So my name is Lisa Johnson, and I am the horticulture educator with Dane County Extension, and as the horticulture educator, I do a number of different things, one of which is I run the Master Gardener volunteer program in Dane County, and I’m a frequent guest on Larry Meiller’s show. Larry is awesome, and I’m really privileged to get to work with him. I and my colleague Brian Hudelson give a lot of presentations, and you can catch my column in the Wisconsin State Journal on Sundays, except for this one, ’cause I’m here.

So what I’m gonna be talking about for tomatoes is pretty much a seed to growing it through the season. Not gonna talk too much about harvest. I’m not gonna talk too much about different varieties, as I’m sure you know there are different varieties coming out all the time, and I have not even seen the list for this year’s all-American selections, but I’m sure they’ve got some cool new ones. One of the ones that I looked at last year that we grew in our teaching garden, which is at the Dane County Extension Office, and if you’re in Dane County, please feel free to visit us there, is Midnight Snack, and it was the first time I’d had that one. It’s well, it’s bigger than a, it’s about that big [laughs]. That doesn’t help very much. It’s a little bit smaller than a ping pong ball, we’ll put it that way.

So it’s not really a cherry, but it’s not quite the size of a plum, but what was really cool about it was the coloration and the sweetness. The coloration is that it’s really super dark purple on the top. It starts out just a little bit and then it grows and grows and it starts to spread over the fruit, and then the bottom of the fruit is red. So it’s really striking to look at, and I thought it was pretty good tasting tomato too. So we try and grow a few. Yes, Lisa Johnson. [muffled speaking in audience] [audience laughing] I thought you said, “What’s your name?” Yes, the name of the plant is Midnight Snack. Yes, okay I was like, “Why does he wanna know that?” [laughing] Okay, moving right along then. All right, so growing tomatoes in Wisconsin. So this is kind of an outline of the talk.

I’m gonna talk a little bit about choosing varieties, what you might want to use different varieties for, then a little bit about growing from seed ’cause that’s really important, especially if you’re trying to grow one of the heirloom varieties. We’ll even talk a little bit about grafting tomatoes if you’re interested in learning how to do that. We’ll talk about proper watering and fertilizing before they go out in the cold, cruel world. Hopefully not too cold and cruel by the time you put them out, because as we all know, tomatoes are not very tolerant of cold, and then we’ll talk about the hardening off and planting out process. A little bit about tomato growing tips, which will include things like trellising and pruning the suckers out, that sort of thing. There’s quite a section on diseases because I would bet that almost anybody in here who’s ever grown a tomato has experienced some kind of tomato disease. A little bit about crop rotation, why that’s important, and then just a very little bit about harvesting and storage.

All right, first thing you need to know about tomatoes. If you’ve never grown them before, if you’re a novice, there are what we call indeterminate and determinate cultivars. So determinant ones are the short ones. So if you’re growing in a patio type situation, you’re growing in a pot, you’re growing in a raised bed, that might be something that you should look at doing. If you’re going to grow an indeterminate tomato, it’s really best to do that in the ground because they get so darn big.

So the reason that they are determinate or indeterminate is that with a determinate plant, the flower buds are at the branch ends, and they tend to ripen all at once over a couple of weeks. So if you are planting a lot of tomatoes and you’re planting determinate varieties, you need to be prepared for an onslaught of tomatoes all at one time. So clear your calendar, don’t go on vacation when your determinate tomatoes are blooming because they’re not going to wait for you.

So the indeterminate ones are the ones that we say they keep growing all summer. Those form their flowers in the axils of the leaves, so that’s where the leaf meets the stem, and they keep flowering and producing fruit all season long. It can include anything from heirloom large-sized slicing tomatoes to cherry and pear tomatoes, and one plant can produce quite a bit of fruit over one season.

So that’s the difference between those. So think about what you can handle in terms of harvesting, storing, cooking with tomatoes when you make your decision about what type of tomato to grow and usually, all that information will be on the seed packet if you’re growing from seed. If you’re not growing from seed, it should be on the plant tag. So it’s kind of an important thing to know.

Then there are the uses. If you enjoy cooking with tomatoes to make tomato sauce or roasting tomatoes, fresh eating, grilling, all those different kinds of things that we can do with tomatoes. There are some that are better than others for different uses. For example, the paste or Roma tomatoes are best for making sauces because they are quite a bit meatier. As you know, tomatoes are pretty soft and juicy fruit. So the softer and juicier it is, usually the better it is for fresh eating, but if you’re trying to make like tomato paste or tomato sauce, you probably wanna use one of the meatier varieties.

Then there is the aspect of disease resistance. Yes, there are some disease-resistant tomatoes. Brian Huddleston from the Plant Disease Diagnostic Clinic likes to tell the story of how the gene for tomato flavor and the gene for tomato disease resistance are located in such a way on the chromosomes that when you try and breed for one or the other, it’s hard to get both. So he said you can either get a really healthy tomato plant where the tomato tastes like cardboard or you can get a super disease-prone tomato that tastes really good. Well, they are being able to, through all kinds of genetic techniques, being able to breed tomatoes now that have some of each, but unfortunately a lot of our heirloom tomatoes that have the best flavor tend to be ones that are the most prone to disease. So that’s just something to keep in mind.

And I know over the past few years, because I get calls from people. People of course don’t call me when their tomatoes are doing awesome; they call me when they’ve got problems with their tomatoes. And so it has been so wet here over the past couple of years that the tomato diseases have just been rampant, and I’m sure if you grow tomatoes, you have experienced that. Unfortunately, we can’t shut off Mother Nature, but we can adjust our own watering techniques to try and keep leaves dry, which is one of the main ways that we help protect against tomato diseases.

So with resistant tomatoes, often if you look on the disease or on the packet, there will be a disease code. If you’re growing from seed, look for a series of letters. So V for example means resistant to verticillium. Well, VF is resistant to Verticillium and Fusarium wilt. There’s also LB, which is late blight resistance. A late blight is one that we always get really concerned about because that can be terminal for your tomato plant in a rapid period of time, unlike early blight and Septoria, where we spread out the joy of death for you know, months at a time. [audience laughing] That’s the you know, the slow death version. We also have tomato spotted wilt virus, and that one is one that often will affect the quality of the fruit, but doesn’t necessarily kill the host.

So the other thing to remember is that even though you may see these codes on the tomato seed packet, resistance does not mean immunity. If you have a susceptible host and you have proper environmental conditions and the disease is present, you may still get disease even though the plant is technically resistant to those diseases.

So a little bit about grafted tomatoes. If you have had a lot of problems with tomato diseases, particularly Septoria or early blight, which are the two that I mentioned that are the slow death ones, where you get spots on the leaves, and leaves start to shed here and there, and then they fall off, and you have these stems with tomatoes hanging from them; everybody’s seen that unfortunate situation. So that, those two diseases are both soilborne.

Now granted, if you get enough into the environment, they’re gonna be airborne as well, but one of the things that you can do if you’re really having problems with those sorts of diseases is you can get grafted tomatoes. Now you can buy them in your local greenhouse or garden center. They do tend to be pricey, but if your tomatoes are really important to you, that might be something to look at. What they do is they graft the upper part of the plant that has the tomato variety that you want to a root stock of tomato that is resistant to some of these diseases, and it is a fiddly process, but there is a really great video at the Johnny’s Seeds site that you may wanna check out, and it walks you through the steps. It’s not hard; it’s you know, you take a razor blade and you lop off the top of the tomato that you’re wanting to graft, make sure that you have the root system for the other tomato standing nearby, and then there are clips or other things that you can use to hold the two together until the vascular systems seal themselves together.

Problem is, you gotta have the right environment. It is a fiddly thing to do, and you have to really baby them along for a little while, but if you want to save some money and you’re an adventurous tomato grower, maybe you want to go ahead and try that. Otherwise, they do sell them for about six bucks a pop at your local garden center. So you know, if you’re growing like 40 plants, that’s probably not feasible for you economically, but you might wanna try a couple if you’ve had a lot of disease issues. So do check out that video if you’re interested in grafting tomato plants.

Did I miss one here? Yes I did, no I didn’t, okay. Okay, so we’ll start out by talking then about growing tomatoes from seed. So tomatoes, because they have a long growing season here in Wisconsin, we do need to start them from seed indoors. You can’t just broadcast the seed outdoors like you would with some crops. They just, they won’t bloom and produce fruit in time for you, especially with our unpredictable weather. You probably all experienced, like I did, the early onset of winter this year, which was quite disturbing, but, I mean it was after tomato time, but still. You know, we were having issues with the weather being unpredictable.

So it’s a good idea to try and get tomatoes that are gonna ripen earlier as opposed to later. So depending on your location, like if you’re in upper Wisconsin, you’re probably going to be putting out your tomatoes later. So you’re gonna be starting them inside later. What you usually are going to be doing is you look up on the internet when your supposed last frost date is. I say that with a bit of sarcasm because the last frost date actually is a median date. So there’s a 50/50 chance, one way or the other that you’re going to have frost. Those aren’t great odds as far as I’m concerned. So sometimes I like to wait about five days past the technical, so-called last frost date to put the tomatoes out.

Now I know some folks like to rush it. We’ll talk about wall of water and other things that you can do to try and protect your tomatoes should adverse weather conditions arrive, but usually you want to start your tomato plants between five and seven weeks before your area’s last frost date and again, that’s going to differ depending on where you are in the state. Down here in the Madison area, typically we have a, our Master Gardeners have a plant sale in about middle of May, fourth week of May and so we start our tomatoes usually around the end of March, otherwise they get too big. So usually sometime around March 15th to March 20th, March 25th even, if it’s a really large type tomato. If you’re living in the southern area of the state is a good time to start it.

Now if you’re living in the upper part of the state where maybe you’re not putting your tomatoes out till June, then you, you know, may want to wait quite a bit later to start your tomato plants indoors. The thing is if you start them too early, they get really long and leggy and they’re difficult to transplant. You can do it, but it’s certainly not as much fun as if it’s at a proper size.

The other thing to think about is “What am I gonna start my tomato seeds in?” We recommend using a seed starter. There are organic ones and traditional ones. So there’s lots of different brands out there. The idea is that a seed starting mix is very light and fluffy, so that it’s very easy for the roots to spread through the media. You don’t wanna use something that’s too heavy. Like some of the potting soil mixes can be pretty heavy for seeds to be able to you know, muscle their roots out through.

And you can start them, you can use flats if you want to and just seed them in rows, or you can start them in those little market packs, which are the four to six packs that you get at the garden center. You can use peat pots if you want to. You can start them in terra-cotta pots. The container isn’t necessarily so important, unless of course it’s peat pots and you wanna plant it in the ground, then you need to make sure to peel that pot off, but for most of these, you’re going to be growing it in the container and then transplanting it into the soil. If you started it too early, you may have to transplant it one more time from a smaller pot to a bigger pot. So usually if you’re growing the tomatoes for four to five weeks, you may find though, that you need to transplant. At the four to five week mark, you can certainly use a regular potting mix because they’re gonna be going out into the field fairly soon.

Now an optimal germination temperature for the media. Not talking about the air, but for the actual media is between 70 and 85 degrees. That can be very difficult to achieve without a heat mat or something like that. Now that’s just optimal. That doesn’t mean that they won’t germinate at 65 degrees, for example, or 60 degrees even. You just don’t want it to be too cold because if it’s too cold, they’re going to just sit there and not germinate, and that is one of the problems that we do see is when people have a media that maybe they’re growing their seeds in the basement; I did that. I had troubles with it because my basement is cold, but that’s the only place I could have a shut door that the cats wouldn’t get in. [audience chuckling] So there you have it.

So I ended up buying a heat mat and that, I was really startled at just how much that did increase my germination rate. If you use a heat mat, there are a number of different brands out there, but you do want to make sure that you get something that is appropriate for growing seedlings. And usually with tomatoes, they germinate very well, even if it’s a little bit older seed, usually they germinate pretty well. 6 to 12 days is about when you should start to see some little leaves popping up among the soil.

Another thing to think about is appropriate lighting. One way to not get tall, stretchy tomatoes is to make sure that you have good lights. I don’t really recommend using the plain old fluorescent tubes we used to recommend. You could use a blue fluorescent or white fluorescent tube and then what we call a warm white fluorescent. So you kind of had a blue and a pink cast to the two different types of lights. It really works a lot better if you are able to use an actual grow light or if you can afford it, an LED light is really awesome as well. I’ve seen some really nice results with some of those, but some of them can be pretty pricey as well.

You want to make sure that if you’re using natural light instead of a grow light, that you keep rotating the flats because what’s gonna happen is your seedlings are gonna say, “Ooh, there’s more light next to the window. “I’m gonna bend that way,” and so you rotate them to keep them growing straight up so that they don’t keep bending towards that light source. Now if you’re using grow lights, even though they seem really bright, they’re still not as strong as natural sunlight. And so you want to keep those lights on about 16 hours a day. You don’t want to keep them on 24, necessarily. That doesn’t do any, doesn’t add any value, but the research that they’ve done shows that about 16 hours is about what you want, and you wanna make sure that the plant tops are just a couple of inches from those lights, and that’s another reason to be careful about the type of light that you use, because obviously you don’t wanna have something that gives off a lot of heat and fries your tomatoes. You wanna fry your tomatoes yourself when they’ve actually developed fruits. So trying to keep it a couple of inches from the lights.

What we do is we have our lights on chains and as the plants grow up, we just move the chains up so that the lights can move. Now if you don’t have the ability to do that, what you might want to do is instead do the other thing, which is you put some boxes or bricks or what-have-you underneath the flat when they’re small, and then just keep removing them as the plant gets bigger. So either the plant or the light has to move to keep the leaves in the appropriate orientation. The great thing about grow lights is that technology has gotten so much better over the last 10, 15 years, especially now that we do have LED lights available. They are getting really close to regular sunlight, so that’s awesome. You can see in this picture, it’s a little bit hard to see, but these are probably about four inches from the lights, and they’re also not tomato plants, but it was the best picture I could find. So these should be actually moved a little bit closer.

A little bit about watering. Seedlings are delicate and fragile things. So you need to make sure that they don’t dry out, but you need to make sure they’re not swimming in water either. It’s very easy if you’re growing in the little plastic packs you know, that fit into a flat. It’s easy to have that water flow through and not realize that in the bottom of the flat, you’re building up you know, half inch of water. So it’s a good idea after you’ve watered, to lift up some of those and just see what you’ve got on the bottom. My favorite tool is a turkey baster that I don’t use for turkey, and I stick it in there and suck up any of the extra water that’s in there so the seedlings aren’t sitting in water. You can water them from below if you, you know, so desire. If you wanted to fill up the flat and you know, to about half an inch, no more than that and let them sit for about 20 minutes, it will absorb the water and then you pour the water off. It’s just, it’s a little bit more work to do that. So you don’t wanna allow those plants to be sitting in water for long periods.

Now when you first are germinating the seeds, if you wish, you can use humidity domes. They tend to be fairly expensive, but they do work really well. So you know, maybe you want to invest in a couple of them. If you’re gonna invest in some, I would invest in the taller ones rather than the shorter ones. And those don’t need to be on very long. Once your seedlings are half an inch tall or so, you can definitely take those humidity domes off. It’s just when they’re very small that they can be helpful. Also when you’re watering in, make sure that you don’t have a watering can that has a big hole on it because it’s easy to totally wash those seedlings out. So I recommend using a watering can that has what they call a rose on the end, which is that big round part that has the holes poked in it. One with some very fine holes in them, small holes in them, not large holes.

The other thing that I’ve found works really well is if you have a water bottle, you can poke some holes in that. Just a plain old plastic water bottle and kind of squeeze it a little bit. The Master Gardeners have really enjoyed doing that at the office because it’s very precise and you don’t end up watering the table or the floor quite so much. Also keep in mind that it’s possible to water from the bottom or any way to keep the leaves and the media wet, from being wet for long periods of time. That’s another reason that that little squirt bottle thing works out really nice is because you can water right at the base, whereas with a watering can, you are gonna get the leaves wet. If the leaves are wet for a little while, that’s fine and dandy, but what we do worry about is fungal diseases, because fungi like to germinate on wet surfaces. So if the leaves are wet for too long, then you can have issues with that.

There are also diseases that will attack the root system. If you’ve ever had what looks like a happy little seedling that’s growing like this and all of a sudden it does that, and you look at the base and it’s kind of shriveled up. That could be a disease called Pythium or Phytophthora, one of those two. There are a few others, but those are the most common. And that symptom is called damping off, and you often will find that with soil that hasn’t been properly pasteurized or with just plants that have been kept too wet.

So with the tomatoes, you do wanna allow some watering between, or some drying between watering, but you don’t want to allow those seedlings to get too dry again. They’re fairly fragile, so you do need to keep an eye on them and keep checking them. Especially if you’re growing in a small container and they start to get you know, about an inch tall, you might want to think about transplanting them just so that you don’t have the worry of them drying out. So when you have seedlings, it’s not a good time to go on vacation, unless you really trust your seedling babysitter.

So here’s the humidity domes. Again, the small ones, they’re fine, but they don’t allow the plant to get very big.
One thing you don’t want to have happen is have the leaves get plastered against the top of the dome, and especially if they’re wet because again, you can end up with fungal issues that way. Again, you don’t have to use these if you don’t want to. It is helpful, but it’s absolutely not required.

Then fertilizing seedlings. The thing about seed starting mix is that although it’s wonderful and light and fluffy and all of that, it has very little nutrition in it. So once the seedlings have germinated, you’re getting good roots, they’re about an inch tall, then you need to start thinking about fertilizing. Now if you decided not to use a seed starting mix and instead you used an organic product to start those in, then you don’t necessarily need to worry about the fertilization, or you can use something like compost tea. You can use compost tea also if you’re using the regular seed starting mix. The problem I’ve observed with some organic mixes for starting seeds is that they may be a little bit heavy and they might stay wet too long. So that is one thing that can happen.

All right, so when you start using a fertilizer, whether it’s an organic product like fish emulsion compost tea or a traditional 10-10-10 fertilizer, especially if you’re using the traditional product, be sure to dilute it to about half strength. And you want to fertilize about every other week. Now if the seedlings should start to become an off-color, yellow or something like that, then you can up the amount of fertilizer, the strength of the fertilizer that you’re using. And once they get to be about four inches, you should definitely do that. As I mentioned, there are organic products you can use if you prefer not to use the traditional ones. Now once the plants start to get about three to four weeks old and they’ve got a number of strong, true leaves. Not the cotyledons that first come out, but the actual true leaves like in the the picture here. You can see the cotyledons are at the base. That’s the little tiny leaves at the base. The true leaves are the ones at the top.

So there is something that we do with tomatoes called pinching, and that, you want to make your pinch right above a leaf axle. That’s where the leaf hits the stem, and you don’t wanna leave a long piece of stem. That would be called an internode, but you also don’t wanna have it so close to the leaf that it dries out. The idea that you’re, the whole thing behind pinching is that you’re forcing the plant to branch out by removing those top leaves that have an oxygen supply, it will create a, or it will take away the suppressing effect of that oxygen by removing those top leaves and allow it to start branching out. So you get a plant with more branches when you do pinching.

Hardening off then and planting out. So again, you wanna look at what your last frost date is and also, even though you’ve looked at your last frost date, take into consideration what the weather is actually doing. If it’s gonna be below 50 degrees, I’d even say 55 degrees, then it’s probably too cold to put those plants out. They’re very sensitive to cold temperatures, and it can stunt them if they’re put outside too early. The hardening off process is where you put the plant outside for a few hours a day, maybe in a shady location so that it’s not subjected to direct sunlight, then you bring them back in at night. It’s a good idea to have a wagon or a wheelbarrow for this, if you have you know, a couple of flats so that you can move them in a timely fashion.

Also keep in mind that if the temperature overnight is gonna be below 45, that you may want to protect those tomatoes, and there are various ways that you can do that that I’ll be talking about in just a minute. Also, they will not start producing fruit or flowers until the night temperatures are over 55 degrees. So sometimes we have issues in midsummer when we get a cool spell and the temperatures go below 55 or quite close to 55 for you know, a few days where tomato buds may actually abort.

And if your tomatoes went, by the time you’re gonna put ’em out, if you find that they’re leggy, that’s okay. With tomato plants, unlike a lot of other plants, they produce what we call adventitious roots. Those are roots that will be produced anywhere along the stem. So if you have a leggy tomato, you can plant it up to like four inches deeper than the base of the soil. Kind of lay it in there sideways and prop up the stem. Make sure that obviously, you don’t break the stem, but that’s how you can deal with leggy tomatoes. Make sure that you prune off any leaves that are gonna be underground, but they should do fine.

So here’s the protection. There is a product called Wall-O-Water. There are other brands available as well. You don’t have to have the pink one, but they have done some research that shows that red plastic put around the base of the plant can help the tomato to be up to 20% more productive, but you need to make sure that the tomato can also get water. So you need to cut out around the the base so that the tomato plant can get water, but the thing about water is that when it’s cold at night, it is going to, as it cools, give off heat, and that will help protect your tomato against those cold temperatures. Now obviously, if your tomato is sticking out the top like it is in the second photo, the Burpee. com one, that part of the plant is not going to be protected. So you would need to find some way to cover that.

Then pruning out suckers. What suckers are, are side growth, and Brian really, Brian from the Plant Disease Diagnostic Clinic really recommends doing this. Also my friend Claire Strader, the organic farm educator from my office. The reason for that is because it will help to keep the canopy kind of thinned out so you’ll get better air circulation and better development of the fruits. What the suckers tend to do is they start to form their own branches and flowers and fruit and it can get very congested. Now you don’t need to prune out every single last one of ’em by any means, but especially when it’s young, it’s helpful to do that. I also, and you can see they’re pointing to where those suckers are, and you can see they’re between the stem and the leaf stem.

One thing to think about too is to remove those bottom leaves once the tomato is in the ground. Again, the Septoria and early blight come from the soil. So if you have less material for spores to splash up on as you water, then you have less disease. So that’s why we prune off those bottom leaves. Another great thing to do is mulching, and I think I talk about that in a few minutes.

So a little bit more then about those suckers. What the suckers do is they suck energy out of the rest of the plant, and they delay fruiting on the main stems, and you want most of your fruiting to happen on the main stems, both because you’re going to get bigger fruits that way, but also for structural strength. So the suckers at the bottom are going to be stronger than the ones near the top because they’re being able to pull from the root system, which is you know, fairly close at the bottom. Also by allowing more air circulation and more sunlight in, you’re going to be encouraging more fruiting and better fruit production and larger fruits. And again, the unpruned plants tend to start to lean and become wider, and you wanna have good spacing between your plants in the garden again, because air circulation means less fungal problems because you’re gonna get better drawing of the leaves. So again, you don’t need to prune out all the suckers, but you should at least get the ones at the bottom.

A little bit about disease prevention. Mulching again, removing those lower leaves. Crop rotation, very important.
If you don’t have enough room in your garden to rotate, you may wanna think about growing your tomatoes in pots where you can move them around. What happens is that diseases tend to build up in the soil over time. And then again, air circulation, grafting, fall cleanup. Taking any diseased material out of the garden is really important.

Trellising is also really important to keep the fruit off the ground. So there are, I could do a whole lecture on different kinds of trellising. So I’ve just given you a couple of options here to look at. There are many different ways to accomplish this. The main thing is to just make sure you have a sturdy enough support, particularly if you have an indeterminate tomato.

Okay, now the disease part, everybody’s favorite part. Let’s talk about blossom end rot. Usually you’re gonna see this on heirloom tomatoes or the first tomatoes of the season, and it’s actually not a disease, it’s a calcium uptake problem. Calcium is taken up in the water stream through the roots. If you have inconsistent moisture, then your calcium flow is inconsistent, and calcium is used in cell walls. So what tends to happen is the blossom end of the tomato doesn’t get enough calcium and the walls start to collapse, giving you that particular symptom. So the easiest thing to do is keep your watering consistent. Not been a problem. Mother Nature has been quite generous lately, but of course too much water can be an issue as well. There are calcium sprays available that you can spray on the fruits though, if you prefer to go that route, and we do have a fact sheet on this.

Cat-facing we don’t actually have a fact sheet on. That one is more common on the larger size tomatoes, and it’s more common when we have cold nights. What happens is you get inconsistent growth of cells, and so some cells are growing faster than others. So you get this gnarly kind of tomato, and it can be a problem with those deep holes because you can get pathogens in there and then the whole thing rots, and it’s very, very annoying. We also time, we’ll see it sometimes when somebody’s used 2,4-D type herbicide. And one thing you can do is keep them out of cold, wet soils and avoid really high nitrogen levels.

Sunscald we tend to see when there’s been a little bit too much pruning in the canopy or when you’ve lost a lot of leaves due to Septoria or early blight, and all of a sudden the tomato that had some shading is subjected to full sun and it responds by having sunscald on it, which is unfortunate. You can usually slice that off and eat the other end of the tomato.

This one’s always very sad. If you have black walnut trees, you probably know that they do not get along with tomato plants. It causes a problem with the vascular system, and the tomatoes start to look like they’ve got a disease or that they’re very dry and no matter how much you water ’em, because the root system and the vascular system is compromised, that’s not going to help. So if you do have black walnuts, grow in containers or grow in raised beds.

This one is not really too much of a problem. We tend to see it again, more on heirloom varieties. Again, it’s a question of cells not maturing at the same rate, and you tend to see it on those bigger varieties more often. So you can still eat those tomatoes or fry ’em up if you so desire because after all, hey, they’re green. So what you can do though if you don’t wanna eat that green part is just cut around it. A lot of that has been bred out in the more hybridized varieties that are newer.

The leaf diseases that we also dread, early blight and Septoria look fairly similar, they cause spots on the leaves, and you treat them pretty much the same way. Both in terms of if you care to use traditional chemicals. I don’t usually recommend spraying on plants that you’re gonna eat fruits or particularly leaves off of, but there are some things that you can do, and so I wanna be able to tell you how to differentiate.

So the early blight, you can kind of see they have a bigger spot and it looks like it’s got concentric rings, kind of a bull’s-eye pattern in it. That again is soilborne, and so if you mulch to make a barrier between the soil and the plant, that will help with that, but when we have a super wet year like this last year, it starts to become airborne, and there’s not a whole lot that you can do other than get resistant plants and again, that’s not gonna necessarily guarantee it anyway. The big problem with this of course is when you lose leaves, you lose photosynthetic ability, and the plant can’t support a whole lot of fruits. So it tends to limit the amount of fruits that you can harvest. And also make sure that you do good cleanup at the end of the season and get rid of all that diseased material, actually before the end of the season, if at all possible.

Late blight, this is the one that comes in and kills the whole plant in a rapid fashion. When we hear about this, I usually, I subscribe to Amanda Gevens’ newsletter. She’s our vegetable pathologist. So any time late blight starts to come near us, like when it’s in Michigan or Minnesota or something, she will send out a newsletter, and she’ll also let me know when it first shows up in Wisconsin and where it’s shown up, but it does tend to travel on air currents, particularly when we have strong storms. We’ve had a lot of rain, we’ve had a lot of strong storms, so we have had some problems the last couple of years with late blight in particular areas.

It’s very distinctive. The whole leaf or stems will turn kind of fuzzy and sort of collapse. You’ll see large spots on fruits and those will collapse. You can certainly bring a sample in to Brian’s clinic to have that diagnosed if you wish. Theoretically, so far it does not overwinter here. So it comes in on infected seedlings and on those air currents that I mentioned. There are good news. Some late blight resistant tomato varieties and again, this presentation is gonna be on University Place as well as it’s on the Garden Expo site, so you can get a hold of that list. It’s also on the late blight fact sheet, and there are more than these.

Septoria has smaller spots on the leaves. Typically, they have a light interior and a darker-colored border. Might be kind of brown, might be kind of black or even purple on the outside of the little lesion there. It does the same darn thing that early blight does, which is that it starts to defoliate your plant from the bottom. You can start out by trying to remove you know, some of the affected leaves, sometimes that can help. Again, try and keep the leaves as dry as possible, water at the base, use your mulch, resistant varieties. With again, good garden cleanup is helpful in controlling this.

Crop rotation, what you wanna do is you want to grow families of plants not in the same place every year. So not only your tomatoes in the same place, but the other tomato family relatives. So the potatoes, your peppers, your eggplant, tomatillos, petunias and flowering tobacco, those are all members of the Solanaceae family. So you can’t like move your tomatoes and instead plant peppers in that same spot, because everything in that family is susceptible to the same types of diseases and will allow those to continue to build up in the soil because you’ve got food for it, being that it’s a plant in the same family.

So what you’d wanna do is say you grow your tomatoes here one year, then you grow beans in that same spot next year, then you grow something in another family, maybe lettuce the next year before you circle back to tomatoes. And we do have a fact sheet on it. I’m not sure that Brian has that, but we have a list of the plant families and what crops are part of those families so that you know that you’re not accidentally putting something else in the same family in the same spot. And again, if Brian doesn’t have it today, you can find it on his website.

So just a bit about harvest and storage. So first of all, when you harvest your tomatoes, if you do have some that have cat-facing or sunscald or something like that, use those right away. Don’t try and store those with the other fruits. You’ve probably heard the old saying, “One rotten apple ruins the barrel. ” Well, it’s true with tomatoes as well, and the reason for that is that as plants are bruised or damaged in some way, they start to emit something called ethylene gas, and that is a plant hormone that speeds up the process of ripening and rotting. So if you have a damaged fruit in with other fruits, it’s going to cause those other fruits to start to have issues as well.

Keep in mind that tomatoes should not be refrigerated. What tends to happen is that when they get cold, the sugars in the tomato fruit start to turn into starches, and so it’s not sweet anymore. It’s like bleh, it’s kind of bland and mealy and not so good. So don’t refrigerate your tomatoes because they won’t develop the flavor fully. If you do have to bring in tomatoes because it’s going to frost outside, you can ripen them in a paper bag. For the same reason that we don’t wanna have bruised tomatoes, they will actually in the paper bag, it will start to concentrate that ethylene gas and they will start to ripen. So you can also put them out you know, on a windowsill, but you tend to get better, more uniform ripening just in a good old paper bag, not very high-tech. Then if you’re going to you know, freeze, dehydrate, or can, that is all great. Again, you don’t wanna let the tomatoes sit around for too long before you use them, just because they’re a soft fruit and they tend to start to decay.

So these are some resources that I’d like to recommend. At our learning store, we have all of our longer types of publications. There’s a great one called “Homegrown Tomatoes for Wisconsin” that has recommended varieties, and they do update that on a fairly regular basis. Some of the newer ones we haven’t evaluated completely, but usually AAS selections perform pretty well. So if you wanna try some of those new AAS selection plants, I’d encourage you to do that. We also have one, it’s more for commercial growers, but it has a lot of good information about diseases, insects, et cetera and that one’s “Growing Tomatoes, Peppers, and Eggplants in Wisconsin. ” There’s also one about growing and preserving vegetables as well as canning safely, that’s a really important thing to think about when you’re canning, that you do it properly.

And I think that’s pretty much the end of my talk. The fact sheets that I’ve mentioned are listed here at the bottom. Again, you can find those at Brian Hudelson’s Plant Disease Diagnostic Clinic or PDDC website. So thank you very much, I appreciate your listening.

I’ll be happy to take any questions that you might have.

Yeah, so the question was about slugs and tomatoes. You’ve tried the beer traps. What the slugs are actually looking for is the yeast that’s in the beer. Were you using light beer by any chance? ‘Cause that doesn’t have as much yeast. If you’re using beer, you want to use something that’s like a lager, otherwise you can go to the grocery store and get yeast in packets and mix it with a little bit of warm water and set that out. They really do like that a whole lot. The other thing is you could try diatomaceous earth, making sure that you take all the lower leaves off of your tomato plants to not provide a little ladder for your slugs so that they have to crawl up the stems that have little hairs on them, which are not quite so comfortable for slugs. I mean they’ll do it, but they have an easier time if you give them a ladder, so don’t give them a ladder.

You can also put out short boards or grapefruit halves or something like that. The slugs will crawl into them at night and then you simply pick those things up in the morning and dispose of them. There’s also Sluggo, which is iron phosphate tablets. I’m not sure whether that is, I mean it’s an organic, I mean those you know, those elements are organic, but I don’t know whether the product because of the way it’s manufactured is considered organic. So you’d need to check and see if it has an OMRI, O-M-R-I label on it, but diatomaceous earth and the other products that I mentioned, you can try those. If you’re trying to go organic and you’ve got really good organic matter in your soil already, then you could use something like compost tea on a weekly basis.

If you’re using traditional products and you’ve got decent soil fertility, you could use a slow-release product that goes for three months. That’s usually granules that you scatter around, or you could use something like Miracle-Gro a couple of times a month. Usually you know, once we get farther into the season, like August and so on, I usually start pulling back on doing any kind of fertilizing, but you know, for those first few months where you want to get it going.

With tomatoes, you do need to be careful though, not to give too heavy of nitrogen because that can come at the expense of the flowers and fruits. So the problem or the good thing about the organic products is that they’re less concentrated than something like Miracle-Gro or another water-soluble fertilizer. So you usually don’t have to worry about that kind of thing happening with those kinds of products, but you need to add them more often because they’re less concentrated. And usually we don’t, at least in this area of the state, we usually have very high phosphorus and high potassium. So usually it’s nitrogen that you’re lacking or calcium.

The question was about long,leggy tomatoes. Don’t forget, you can pinch first of all, but what the fan typically does is it is going to allow better girth on the stem because the plant’s being moved back and forth like that. It may help a little bit in keeping the length down, but I think you’d be better off with pinching if they get too tall.

Really great question, how big of a container do you need if you’re growing tomato plants in a container? It’s gonna partly depend on whether you’ve got an indeterminate or a determinate plant. If you’ve got an indeterminate plant, I’d say probably a, I mean, the bigger is better obviously, but a 10-gallon pot should be absolutely fine. Bigger one, 15 gallon or even something like a half barrel is good. For determinants, you could use, a 10 would be ideal. You can probably do it in a five gallon though, if you had to. I’ve seen people do it in five-gallon buckets and as long as it’s you know, one of the shorter determinate varieties, that’s fine.

What type of mulch? There are different things that you can use. Some people like to use newspaper and then put grass clippings on top of that, assuming you have not treated your lawn with anything. You don’t wanna put treated grass clippings on. You can use straw, clean straw and you can still use the newspaper layer if you so desire. Some people like to use cardboard, but you need to make sure that you have an area of it cut out so that you can have the plant absorb water. Personally, I like the straw or hay, and you wanna try and get some, that’s what they call clean straw so that it doesn’t have a lot of weed seeds in it ’cause that is annoying. [laughs]

The question was what’s my favorite trellising technique and again, there are a ton of different ways to do it. Some people will wind the plant around a string. I don’t think that tends to provide enough support. I don’t like cages because they tend to, if you have an indeterminate plant, it gets too congested in there, and you get squished tomatoes as well as poor air circulation. I really like using cattle fencing that is supported by fence posts and then using tomato clips, those little plastic clips to hold them onto the fencing. The nice thing with that is that you can, as new branches come out to the side, you can kind of guide them in there, and they’re easy to clean off at the end of the season. So I like that best, but I have certainly used just regular stakes and tomato clips or twine. So lots of different things you can do.

Yeah, I recommend that with all my seeds, starting that you make sure that the mix is moistened first because otherwise, the water will run right through, and then you’ve got your little seeds kind of floating around on the surface, it’s very sad.

The question was about volunteer tomato plants. Just a show of hands, how many people have had volunteer, yeah [laughs]. A lot of people. It is pretty common, especially with cherry tomatoes, and it’s interesting that those seeds overwinter because you know, tomatoes are not particularly hardy as far as cold is concerned, but yeah, I’ve had tomatoes come up from seed a number of times. Sometimes the fruits that they produce are not so great, other times they’re really good. It just depends on what the two parents were, because you know, you have open pollination. For the most part, tomato plants tend to be self-pollinated. So usually you get something that’s pretty true.I expect that’s probably what’s happening in your situation, but with the heirlooms, all bets are off. [laughing] You can get all kinds of different things. If you want more control over what the tomatoes taste like, then it’s best to do it from packaged seed.

Okay, so the question was about having tomato seedlings get kind of long and leggy before you put them out, and what is an appropriate air temperature, did I get that right? Okay, so with tomatoes seedlings. First of all, you can probably mitigate that problem by starting them a little bit later, but also by making sure that you don’t over fertilize with nitrogen. An ideal kind of temperature would be like about 70 degrees during the day and 60 at night or so. If that is not doable, at least 65 and 55 would be what I’d recommend.

A lot of you know, it’s interesting because the air and the media are two different things in terms of temperature, and if you have the air too hot and the media is too cold, then you have problems because the root system isn’t growing fast enough to keep up with the air temperature that’s forcing the plant to grow faster. So you wanna make sure you have kind of a balance between the media temperature and the air temperature.

The question was about rotation, if you could not rotate, but use soil amendment. The problem is that those fungal spores tend to build up in the soil because they have tomato roots and tomato leaves and fruits to feed on. So even though you’re amending it, you might be diluting the spores, but you’re probably still better off trying to rotate and starve them basically, is the idea. There are some soil-borne diseases that have a super long viability period, like you know, 10 years or more. For those, it’s really difficult to control through rotation ’cause usually we recommend a three to four year rotation, and they’d still be there if you use that. So it’s important to know what the issue is.

Yeah, that’s a tough one. The question was how do you prevent cracking? Cracking is often due to a lot of water and the growth rates of the fruit. So we tend to see it more when we’ve had, say a dry period and then a really wet period. We also tend to see it more on some varieties than others, and when we have a really wet year, it tends to be problematic. Heirloom varieties are more, unfortunately susceptible to that, and particularly large heirloom varieties are more susceptible, but I have seen a fair amount of it on Sungold, which is you know, a cherry tomato, and I saw more of that last year when again, right around the time when you know, it was tomato picking season, we got all that rain and then started to get that cracking. Usually they don’t recommend using sand for more drainage. They recommend adding organic matter. One thing you might wanna try and do is like build up a berm sort of situation or even use a raised bed. Raised beds usually drain pretty awesome, but it does involve some labor.

[laughs] The question was about why don’t my tomatoes look like the ones that I buy at the garden center. Those have typically been raised in a greenhouse situation, where they’ve got absolutely optimal fertility and water and both media temperature is high and the air temperature is high. I work part-time at a local greenhouse and it’s really amazing. We can get a saleable crop starting with a seed, it can take like three weeks, and you’ve got a plant that’s you know, about that tall and ready to go. It might take quite a bit more than that in a household situation, but that humidity and heat is the thing that pushes it along. So yeah, it’s hard to achieve at home [laughs].

[audience applauding] Thanks.

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