural environment. So being restricted in a container, may be a lot more. But it all depends on the care that you give it, of course. Not only this but often, as with most fruit trees grown from seed, the fruit quality may come out to be unpredictable. May be undesirable. May be a little more seedy, sour, thorny plants, something of that nature. There are very few varieties that actually produce 100% true to their parent that you took from the fruit. And this is why exactly there are specific methods to clone trees to produce the desirable fruit that we all like today.

When you buy a citrus tree, you’re likely either to get a grafted or a rooted tree. Grafting, or the method on the left is, basically, a process by which most fruit trees are commercially produced. Essentially, grafting is a process of combining two compatible trees together to form one super tree, almost. The bottom portion, known as the rootstock, is selected for specific traits that, basically, enhance environmental tolerances and make it more suitable for different climates. So these are things such as root rot tolerance, especially in containers. This is a big one that really helps that out. Cold hardiness, disease resistances, and they also do a very big number on size and growth restriction. Rootstocks can have, like I said, a significant impact on limiting the size of your tree, and for container trees specifically, we recommend using a dwarfing rootstock or trying to find something with that. A grafted tree also, just a couple features, will have more of, like, your upright, tree-like, topiary-look structure at maturity. They’ll typically yield a larger tree.

Rooted cuttings or the other method that’s shown on the right is another method. This is actually called marcotting. Not sure if many of you are familiar with that, but this process is done right on the tree. It helps essentially keep that scion or the budwood fresh and ready and able to produce roots a lot quicker. So this type of tree is essentially on its own roots, the same as that of the parent tree, but the downfall of this will be that it is more susceptible to its environment stressors, so basically, than that of its grafted counterpart. They’re a little more difficult to care for. But that is okay, though, because they’re container-bound trees in this instance. So the environment is controlled by you, the grower. So you choose what it can and cannot be exposed to. You’re in control of that aspect. Rooted cuttings are typically a smaller tree at maturity than that of its grafted counterpart and give a more bushier look to it. Perfect for smaller windows and, say, apartment complexes. The one last thing I wanted to touch on why citrus make amazing container plants is that citrus are very adaptive to their environment, within reason. Citruses are severely limited by their environment. So I like to use an analogy like a goldfish. Basically, if you wanna really big goldfish, you’re gonna put that into a really big tank. It’s gonna grow to that size of that tank and, realistically, kinda cap-off from there. If you wanna keep your fish small, you keep it in a small tank. The same thing with the containers. However, there are a few restrictions on that, mostly due to fruit size of the variety. You may want a larger tree, such as in the example of a grapefruit. Obviously a grapefruit in a small one-gallon container will not produce very much, because that massive fruit requires a lot of structure and a lot of energy to be produced. Versus a kumquat in that same one-gallon container, those fruits are about the size of maybe a quarter to a 50-cent piece size. They’ll be able to be rather productive in that same little container.

– So as Frank just got done saying, citrus trees know how to adapt very well to their environment, but there are limits to that. For example, I think most of us know that we can’t walk outside in Wisconsin and plant a citrus tree in the ground and expect it to survive due to the harsh temperatures that we have, what, 12 months out of the year? [all laugh] Most citrus trees can handle down to about freezing, 32 degrees, with some exceptions. But those low temperatures are not very conducive to encouraging growth or fruit production. On the other hand, citrus trees don’t need tropical temperatures, although they can withstand pretty high temperatures. They’ll just need a few more drinks throughout the day. A little less sunlight. But in order to encourage growth, they need to be above about 60 degrees most of the time. We recommend leaving your tree outside during the summer, as there are a lot of benefits to doing so, which we’ll get into. It can stay outside until temperatures get down to about 40 degrees consistently at night, at which point it needs to come inside for the winter. Since it’ll likely be going from all-day sun outside to limited sun from a window or a grow light, it will also be important to transition it slowly. Leaving it in the shade outside for a week or two before bringing it in will help it to feel a little bit more comfortable with the light reduction.

When you put your citrus trees in the window during the winter to get sun, you’ll need to pay attention to the temperature around the window as well. If the window is drafty or it gets below that 60-degree mark, that’s when you’ll wanna put in some extra effort to keep the tree warm. This can be done with something as simple as a heating mat, which we’ll also talk about a little bit later. One mistake that you do not want to make is putting your tree next to a heater or a vent. This can provide warmth, but it will dry the tree out.

Since citrus trees are subtropical plants, they like a decent amount of humidity. The good news is that most of our homes are already at the perfect humidity for them, at about 50% to 70% humidity. If you notice that your house gets a little bit dry, especially in the wintertime, we recommend using a humidifier or placing a pebble tray under the tree to put a little bit of moisture in the air. Pebble trays are pretty easy. Just put some water and a few pebbles into a different tray and put the pot on top of it. You’ll just wanna make sure that the pot does not sit in any water. This will also give you a nice aesthetic if that matches your room. And on the topic of watering, one of the most frequent questions we get is “How often should I water my tree?” Unfortunately, we are not able to give one general answer because the amount of water that your tree needs will depend on a lot of things, and for that reason, cannot say it enough, do not calendar water. The type of soil, the temperature, the amount of light the tree gets, lots of things will determine how quickly that the water is absorbed in the pot. And this is why on hot days, your tree might need watered twice a day, but then in the wintertime, it might only need watered once a week. The best way to know if your tree needs watered is by feeling the soil. You should let the soil dry out completely in between watering. Treat it kind of like a cactus. Another way to know if your tree needs watered is to pick it up and feel the weight of the pot. When you water the tree, it’ll be fairly heavy since the soil’s drenched, and then when it needs to be watered, it will feel significantly lighter. You can also use a moisture meter if you’re really worried about it. Wait until the meter gets down to about a one before you water it again. The most important thing to know about watering is that citrus trees hate wet feet. When you water the tree, water it like you would any other house plant. Let the water run out of the bottom and then do not let it sit in any water afterwards. Wet feet can cause root rot, which is one of the most common killers of citrus, and this is why it’ll be very important to empty the tray if you’re using one. Some trees are more tolerant to wet feet than others. One factor that can determine that is whether the tree is rooted or grafted. As Frank mentioned, grafted trees have rootstock that is specifically selected for environmental tolerance, so they’re typically a little bit more forgiving when it comes to overwatering.

One thing citrus trees are not as forgiving about is sunlight. Light requirements vary based on the variety, but in general, most citrus trees need about six to eight hours of direct sunlight every day. A good rule of thumb is that the bigger the fruit, the more sunlight the tree is going to need. For example, it takes a lot of energy to produce a huge grapefruit. So grapefruit trees need a bare minimum of six hours of sunlight every day, but eight or more hours, ideally. On the contrary, kumquats are only about the size of a quarter, so they only need about three to four hours of direct sun. As I’ve mentioned, citrus trees are subtropical. So they’re very light-demanding and they need that direct sun in order to thrive and produce. The upside of that is that they really can’t get too much sun. They actually don’t technically need a night cycle. They would take sun 24 hours a day if they could. So just be sure that they’re watered enough and don’t overheat, and they’re pretty content.

– All right, now that you know a few of the basics, it’s about time to dive into a lot of the deeper areas of citrus care. I really wanna first note that we’re about to run through a lot of information here and a lot of possible issues. But please do know that most of our customers are very happily growing as they are, and we’re going to go through this, essentially, because we came here to prepare you for just about anything that could happen with this. So that way, if you ever do run into any of these issues, you know how to resolve them very quickly. The first thing that we’re going to talk about today is the pH levels of your water and soil. So citrus really like a pH of around six and a half. This is essentially where all of the nutrients required for their daily function is readily available. And by that, I mean that there are certain minerals, especially the micronutrient end, that become locked up or unavailable at different pHs due to their chemical properties. Citrus can typically tolerate anywhere from five and a half to seven and a half pH. However, as this graph shows, as you approach the higher end of seven and a half or lower than five and a half, you may run into a few potential issues at nutrient availability, and they will become locked up. This essentially means that no matter how much fertilizer that you throw at your tree, they will not be able to access that due to those nutrient chemical properties. Specifically, you can see the iron, zinc, copper, and manganese become very slim as you kinda get towards that higher or alkaline pH. The black line here, right at the six and a half, you can see also that all nutrients are perfectly accessible to the plant. So all of that is to say, again, if you’re fertilizing appropriately and according to instructions and still see nutrient deficiencies on your leaves, you may be wanting to check the pH of the water that you’re giving it.

Here’s an example of an iron deficiency. Typically your first sign of a high pH environment, especially here in Wisconsin, as a lot of our ground water is very rich in iron, so that supplements very well. Iron deficiency typically shows as following, which is the interveinal chlorosis, that yellowing in between the dark green veins up here. Again, like I said, if you’re seeing this, it’s typically a pH issue, overfertilizing. So now that you, or now that we’ve talked about this potential issue, I’m going to give you a couple pointers on how you might be able to fix it or prevent it. Here at Frank’s Fruit Trees, we take simple steps essentially to adjust the water. And my first recommendation is to head over to your local garden store and pick up yourself a pH pen, something simple. They’re relatively cheap. Calibrate it according to instructions and test the beginning water. If you’re like us in the Madison area, our water typically sits, at least at our place, right around seven and a half to eight and a half. Very, very alkaline. Very high, which certainly needs to be adjusted. And essentially, the way that we bring that pH down, we personally use a pH down liquid that you can find at a lot of hydroponic stores. However, some household things can also be used, such as vinegar and lemon juice. I’ve used both of those in the past with very good success. It’s very, very important, however, to add in small increments and test it very often. You don’t wanna just plug a half a cup of lemon juice into a gallon of water and pour it all over your plant. What I recommend is first filling up a gallon of water, take an eyedropper, essentially, and do a couple drops of liquid, shake it up, test it with that pH pen, and slowly adjust from there. Bring it down to that six to seven pH range and you’re about golden.

If you’re the outlier that actually has acidic water below the pH of around five and a half, you may want to consider bringing that up to prevent any long-term damage to your tree. The solution that I usually recommend to that is, potentially, maybe an aquarium pH up. Those usually work very well, so then you don’t have to get into those weird chemicals and house those around. If you don’t really like either of those answers, maybe consider doing something like deionized water. Although it may not be in that six and a half pH range, it will lack a lot of those nutrients and minerals that may heavily influence that within a container. One way really to avoid worrying at all about the pH of your water is to use rainwater. Rainwater is, by far, the best thing that you can do for your tree. I notice it’s so much more helpful for our trees when we throw ’em outside. They just look so much happier when they get strictly rainwater. Not only is it packed with a lot of those essential micronutrients that your tree might need, but it also has a natural pH of around five and a half to 5. 8. So if you’re able to throw your tree outside, your tree will severely thank you for the summer.

– So as I’ve mentioned earlier, temperature is an important factor to pay attention to when it comes to your tree in the wintertime. Cold roots or cold feet usually lead to wet feet, which, again, can cause root rot. The amount of light that your tree gets will affect its temperature. So if your tree is getting adequate lighting during the winter, temperature should be less of a concern. However, it can be pretty difficult to replicate the hot summer sun inside a Midwestern home during the winter, especially at night. If you notice that the bottom of the pot is cold to the touch, your tree has cold feet. In this case, we highly recommend purchasing a heating mat or a germination mat to put under the tree. You’ll wanna be careful not to run it all the time, as that can actually burn the roots. But you can run it overnight to keep the tree warm during the coldest times. There are a lot of ways to set up a schedule like this, with the most common being an outlet timer. These can be purchased almost anywhere for relatively cheaply, and they can be set to run the heating mat overnight only. A lot of people also have smart homes now, where they can control outlets and light switches with their phone, and, typically, there are scheduling options available with those systems as well. Lastly, if your brain works better than mine, you can remember to plug the mat in and unplug it each day. I don’t recommend it, but if you’re good at remembering things, then you might be able to swing it.

– All right, as Taylor said, it can be very difficult to replicate the sun in the wintertime, especially. But the big question is do you need a grow light, or will the sunlight be enough that you currently have? This is something, again, that we get a lot of questions on, and it’s very important to know that not everybody does actually need a grow light. But it’s very important also to know that every tree definitely needs light. So knowing those needs and your specific variety and basically the tree’s needs and making sure that they’re fulfilled is the important thing. Typically, with those that have less than six hours of full, direct light can definitely benefit from supplementation with a grow light, that is. Citrus are very hungry plants, so they do need to drive a lot of photosynthesis. First thing, again, it’s very important to know that not all grow lights do the same thing. Different lights have vastly different values, different outputs, photosynthetic spectrums, as well as quality between lights. First, there’s a few terms that I would like to clarify first, because a lot of the grow lights are really determined by these, like, basically how good a grow light is. They use these PAR and PPFD values to determine that. PAR, or PPFD rather, stands for photosynthetic photon flux density and PAR stands for parabolic aluminized reflector. These terms are often used, again like I said, to describe basically light outputs within the photosynthetic spectrum. Personally, I like to follow PPFD values, as that’s a little more of an accurate representation of light that can actually be used for photosynthesis. Our first image here is of a generic grow bulb. Typically, on average, they put out maybe 8 to 30 PPFD, and that’s a pretty generous estimate for most. This is really still a fantastic light, especially if you’re just using them to supplement an already mostly sunny exposure and get that little bit of extra for your tree. Our second or middle image here is our LED grow light. Personally, I use these a lot. Our winter exposure is very slim on light, so I typically grow only under LEDs and our trees do very well. They’re typically labeled as a 1,000 watt. However, due to efficiency reasons, they usually consume around 100 at the wall. And, again like I said, they’re pretty much all I use. Typically, they output anywhere from around 500 to 1,000 PPFD, which is right on the sweet spot for most citrus. For example, citrus mostly need around that 300 to 500 range, from what I’ve seen. To stimulate vegetative growth and to sustain fruit and full production, right around the 800 to 1,000 PPFD.

Our last image here on the far end is of comparison to full sun. So that’s anywhere from 1,200 to 2,000 PPFD. So as you can see, it’s pretty hard to replicate that full, direct sun exposure, even with really good quality LEDs. We can only essentially do our best to mimic it. Another question that we get asked is how long should I run my grow light if I have one? And as always, my favorite answer is, it depends. So it will depend on a multitude of factors, such as your light’s power, how much sunlight your tree naturally gets, the light hang height, and so much more. We typically say that if you’re in that two to four hour range and have a 1,000 watt LED, typically 16 inches above the tallest leaf, ran for a supplemental four to six hours a day should suffice, and you can always increase that as your tree needs. If you’re like us, like I said, and grow strictly under grow lights in the winter, we run ours at 16 to 24 inches above the tallest leaf and run them for 14 to 16 hours a day.

– Another factor that you’ll want to consider when it comes to caring for your tree is the type of soil that it is planted in. A lot of people think that potting mix is universally great for any and all plants, but that is not true for citrus trees. Potting mix is very dense and very good at holding onto water, which, we all now know, is terrible for citrus trees. Almost every instance we have seen of root rot has occurred because the tree was in dense soil. For this reason, we recommend a soilless mix or a very airy soil. Now, we have a lot of experience with citrus trees, and over several years of trying different brands of soil, we decided that none of them worked well enough for us. As a result, we make our own soilless mix. We use a 2:1:1 ratio of coconut chips, coconut coir, and perlite. This helps the tree to retain only the water it needs and let the rest drain out. Soilless mix also lasts up to about 10 years, so it very rarely has to be replaced, unlike potting mix. Now, we do realize that not everyone wants to purchase materials like this in bulk for a tree in a two-gallon container. So if that’s a concern of yours, you can also just purchase some perlite to amend your soil. If you choose to do this, you should have about a 2:1 ratio of soil to perlite.

– All right, so it’s very important to select a very well-balanced fertilizer when it comes to citrus, something that ideally contains everything that your plant needs to thrive. Our presentation is specifically tailored towards container plants. So by that definition, you the grower are the one that needs to feed the plant, as it really can’t reach out past that container to get to those nutrients it might need. And without input, you definitely will not get output. So citrus are very heavy feeders, so they require a lot of nitrogen to sustain their daily functions. We recommend using a fertilizer that contains at least a 2:1:1 ratio of the main three, NPK, and that is also known as the macronutrients. So an example of that might be like a 14-7-7. That’s something that you might find at the local garden store. These are nutrients, essentially, that are used in very large quantities by plants in general aspects.

It’s also just as important to ensure that your fertilizer contains micronutrients. This list up here shown on the screen is what is vital for your citrus tree’s growth and especially flowering. It’s very important to, again, as I said before, follow the instructions on the container, as every fertilizer is a little bit different from another. The manufacturer will essentially suggest what will be appropriate, so that you don’t accidentally overfertilize. Micronutrients are used in such small quantities that high concentrations can definitely cause some severe damage if overused. I also wanted to touch a little bit on organics, because I know this is a very big rising area, and it is very much okay to use organics in containers. However, there might need to be a few additions to that. Many organics require microbial activity in order to break down into more plant usable form. So there are some that are already in that usable form, but for the most part, what I see, organics are not. So if you’re wanting to use an organic fertilizer, I would recommend supplementing that container, which usually lacks a lot of microbiota because it’s very confined, there’s not a lot of exchange going on there.

Supplement that and add some essentially mycorrhizal fungi or different beneficial microbes that will help that breakdown process. So into a couple of the common deficiencies that you might see as growing citrus trees. Remember that I said that citrus need a lot of nitrogen to sustain themselves, and here are a few signs of nitrogen deficiency on citrus leaves. You’ll start to notice the yellowing or chlorosis, typically, in the lower set of the leaves, the older growth as well as they’ll start on the outside or the rim of the leaf and slowly work its way in, while that chlorosis, or the yellowing, will eventually turn to necrosis as in dead tissue. Once your leaf shows symptoms, it’s very important to know that it will never correct itself in the old growth. It will only be shown as new. So be looking to that. Don’t look at the old growth once it starts and be sure not to overfertilize, thinking that it needs more. The next slide, again, as I’ve shown before, another iron deficiency. However, as I said before, here in Wisconsin, we’re very high in iron, so this might likely be more of a high pH issue than fertilizer. It’s very important to stress again that if you’re fertilizing correctly and still see these symptoms, check the water of your pH, check the soil pH, and go from there.

– Another common question that we get a lot is “What type of pot should I plant my tree in?” The main two choices on the market are plastic and terra-cotta. We typically recommend plastic pots for citrus trees for a few reasons. Plastic will help keep the tree warmer, especially during the winter. Terra-cotta also tends to hold onto water a little more, especially in colder temperatures. If you like the aesthetic of a terra-cotta pot and really want to use one, we recommend putting the tree in a plastic pot and then putting the plastic pot inside the terra-cotta. We also want to make sure that water can drain freely from the pot so that we prevent root rot. It’s extremely important to make sure that whatever container you use has drainage holes. And, again if you use a tray, make sure you empty it a few minutes after watering so that the tree is not sitting in any water.

A common mistake that we see a lot with citrus trees is planting them up too quickly. Citrus trees are very different from most plants in that they actually like to be root-bound. When citrus trees are root-bound, that signals to them that they have no more room to grow and then they start focusing on fruit production. Your focus with planting up your tree should be to slowly and incrementally move up in container size until you get to the desired tree size. Once you start to see roots poking out of the bottom of the pot, that’s a sign that your tree could use a new home. However, there’s a few things to consider with that. As I just said, when citrus trees are root-bound, that signals to them that they have no more room to grow and they start focusing on fruit production. They’ll stop growing and start pushing out fruit. Now generally, the larger your tree, the more it will produce for you. It’ll be up to you to find the balance of how large a tree you want in your home versus how much fruit you want it to produce. If you’re wanting more growth from your tree, wait until you see those roots poking out of the bottom of the pot and then move the tree up into a slightly larger container. We don’t recommend moving up more than one or two gallons at a time. So if your tree is in a one-gallon container, it shouldn’t go into anything bigger than a three-gallon container. If the tree gets put into too large of a container, there will be way too much soil for the amount of roots that the tree has, and this will cause the soil to retain water because the tree doesn’t have enough roots to soak it up. Moving up container sizes in steps incrementally will help to avoid this. Once your tree is at the size that you want it to stay, don’t move it up into any larger of a container. It’ll become root-bound and it’ll focus on producing the fruit that you’re working so hard for.

– All right, so this is a very important topic, especially if you have house plants. Pests are likely inevitable. Unfortunately, citrus are very similar to that of a tomato, where they’re essentially a magnet. Pests will seek them out if they’re around. Therefore, if you have trees outside for the summer, it’s very important also to stress to screen them for pests prior to them coming inside. This is the final portion of our seminar here, and we’re going to detail the three main pests that I typically have noticed and how to control them. So first on our list today are the aphids, and I’m sure many of you are very familiar with what an aphid is, as they’re also a common garden pest. The first sign of an aphid, or scales for that matter, which will be detailed next, is sooty mold and honeydew. Essentially, the sooty mold is a substance on the leaf. It’ll look almost like an ash that won’t wipe away. This is actually a fungus that’s attaching itself to the plant to feed onto that honeydew, which is the aphids’ excrement. Honeydew is essentially a very highly concentrated sugar-sap mixture that the aphid is unable to process fully. So it comes out mostly as sugar, which the fungal microbes attaches to and basically eat. Aphids are creatures that can reproduce asexually as well. So it’s very important to control them quickly before populations can accumulate. Their life cycle lasts anywhere from 8 to 27 days. So as with any pest, persistence is really key to control. The best control method, in our opinion, is pressured water. Blasting them off far away from your tree, maybe over in your neighbor’s yard will prevent them from getting back to yours and feeding on your tree. However, if you do still see them come back or you can’t quite get them all, a great organic pesticide that I found works very well on them called pyrethrum. It’s a naturally occurring substance that’s found in chrysanthemum. However, it is very toxic to bees. So be sure when you’re spraying, if you decide to go that route, that it’s very contained, that you’re not going around anything that’s flowering. That your tree’s not flowering. And the other thing also, if you want to stay USDA-certified organic or you want to stay organic, a lot of times pyrethrum is mixed with other synthetic things to make it more effective. So just be sure as with any pesticide, herbicide that you might use, read the labels and follow the directions.

So scale, the next on our pest list I’d like to touch on is a little less common in Wisconsin; however, equally as gross as aphids. [audience chuckles] They can sometimes be transmitted from other woody house plants, such as anything that you might take home from a nursery, from different stores, or even from different neighboring fruit trees. Typically, soft scale is the most common, which is good, as they are soft bodies and respond really well to pesticides. Scales are a little harder to treat, as sometimes they’re harder to notice. As you can see, they kinda have that same bark color to them. They plate up and almost look exactly like the bark on the tree. The first sign though, again, will be that sooty mold and honeydew, just like that of the aphids because they’re actually very much related to an aphid. They can also reproduce sexually for that matter. So the way that scale infect is, basically, the female will plant itself in a spot on the tree that it thinks is nice, burrow itself in, and basically attach itself to it, and it’s almost like concrete. It won’t come off unless you put a fair amount of pressure to either scrape it off mechanically or when it’s gone, they typically blow off with the wind.

Young scale, known as the crawlers, do exactly what they’re named after. They crawl around the tree, essentially trying to find a good place to set up camp. Scales again, like I said, they’re a little harder to treat because the water method typically does not work as well with them, as the females really cling to the bark. They don’t wanna let go for anything. So although to treat, I would also still recommend blasting off with water, getting all those crawlers gone, all the juvenile scale that will be walking around on your plant and then from there, you really have two options. The first one is to go through the grueling process, as I’m sure many of you maybe have heard, wiping the tree from top to bottom, under, over every leaf with the cloth and rubbing alcohol. If you have some pretty big trees, it’s gonna take a while, and like I said before, persistence is key to control. The life cycle, basically if you stop at day seven, day eight, more hatchlings will come out and then you’re starting all over again. But otherwise, that same pyrethrum I have found to be very, very effective towards scale.

The last on our list here is the two-spotted spider mite. And I’m sure again, many of you are very familiar with this, as this tends to be the most common house plant pest known to date, in my opinion. You’ll see those little cobwebs, which I assure you is not a friendly, beneficial spider coming to help your plants. Again, many of you I’m sure have had problems with spider mites in house plants, as they typically come on a lot of nursery stock. They hitchhike on just about anything to get in. From the neighboring grasses, they blow through the wind. Somehow find a way to your tree, especially when they’re outside. The worst thing about this pest is that it has a really crazy life cycle of anywhere from 8 to 40 days. So again with aphids, more importantly spider mites, persistence is your best friend. Many recommend horticultural oils and soaps; however, they may work at first. In my opinion, does not ever really get the full job done. Horticultural oils should not be sprayed too often, as would needed to be controlled of spider mites. For this reason, they tend to block air exchanges and photosynthetic areas of already really waxy citrus leaves. So a lot of issues can arise with that. Like, I have had a lot of defoliation just from a simple neem oil spray, something like that. So I tend not to like it as much. Of course, I’m not one that wipes off the oil as you should after you spray, but that’s a different thing. [all laugh] So water, in my opinion, is by far the best control method for spider mites. A cold jet of high-pressured water over and under every leaf every day for a couple of weeks will pretty much take care of any population that I’ve ever seen.

These pests usually don’t show themselves ’til wintertime. You know, so once it gets cold, that’s when pretty much all those little webby things come out and after you bring it in and it’s harbored from the Mother Nature’s sort of control, putting it in the shower, washing it off every couple of days will also work. Again as I mentioned before, I’m very persistent with this, but persistence is key to control. Otherwise you stop on that final day, that life cycle’s gonna start all over again and you’re just gonna be back at day one. So here at Frank’s Fruit Trees, we only use organic methods of control and only when needed. So to recap, water blasting is the first resort that will take care of most pests, even some that I haven’t mentioned here, such as mealybugs. Only use horticultural oils and soaps when necessary, as well as pesticides. They have a very large impact on the environment around it. So it’s important to be conscious of that when using them. This might be the case if you have a scale issue, as well as I feel that many times pesticides or biologicals might even be a safer, better bet for your tree in the long run.

Finally, one point I would also like to make is that Mother Nature does a really good job of keeping pests in check when outdoors. Ladybugs, wasps, different predatory mites, the wind, the rain, do a very good job at basically keeping your tree clean. It’s very, very important for this reason, again, that prior to bringing them inside, your tree should be screened for pests and treated appropriately. Because as soon as you bring them back inside, you’re basically putting a little dome around your tree from Mother Nature from helping you. Any of those are free to basically breed and colonize your tree. So this is basically the main points of when you have pest issues arise.

– Okay, we just went through a ton of information all about the dos and don’ts for growing a citrus tree, and I know it’s a lot, and that’s why for some of you, you’re wondering how you could ever remember all of this. And now it is time for the PANICS. [audience laughs] So we came up with this fun little acronym to help you all remember all of the important pieces of citrus tree care. If you notice something is off with your tree, I can almost guarantee it is due to one of these things. Make sure you’re addressing all of these areas of care and you will likely find the culprit causing your tree’s distress. Be sure to have a pH between five and a half and seven and a half so that your tree can absorb all the nutrients that it needs. Give it an airy soil or a soilless mix so that water drains well. Use a fertilizer with about a 2:1:1 ratio of NPK, plus micronutrients. Only expose the tree to temperatures that you’re also comfortable living at. Watch your watering, only give it water when the soil is completely dry, and make sure you’re giving your tree adequate sunlight. If you have all the PANICS, you’ll become a citrus tree guru, like Frank here. [audience laughs]

If you are interested in purchasing a citrus tree or any of the supplies that we mentioned today, feel free to check us out. We are located in Sun Prairie, Wisconsin and everything is located on our website at franksfruittrees.com.
We have lemons, limes, oranges, kumquats. I think we’ll have some grapefruits over the summer. And we also sell our handmade soilless mix that I was telling you about, as well as the grow lights, fertilizer, and heating mats that we use ourselves. Every tree comes with a free citrus tree care guide. So if this was too long to sit and listen to a lecture, don’t worry. We have everything written down for you. We also encourage our customers to reach out to us at events on Facebook, give us a call, send us a text or an email if you have any questions before or after your purchase. We are happy to help diagnose any issues that you might have or offer advice or give recommendations. Check us out. And lastly, don’t wait for life to give you lemons. Grow your own. [audience laughs] Thank you. [audience applauds] If anybody has any questions, we have a few minutes left to be able to answer some of those. Oh, in the back there.

– So the question was that he has some honeydew-like substance on the leaves around this time of the year, but no sign of pests and a source for citron trees. Citron, I’m actually working on propagating quite a few different citrons like variegated citrons and what’s called an etrog. So hopefully, in the near future, I will have a couple of those available. As for the honeydew, sometimes citrus do excrete something or some sap from their leaves that may resemble honeydew, and that might be due to some sort of environmental stress that comes with the adjustment period of bringing an indoor outdoor. However, I would definitely encourage you to look a little bit closer to those. A lot of times, there are some insects that are almost microscopic. You know, you could barely see them, that might be producing that.

Okay, so basically the question was if she purchased a tree this year, will it fruit? How long will it take to fruit and how often will it fruit? So that really depends on the maturity of the tree that you would want to purchase, as well as if it’s rooted or grafted. So typically, our rooted cuttings, we say anywhere from 3 to 12 months, depending on the variety, you should see flowers, and then thereafter, a season or two should produce some sort of fruit. Now the ripening times on those very much vary, and then that kinda goes into the next question with how often does it fruit? Most citrus trees in Florida or California, any tropical environment, have specific seasons. However, there are so many different stressors and different regulations here on those trees that they don’t really know what season is what and they tend to fruit anywhere from, or push flowers, anywhere from two to five times a year. So many of them are very prolific, especially like Meyer lemons. Once they start, they never seem to stop. Kumquats are like the same. Grapefruits and oranges may have one or two flowerings a year. I’ve seen up to three or four.
You know, it all really depends on kind of the environment that it might be exposed to.

– Audience Member: I think it’s dead, but I don’t know for sure. [all laugh]

– So is it common for citrus to lose their leaves over the winter? Meyers specifically, I would say that’s a very common thing. However, it’s not necessarily normal for it to do that. Meyers are one of those very finicky, picky varieties. They’re labeled as one of the most common house plant citruses that are sold to date. And I’m not really sure why, because they are one of the most difficult ones that I’ve ever had in my life. I’ve probably killed more Meyers than anything else. [audience laughs] However, the thing that I have really realized about Meyers is that they really don’t like environmental change, like that. [snaps fingers] So weaning them out and in. Say if you’re doing really well in the summer, they’re soaking up a lot of light and you wanna move them indoors for the winter, slowly weaning those off onto a lower light condition will certainly help that. Another thing with Meyers is, most importantly, the soil. As Taylor mentioned, a lot of Meyers especially are prone to root rot, and, again, they’re just very fussy plants. So trying to keep all of those in check at the same time might be the harder balance for it. Yeah, but it may not be dead. I wouldn’t give up on it. If it has some green growth, one good thing to do, sorry, tune back into that. Kind of try to make, like, a microclimate for it. What I always do is grab like a bag, a nice clear plastic bag, put it over top, kinda wrap it with some string and make almost like a little greenhouse for it. That’ll provide a lot of high humidity, as well as the germination mat, which may help the roots become more active and just push out that top full growth a lot quicker.

[audience member speaking faintly] Yeah, I mean that works as well. I like the greenhouse little effect more because it keeps it a lot warmer inside that little area and overall, that might just be a little bit better for the plant in recovery. I see a question.

– Audience Member: What would you recommend for someone to start off with?

– Starting off with? My favorite one to recommend is the Calamansi or Calamondin Orange, which is actually a kumquat. So kumquats are really, relatively easier to take care of, as well as the variegated pink lemon. That’s one of the varieties that we offer often that is pretty hardy. They require a little bit less sunlight. They’re a little more forgiving, especially the Calamondin. Those things are just awesome. They bloom profusely. Very prolific and provide a lot of harvest and are very resistant to root rot.

– Audience Member: Thoughts on what might be causing that?

– Okay, that might just be a simple environmental stress. Like I said before, Meyers are very picky. Also, Meyers produce a lot of flowers. I think I’ve seen something before where most citrus only keep about 5% of their flowers, if that, especially for their first couple of produces. But you said that it has produced many times in the past?

– Audience Member: Yeah, it has for 15 years.

– Okay, I would think that maybe checking the fertilizer balance that you might have. Like I said, a lot of the micronutrient values are very important for flower development and flower setting. So right as soon as I see those little buds, I tend to give it a little dose of fertilizer, and they tend to hold onto those a lot better because they’re gearing up towards fruit. If the tree knows it has that accessible to it, it’s going to be more prone to keeping what it needs.

– Audience Member: Thank you.

– So most citrus trees are actually self fertile, like you said. So they really don’t need pollination. A lot of trees, I personally, I’ve never pollinated a single tree in my life, like of citrus. I let them all do their own thing and I feel I get just as much produce as not. The one tree that really could use cross-pollination are tangelos. They benefit a little bit from that. But everything else tends to do their own thing, as long as as you have, like, a little bit of a breeze or nudge the tree every once in a while, and some actually don’t even need pollination to produce fruit. They produce some clonally through seed. Sure, encouraging leaf growth through a Meyer lemon that doesn’t wanna stop blossoming. [chuckles] Like I said, Meyer lemons are one of those varieties that just, like, never stop pumping out flowers. So what I think is very important is a little bit more intensity on the sunlight would definitely help. And if you wanted to, you can actually go through and pick a lot of those flowers off by hand. I know it kinda hurts to grab those and, yeah, to potentially knock out some of the fruit that you might get. But overall, that might help your tree in the long run. A lot of trees naturally regulate their own. So if they flower and they drop a lot of fruit, they’re going to wait a little bit before they flower again. Meyers are not like that, in my opinion. Like, you pick ’em and they come right back. So just continually picking those flowers off, not allowing those flowers to really develop. Try to get ’em when they’re first coming out, when you first see that little bulb come, and that should help encourage foliage over that.

[audience member speaking faintly] Sure, yeah, so fertilizer applications. I could’ve touched on that a little bit more too. So it really depends on how much you want your tree to grow through the winter, how active you keep it. So essentially through the wintertime, a lot of people recommend doing like a quarter or a half dose of fertilizer. Me personally, I keep my trees trucking along the entire way, like all year round. Give ’em enough light, that’s the important part, to be able to fertilize them. So if they actively grow, fertilize them as you normally would. However, if you see that kind of halting or you have more of colder conditions that would let them go into like a more semidormant state, then I would either half or quarter dose it. But again, I like to keep mine going year round. So I fertilize full-on all the time. Okay, so there’s a key lime that he has that lost a lot of leaves and it just pushes blooms, rather than pushing foliage, like what you’d want it to. So that’s a stress response or they call it stress blooming. Basically the tree thinks it might be going on the way out, so it’s trying to reproduce as fast as it can to prevail itself into the future. So what I would first check, as well as again the soil you might have it in, because that’s a big determining factor on how healthy it is, and once it’s healthy again, it should start to promote that foliage. Putting a little bit more harsher sunlight or fuller sun onto that plant will definitely help it. So maybe getting a grow light, putting it a little closer. Helping encourage that growth up. And again, the plastic bag, like I said, making that microclimate really helps encourage foliage growth over anything else that I’ve seen. So if I have a tree that gets like frostbit or burnt from the cold, like I forgot it on accident outside ’cause there’s so many of ’em. I tend to do that sometimes. When I bring it back in, I put that plastic bag over and it helps it recover so much faster. Put it on that germination mat and it’s a lot happier like that. Thank you, guys. [audience applauds]