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cc >> Good morning, everyone. Thank you so much for inviting me to give a presentation about growing blueberries in containers. Blueberries are a most popular crop in the United States, actually. And in fact, blueberries are very native to North America. In those days, Native Americans consumed wild blueberries. And even right now, modern days, we consume blueberries in different ways. Either it's a fresh consumption or you're making a pie, jams, jellies, you name it. It's very tasty.

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But it's not only the taste, blueberries have a lot of health benefits. It's very low in calories. One cup of blueberries can give only about 80 calories and has a very low sodium and no cholesterol at all. The other important thing about the blueberry is that it has pectin, which is a dietary fiber which helps in reducing your blood cholesterol level. The third most important thing I really like about this concept, and they have a type of a compound called ellagic acid. Under laboratory conditions, this ellagic acid helps in inhibiting some cancer cells. So that's really great. The third thing, blueberries are rich in vitamin C. One serving of blueberry contains about 40 milligrams of vitamin C which is equivalent to 25% of your daily consumption of vitamins. The fourth thing, blueberries also have some properties that can also prevent some bacteria formation in your urinary tract issues. And the fifth thing, blueberries also help in reducing the effect of glaucoma and also helps in improving the memories. And this study was conducted by USDA. The other important thing about blueberries, that it contains polyphenol, and this polyphenol which is known for antioxidant and anti-inflammatory properties which really helps in reducing actually any cardiovascular diseases, cancers, and age-related issues. So that's one of the reasons why we are going to crazy about blueberries. In the last 12 years, the per capita consumption of blueberries has been doubled. And the production of blueberries in the United States also has doubled. If you look into the 2000 data actually from the USDA, the blueberry back in 2000 was produced about, the total quantity of production was about 293 million pounds. But right now in 2012 the production was almost doubled to 452 million pounds, actually. So that really tells you that many people consume blueberries actually in the United States. But one of the typical things that as a gardener, though we all know about the health benefits of blueberries, we like to grow blueberries in our own backyard and have some daily fresh consumption of those things. So as an Extension agent, I do get a question quite often. Many people, after they've planted the blueberries, then they come back to me and ask me, how shall I grow blueberries? What kind of fertilizer do I have to apply? Why my blueberries are turning color? Why I lost my blueberries within a couple of years actually? Well, blueberries are not like a trial and error crop. It is very picky on what kind of soil it requires and how it wants to grow. Say, today we're going to learn a little bit about some of the unique properties, growing properties of blueberries before we jump into how to grow blueberries in containers. Blueberries are a deciduous perennial bush. And they're native to North America. And it does require a chilling period. Chilling period means a time frame that these buds have to be subjected into a cold temperature of 35 to 45 degrees Fahrenheit. So it typically needs about 800 to 1,000 chilling hours. That will help them to produce flowers in the following season. And blueberries, there are two types of buds. One is called a vegetative bud, another one is called a flower bud. The flower buds are easy to find out. They usually produce on the tips of the branches, and they're very plumpy. So you can't miss it. There's one other important thing that you have to be very, very careful about. It's not like any bush that you can make a cut. If you do make that, like a topping, then you're going to lose all you flowers. So you may wonder why my blueberry is not producing fruits. That's the reason. Beneath all these flower buds, you will see the vegetative buds. The vegetative buds are very narrow, and it just produces only leaves. One thing about blueberries that these flower buds are produced in the last fall. So early fall of the last year they started to produce a flower bud. So in spring they typically bloom. One thing about the blueberry flower is that in each of these flower buds you will contain a flower cluster about five to 12 flowers in the cluster. So you may think there is only one flower bud, but when this opens up you'll see a large number of flowers coming out. But these flowers are very sensitive to frost. So, for example, if we do have a very early spring and the temperature just spikes up, the bud may start to open up. Once it opens up and then we have a low temperature, then these flowers can get easily bothered. The other thing about blueberries also is that these buds do need some full sun. If you do plant then in a shade, a partial shade, the number of flower bud formation will drastically get reduced. During the growing season, it's very important to irrigate the blueberries. Frequent light irrigation is absolutely necessary for blueberries because 90% of the root mass, you get it only within the top six inches of the soil layer. So they are very prone to heat and moisture stress issues. So light watering, frequent light watering is absolutely essential in blueberries. The other thing also is that after you harvest the blueberries, usually you harvest them probably starting from mid to late July to probably about early August. That's the final harvesting stage you'll come across. During the time after you harvest them, these blueberry plants will start to produce and start to save energy for the next year's growth actually and for flower bud doubling up for next year. Generally the life expectancy for blueberries in a natural soil condition, even if you have a perfect conditions, 20 or 30 years. But in containers, if you're trying to grow them, your life expectancy is supposed to be about 10 to 15 years only. But one of the most important things about blueberries is that they need acid soil. They need a soil pH about 4.5 to 5.5. It's absolutely essential for blueberries. They need a well drained acidic soil which is also rich in organic matter content about 3% or more than that. So before you start buying your blueberry plant from your garden center, do a simple soil pH test. Contact your local county Extension office to do a soil pH test. Typically it costs only $5 plus shipping and handling fee for your soil sample. If you stick to the blueberry plant in the ground knowing that your soil pH is above 7, your leaves will turn pretty chlorotic. Chlorotic means yellowing. So on the left side you will see one of those leaves actually how it becomes very yellowing actually. On the right is a healthy blueberry plant which is planted in acidic soil which is dark green in color. If your blueberries are, if you plant it in a soil condition where your soil pH is a little bit acidic, say in the range of 5.5 to 7, in that range you can easily amend the soil. What you have to do, probably a year before you're planting blueberries, you typically amend them with some peat. Four to six inches of peat. You rototill it back into the garden soil, and then you can incorporate with some slow releases acid fertilizers like elemental sulfur. Elemental sulfur will be broken down by the bacteria and releases sulfuric acid back into the soil. But it's a very slow process, and it takes about three months. So if you start working your soil in the springtime, probably by the end of the summertime your soil pH will be reduced. So for sandy soil, typically you need to add about one to two pounds of elemental sulfur per 50 cubic feet. For the loamy soil, you need to add about three to six pounds of elemental sulfur for 50 cubic feet. There are other acid type of fertilizers that you can also get at the garden stores, like aluminum sulfate. Aluminum sulfate is a little bit toxic if you apply at a higher rate to the blueberry. It will burn the roots of the blueberry plant, so you have to be very careful in using aluminum sulfate. But though it's a very fast releasing one. Aluminum sulfate is a fast releasing one. It quickly acidifies it, but it's a little bit toxic if you apply at a high rate. Another type of fast releasing acid fertilizer is ion sulfate. Ion sulfate within a month can also acidify a soil, but it's very expensive and you need to apply six to eight times the rate of the elemental sulfur. So you need to apply in a huge quantity in order to reduce the soil pH. So it's cheap and best to go with elemental sulfur. But unfortunately, everyone doesn't have a perfect acidic soil. Acidic soil naturally you only find in certain parts of Wisconsin. Either in the northern most part of Wisconsin or maybe in the central part. But in most of the other regions in Wisconsin, your soil pH tends to be above 7, actually. In case of above 7, it is not worth battling against Mother Nature by incorporating elemental sulfur. I had a gardener actually, she's been amending the soil pH for the past 10 years, and her pH was about 7.3. To drop from 7.3 to 7.2 it took her about eight years actually by using elemental sulfur.

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And that is not a one time deal at all, actually, because every time you need to sustain the soil pH. So all you're doing with the elemental sulfur is sugar coating it, and the sugar coating doesn't last long in the soil particles. You have to be aware about it. In those kind of circumstances, if your soil pH is above 7, it's best to grow blueberries in a container. The reason is that in a container type situation actually you could be able to control the acidity level very easily. Second, easy to maintain. You don't have to think about if you want to spray for pests and diseases. It's very easy to do it. You don't have to worry about weeding. You don't have to think about if it's going to be too tough to prune or too tough to harvest those things. So there are a lot of advantages in container settings actually too. The other best thing is it's very portable. So nowadays people like to have a small space gardening. You don't want to have big, big bushes. So you're growing in containers, if you don't like the spot, you can move to another spot. It's very portable. But container growing also has disadvantages too. In a container growing one, you may have to think about repotting once in four to five years. If you start with a five gallon containers, once in four or five years you may have to repot it. If you don't repot it, probably you're going to reduce the life expectancy of these plants within 10 years. The second disadvantage is that in a container setting, actually, you can expect a lower yield. If you look in various catalogs, in food and vegetable catalogs actually, they may tell about various cultivars like Northblue, St. Cloud, Patriot. These are some common blueberry cultivars. They may yield about 20 pounds, 15 pounds per bush, but in a container setting you can get only about three-four pounds actually per bush. So don't get disappointed actually when you grow in a container setting because of the lower yield. So when you start thinking about growing blueberries in a container, the very first thing you have to make sure that you're selecting the right cultivar. In Upper Midwest area, there are three different types of blueberry bushes. We call the high bush, then we call the half high bush, and then we call the low bush. We don't go with the high bush type blueberries because high bush type blueberries get to about six to 10 feet tall bushes actually, okay? So we don't go with that. So typically we either for containers go with a half high bushes and low bushes. Half high bushes actually are a very small stature plant. They can get about only three to five feet tall at the maximum. Very hardy. They can go with a temperature of minus 35 degrees Fahrenheit. And they produce about small to medium sized blueberries actually. And you can start harvesting them either in second week of July to probably early August. Some cultivars in the half high blueberries that we've been experimenting in our demonstration trials I'm going to talk about pretty soon. We conducted a demonstration trial in 2011 at the Greenwood Botanical Garden with the help of our master gardeners. In the picture, you can see Helen -- and Lynn Clark. These are two of my master gardener volunteers who devoted their time in growing and maintaining these blueberry plants. So I'm really thankful for them. And we planted about like five different cultivars actually in containers, and we want to test actually what is the performance of these things. So these are demonstration trials. So in a demonstration trial, we grow actually Northblue. Northblue, in the catalog if you look, it gets to about four to five feet tall. The berries are large. High yield. In a container setting actually, the berries are large. They're about like a nickel in size. Very large. And it's very good in taste, but it has a slight acidic taste to it too. So you have to be aware about it and allow the flavor of it, the aroma is really great in Northblue. The only thing that disappointed is that it did not grow that really well. It grew only about 12 inches. So in a catalog, if you look, probably they would recommend three feet, four feet. In three years, only we got a growth of only about 12 inches or so. But don't get disappointed. It yielded only about two pounds actually per bush. So at least something is better than nothing. The one good thing is that in our container setting actually is that the leaves stayed healthy, perfectly healthy. So the soil media that we used, which I'm going to talk about pretty soon too, works out really great. The second cultivar is St. Cloud. I am totally impressed with this one. If you really want to envy your neighbor that you have a blueberry farm in your backyard, then probably go with St. Cloud. It's a very vigorous plant. Within three years, the growth had actually gone up to two to two and a half feet tall. It started producing multiple shoots.

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the yield. Unbelievable, 12 pounds from one bush. Can you believe that? It's amazing how many berries that I collected actually from this one single plant St. Cloud. But it has its own disadvantage. Everything comes with advantages and disadvantages, and the disadvantage in St. Cloud is that it's very mild in taste. It's not as sweet as Northblue. And the size of the berries are very small too, actually. As you can see in this photograph. Now, St. Cloud needs another cultivar in order to cross pollinate. Blueberries are one of those plants where certain cultivars are self-pollinators, certain cultivars are cross-pollinators. A self-pollinated crop means that you don't have to have another cultivar to produce a fruit. In a cross-pollinated one, you need to have two different cultivars in order to produce a fruit. Blueberries, certain cultivars, as I said, are self-pollinated, like Northblue is self-pollinated. But a St. Cloud is a cross-pollinated one. So if you're really confused, actually when you go to a garden store and are not really sure whether you need to buy another cultivar or not, I typically recommend always get two different cultivar. Even if the one plant is a self-pollinated one, it's always beneficial to have another cultivar too. Okay? The next one is Polaris. Polaris is also very similar to St. Cloud in a way that the growth is also amazing. Two, two and a half feet easily you can get it within three years. And it started producing large number of canes too. It very sweet. It's a little bit sweeter than St. Cloud, and at the same time it has a little tinge of tarty taste to it too. And it has a good aromatic flavor, but in terms of yield-wise, I was a little bit disappointed. I thought it might be producing just like St. Cloud, but it only produced only about three pounds per bush actually. Again, like St. Cloud, it's also a cross-pollinated plant. The next one is the Patriot. Patriot we planted only this year actually. Even in the first year I was really impressed upon the berry size. The berries are so huge. It's like a nickel actually. And it tasted really good too. So I really like Polaris, and I'm seeing a lot of potential for Polaris actually for home gardens. But Polaris is a self-pollinated one, but I still encourage you guys to go with another cultivar just to benefit, actually, the pollination one. The other cultivars that you can also try in your backyards are NorthCountry, NorthSky. Now, one of our master gardeners was so impressed with one cultivar, two years ago she found it in a garden catalog, called Pink Lemonade. The beauty of this Pink Lemonade as described in the garden catalog was that the blueberries are not blue in color. It has pinkish berries. And in the fall color, just like a burning bush how deep reddish-pink color produces, these Pink Lemonade also has a beautiful ornamental fall color. So we decided, okay, let's try it out in our container setting. Though it really grew really well actually, the height was about two and a half feet, it was really nice, healthy, but it did not produce any berries. And we didn't notice any significant fall color either. So it disappointed on Pink Lemonade. Now, I'm kind of told you guys there are three types of blueberry bushes. One is a high bush, half high. Now, this is a low bush type. The low bush type of blueberry is one of the common cultivars that you find in many garden catalogs is Top Hat. And Top Hat produces a berry just like a pea. Tiny, tiny, tiny, tiny pea-like plant. And it's a very low growing one. It can reach only a maximum height of only about 12 inches maybe, 12 to 18 inches if you're lucky. So it's very low growing, spreads out. So it's excellent for container plantings, especially if you're going to set these containers in your patios. So it's an excellent plant. So, once you picked out the cultivar, now you have to decide actually about this container setting. What type of containers you want to grow and whether you want to bury the container or you want to set it on the top of your patios. And what kind of fertilizer and what kind of media that you want to grow with. So in container settings actually, usually you start to plant blueberry probably in late in the April or early May before the buds open up. That's the best time to plant blueberries. And when you start selecting containers, always go with a minimum of five gallons actually. So if you shop around, they will usually give you one-gallon blueberry ones, but always go with a bigger container. The bigger container is much better. Or if you're lucky enough, if you have a 55-gallon drum, you cut it into two halves and use the bottom half. But needless, whatever container you select you need to have a good drainage hole. Have a good drainage hole, or four to five drainage holes actually, that's absolutely important because blueberry does not like too wet or soggy soil. They don't like standing water either. So that could be a number one killer actually. If you decided actually to plant blueberries in a container and you decided actually to set the blueberries either on your counter, table, or in a patio, always go with a different color. Don't go with a black color because black color tends to absorb heat. So with a different color of containers too. Here's a slide that you have to really pay attention on. In blueberries, actually, in container settings, we are using a soil-less media. We don't use any dirt. Real dirt we don't. So, in a soil-less media, the recipe is, there are two types of recipes. So the recipe number one is actually you can go with a one part actually with peat. One part with some pine bark. The pine bark, there are two versions you can get. Only you can get a notch, nuggets of pine bark. Then there's mini nuggets of pine bark. So if you walk into garden stores or into hardware stores, you ask for mini nuggets actually of pine bark. That helps really good. So get one part of the mini nuggets pine bark, one part of the peat and one part with perlite. You can easily get these things in garden stores, actually. And mix them all together really well and fill it in your container. Option number two, or recipe number two, you can also use shredded coconut core. Shredded coconut core can be expensive. So just be aware about it. If you do want to go with a coconut core, use two parts of coconut core, two parts of sphagnum peat moss, and one part of perlite. Mix them all together. So you can go with either one of these recipes actually. Now, fill the container with the soil-less media, and then when your taking the blueberry plant from your one-gallon container be careful not to disturb the roots. Gently lift it, and set the plant in the container. And then fill the edges of those containers again, inside edges of the container, with this soil-less media. And add about one inch of the soil-less media just right above the roots of this too. Then after that, pack up those media very gently, and then give a good drenching water. And then you can also add a two-inch of pine bark on top of the roots too. The two-inch of pine bark also helps you guys in conserving some soil moisture. Some people also like to add some sawdust too. You can also go with sawdust or with some pine bark. I typically go with pine bark because I usually have some extra amounts. Once you planted them in a container, site selection. Where do you guys want to set this container? So, as I told you guys in the very first beginning of my slides, blueberries do need full sun. If you really want to have a good flower development for next year, they do need some full sun. So try to find a spot where it gets full sun. But at the same time, make sure that site you selected to set this container is not subjected to any herbicide drift or not subjected to any kind of a salt drift or you don't pile up accidentally too much shovel on the side. Also, don't set it too close to the building. Sometimes the building heats up too much faster and can reradiate the heat back again. Because blueberry roots are very sensitive to heat stress too. But if you decided to set the blueberries in a patio, make sure that in a patio either it's in full sun or at least in a partial shade because in patios sometimes it can build heat too quickly too and sometimes can stress the plant. But one thing I really like about growing blueberries that I really like to bury the blueberry plant. There are a lot of advantages to it too. The reason is that if you set the blueberries just above the ground, it builds up heat inside the container very easily. When you too much heat, the roots get stressed out. So you remember always that any plant roots, they always like cool, moist conditions, and blueberry is no exception to it. So burying inside the ground gives some additional insulation to them too. Second of all, in the fall time, these blueberry roots need to be protected from the cold weather, and soil gives a good insulation to it too. So that's another reason why in spring when you plant them in a container, bury them in a container so you don't have to worry about probably in fall to bring them back again inside your garage or move them somewhere else. But if you're in circumstances, like if you're living in apartment buildings and things like that, you don't have a choice and probably may have to bring the container back inside an unheated garage and mound the edges of the garage out, mound the edges of those containers actually with about eight to 12 inches of soil or peat or something so that the roots don't get frozen out. So if you decide actually to bury the container in the soil, dig a hole deep enough it can completely submerge the container. Add one inch of gravel so that it doesn't block, the dirt really doesn't block those drainage holes. And set the container in such a way that the top rim of the container is about an inch above the soil surface because from our trial and error studies, what happened is that one of the containers was buried a little bit deeper and when we're trying to water it some of the soil from those edges came in and gushed in and get into the soil. So it kind of screwed up our demonstration trial. So we learned it the hard way. Watering. This is absolutely essential too. Sometimes you will see blueberry plants, either when you shop around in a garden store or when you plant them, even in the middle of the growing season the edges actually turn golden brown in color. And those are really a good sign of heat stress and moisture stress. And if it prolongs, also it can get completely toasted. So blueberries need frequent light watering. So, depending up on the weather, if it's a hot, dry weather, probably you may water at least once or twice a day. Especially if you set the container above the ground. Definitely two times a day where it is really hot and dry. But if you do have a multiple containers in your garden, probably it's best you can also use some drip irrigation and set some emitters in each of those containers. You can set two emitters on two sides of the plant. You can do that too. Fertilizing. This is a very key thing, actually. Blueberries need two types of fertilizer. One is a slow releasing fertilizer. Another one is a fast releasing fertilizer. So, the slow releasing fertilizer is the elemental sulfur, and the fast releasing fertilizer is the Miracid. So when you plant the blueberries in a container, four weeks after you planted them, add one tablespoon of elemental sulfur for every four-inch container. So if you took about eight-inch containers, add a sprinkle of about two tablespoon of elemental sulfur, and then use a trowel or maybe a finger and gently rake those elemental sulfur back into the media. And then you water it. And then probably by late spring, mid to late spring until probably mid July, you may need to fertilize with a fast releasing fertilizer, the Miracid. And when you use Miracid, you have to be very careful that you don't drench too much. So you had to be very careful about the rate. So, typically you add about one tablespoon per gallon of water, and you drench it. You may have to drench it two times in a month. So it takes about one to two times per month you may have to drench those blueberry plants. But one key important thing is that do not fertilize your blueberry plant after mid July. By mid July, the plants will have reached to its final stage of its harvesting. By that time, all the new growth, shoot growth, will all be completely stopped. You don't want to trigger any more of those new growth by adding some of those fertilizers. If you do add it, those new twigs or the new growth will become subjected to winter injuries. So do not fertilize after mid July. This is again a hard lesson that we learned. It's not only us that who blueberries, but also some rodents, also some birds, they do like it. So it's absolutely essential that you take all kind of precautions to protect these valuable blueberry plants. Also in wintertime, blueberry becomes very vulnerable to rodent damages, either voles or bunnies. So have a hardware cloth around these blueberry plants, and put up a bird net actually on top of it too just to give some protection from the birds as well as from the rodents because sometimes chipmunks can also climb on top of it and get into it too. A bird net does a dual purpose. Potting and repotting stuff. After four years, you may have to start thinking about repotting into another container. If you already started in a 55-gallon drum, you don't have to repot it by four years. But if you started with a five-gallon one, definitely you may have to start thinking about it. So go into a larger container, and do it early in the springtime. And use the same soil-less media recipe that I described before and repot it. When you're trying to repot it, do not disturb the roots again. Carefully lift the plant and set it into a new container and stuff it again with some soil-less media. The other thing also about blueberry is that you may have to start thinking about pruning the blueberry by the fifth year or so. In the first few years, first, second, third, and fourth year, if you do notice some die-back due to some winter injuries like these, you can prune those dead branches. Or if you think there are some branches very spindly or crowding too much a portion of the plant, you can start thinking about trimming those things. But they do not require too much pruning. It's a very simple bush. They don't need that much pruning. But by the fifth year, you may find some old canes that are more than pencil size in thickness and they may not set that much of flower buds on the tip of it. So those canes can be pruned. So the fifth year canes can be pruned. Usually the flower buds you will typically find in second, third, and fourth year canes. By fifth year canes, you will start to see the number of flower buds going down. So by pruning those fifth year canes, you're opening up space for some of the newer canes to come in and fill those spots. Now, the handouts actually are uploaded on the Garden Expo website. If you guys need some additional information about growing blueberries in containers, you can also download the fact sheet from our horticulture team website at hort.uw.edu. Our master gardener volunteers also have created YouTube videos on growing blueberries too. Thank you so much again for giving me this wonderful opportunity.

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