Growing Backyard Grapes Slide 1 Hello, this is Gwen-Alyn Hoheisel and this is a presentation for all you backyard growers who want to make their garden edible. Slide 2 When you are going to grow grapes, you want to start with the why do you want these grapes? Do you want them to eat them fresh or do you want them to process them into the juice, jam, or wine. Or perhaps you really don t care about the grapes, you just want the grape growth to make it into a shade or an arbor. As we go through this presentation keep this in mind what the purpose is for you to grow the grapes because it might change how you grow them or your variety selection. Slide 3 But let s first start with some of the basic needs of all grapes. So all grapes need a sufficient growing season, at least 160 frost-free days. They also need adequate sunlight and heat that is greater than 2500 growing degree days (GDD). And growing degree days might seem like a very scientific term but really it just says the maximum temperatures and the minimum temperatures that a plant will grow. And you can often find growing degree days as an option on some of the weather websites for your area. You also need good air drainage. You don t want to put these in a little cold pocket where you will get temperatures below -10 degrees Fahrenheit. You also need water and nutrients. And let s not have soggy soil, so you do need good soil drainage. Slide 4 Other things that you need to be aware of when growing grapes is how cold you get in the winter. So the colder that you get, the more cold hardy a variety that you need. You also need to be very careful of Spring and Fall frosts. Slide 5 Okay, so there are three main varieties. And the first one would be American varieties and those all fall under Vitis labrusca which is the scientific name but the origin of these is mainly the eastern US. And they are wonderful in that they are very cold hardy, they have very good vigorous growth, and they are really wonderful in that they are easy to grow because they are disease and insect resistant. Some of the names that you might know these as are Concord or Niagara. But these are a great variety for growing rapidly with big leaves. Page 1 of 9
Slide 6 Another classification of a variety is the European varieties. These are all Vitis vinifera. So typically they are all what we think of as our traditional wine varieties: chardonnay, cabernet, there are also Thompson seedless. These grapes primarily originated in the Mediterranean, they are not as cold hardy and they usually have an upright growth pattern. Slide 7 The last major category of varieties is all of those grapes that fall under a hybrid. And hybrids have a cross between American characteristics and European characteristics. So they can be intermediate in their cold hardiness, they can have various forms of growth, and depending on if they are more American, which is pretty disease and insect resistant, or if they are more European, which is more susceptible, they can vary in their insect and disease resistance. And there is a large variety of different hybrids. And primarily, the Eastern U.S and Midwest have started to grow a lot more hybrids than the Western states Slide 8 Now let s talk about some certain grapes that might be good for certain uses. With table and raisin grapes, if that is what you want to use your grapes for, there are many American native varieties such as Concord, Niagara, and Catawba, those are all good for this use. With European varieties there are Flame and Thompson Seedless. And with that seedless it is very nice to make raisins obviously from seedless grapes. So if you are going to look at some of the hybrid, which is with the American and European flag icon, try to find some that are seedless or sweet and these will dry down to wonderful raisins. Slide 9 With juice and jam, almost any variety will work but the majority of juice that is out on the market is made from Concord and Niagara which are both American varieties. If you are looking at European varieties, almost any wine grape will make great juice or jam, however I recommend ones that have a little bit of a sweeter flavor like Muscat, Chenin Blanc or Riesling. And if you like the flavor of the grape it will make a wonderful white jam. And for the hybrids really almost any will make a good juice or jam because many of them have natural sweet tendencies already. Slide 10 Making wine from the grapes that you grow is an obvious use. And most of the wines that are on the market are made from European varieties. So those are things like the pinot noir, chardonnay, merlot, cabernet, things that we hear of most of the time. But all of these varieties have a temperature threshold that they grow best in. Some varieties Page 2 of 9
do better in cooler climates and some do better where there is a longer growing season and a warmer climate. Dr. Greg Jones several years ago came out with this basic chart that gave an overview about how some of the grapes grow. But in general if you have more northern climates or higher altitude with a shorter growing season, white wines will grow better. But if you are in a warmer climate with a longer growing season you have the ability to grow red wines that have a more full body like a zinfandel, cabernet or sangiovese. There is an alternative though to growing these European varieties for wine. In the Eastern US and Midwest there are a lot of hybrid varieties that are grown and make wine. So they have baco noir and other varieties that would be great for you to try as a back yard grower. Slide 11 When you decide to obtain materials for planting, it is very important to remember that you are in an environment that is surrounded by commercial grapes. We want to protect our commercial industry and we do not want to bring in any diseases or pests. Furthermore, you do not want to invest your time or years of caring for a plant for it to simply to have a virus that was brought in with it. So, there is a service called the Northwest Grape Foundation Service and their website is listed here. And they provide nurseries with certified disease free plant material. Then the nurseries propagate this material and sell it to customers. So when you want to go to a local nursery, you can find a nursery that sells certified disease free plants by looking on the Northwest Grape Foundation Service website. Or alternatively, you can ask your nursery if their plants are certified and disease free. Typically, large chain growers, or large store commercial growers may not know that. But if you go to a smaller nursery that is more integrated or intimate with their nursery and supplier, they will know whether their plants are certified and disease free. Slide 12 So now, let s get into the actual grape vine. Here are some terms that you will have to know as we go further into this presentation. Starting from the ground up: there is a trunk which is the main part that carries the grape up, then as you come out there are cordons and the annual growth becomes shoots or canes. Slide 13 So when you want to start with your plant, you have your little plant that you bought certified disease free from a great nursery, you want to find a place in your yard that is not too cold. And remember, it has adequate air drainage and has full sun. I wouldn t worry too much if you had a north-south row. You hear that a lot from people planting grapes. But as a backyard grape grower you might be growing this on an arbor, you might have it along a fence; you don t have so many of these options. And I think that because you are not going to sell this product, do what works best for your backyard. You must trellis this, so as I said, you find an arbor or you create a trellis, or you find a Page 3 of 9
fence that it can run along which is an already made trellis. You will want to dig a hole that is big enough for the roots. So that is usually 10-14 deep and at least twice as wide as the diameter of the plant. So once you get this, you will want to prune it back to 2-3 buds of the strongest cane. And then you need six to eight feet between plants, and if you are going to plant rows, you need six to ten feet between rows. Slide 14 Okay, so the first summer, after you planted it, the first summer the idea is to let the main cordon grow, grow, and grow. The idea is to get the grape as big as it can before you put on fruit. So you want to actually remove any fruit that you may get and any low lateral shoots that are growing. So you want the main cordon to grow as far and as tall on the trellis as possible. So in the next three slides we are going to talk about weak growth, moderate growth, or vigorous growth. So you need to determine how well your plant grew in this first summer in order to know what to do after that. Slide 15 So in your first summer it grew, grew, grew and now it comes to February or March which was your first winter and you want to prune in between February and March. So you want to remove all of the laterals and all of the suckers and I will show you pictures of these. And the more vigorous the growth in any of the pruning from the first winter, second winter, and on the more vigorous the growth that you have it means the more buds that can remain. And the buds, if you remember from any plant biology, the buds are going to produce either the fruit or more leaves. So if you have a very strong plant that grows very strong you can support more new growth therefore leaving more buds. But if you are in a spot that you planted too late, it is under fertilized, you are getting weaker growth, don t stress the grape by making it grow even more. Remove more buds the weaker the growth. Slide 16 Okay, let s now look at some pictorial examples of weak, moderate, and vigorous growth and what that means. So here we see a grape vine that is growing and the line on the top would be the top trellis wire. And after the first summer that you planted it, and said grow, grow, grow little grape say it only grew half way to the trellis wire. That wasn t a lot of growth for what a grape can do. So what you really need to focus on is pruning it back and letting that strongest cane and cordon grow again and it will be very strong for your second summer. Slide 17 So now, let s assume that you got moderate growth. Which means, in the summer, your grape which is shown on the left grew pretty tall and grew all the way to the top cordon wire and maybe a little bit over one way or the other. What you want to do in the winter Page 4 of 9
is tie your grape to the cordon wire and remove any laterals that are on the side and you can cut off any growth that may have been moving to one side. Slide 18 So now, let s assume that you had a very happy grape that grew very vigorously. In that first summer it grew all the way to the top trellis wire far long the top trellis wire, either on one side or both sides if you split it. What you want to do there is come winter prune again and remove all the laterals down the side. And then you want to prune it back to just five or six buds if you are doing a unilateral training or three to four buds on each side if you are going to go both ways from your trunk. Slide 19 Break Time Slide 20 Now in the second summer, if you had moderate to vigorous growth, meaning that you reached your top trellis wire in the first growing season, you can carry out a very light crop. Grapes will tend to over set because if you were a grape your philosophy is to produce lots of fruit so that your seeds are spread. We don t want that to happen, what we want to focus on is growing a strong, healthy plant. And a grape can either put energy into growing strong healthy roots and a trunk or lots of fruit. So what you really want to focus on so that the plant is strong and resistant to diseases and for it to be very cold hardy, is for the second year if you are going to carry a crop, don t worry about cutting off fruit so that you have a very light crop. You really need to focus on the first year and second year on getting a strong and healthy plant. So again, if you have moderate to vigorous growth, you can carry a light crop but you may have to trim or remove some of the fruit so that you will attain a light crop because it will likely overset. So if you had weak growth, don t allow any fruit to develop because you really want to focus in on all the vegetative growth. So remove all fruit in the second summer if you had weak growth. And through the summer you still want to remove all laterals that may grow or suckers that may grow from the ground. Slide 21 So again, here are some pictures. You may had weak growth the first growing summer if this was you. For the second summer, remember that we trimmed it all the way back, almost to the beginning, or the ground level. And in the second summer, because we focused in on getting a strong shoot we get good growth that comes all the way up to the trellis wire. Slide 22 In moderate growth you will see new leaves and a very light crop and vigorous growth. Page 5 of 9
Slide 23 You will see lots of upright shoots and branching everywhere. Slide 24 So now again we are onto our second winter and we are going to prune again in February to March. And we prune a little bit later just to see how the plants have done through the winter. Again, you will remove any laterals and any suckers that grow from the ground. And again, the more vigorous the growth of the grapevine the more buds that you are allowed to carry. Slide 25 So, remember that weak vine that started to get to the top trellis wire you can now leave five to six buds if you are growing unilaterally or three to four buds when you prune it back. And these bud count numbers are not precise; use them as rough estimates or rough guides. Slide 26 So if you are going to do moderate growth, if you had moderate growth, you can leave six buds on a bilateral cordon. So in general, you leave twelve buds total. Slide 27 And if you had very vigorous growth, you can say that I am going to leave a total of sixteen buds, eight on each side. If you want to leave more, that is fine. If you want to cut it back because it doesn t fit the space in the garden, that is okay also. Slide 28 Okay, so year three- this is our investment. From year three and beyond you should be able to have normal growth and normal fruit. So you will not, in general, have to remove any fruit anymore. Again, from February to March you will want to prune your shoots and you will want to leave on the plant roughly sixty to eighty total buds per plant. So what that means is three to five buds per shoot. Slide 29 Okay, so let s go into pruning in more detail. This is a picture of a grapevine that has more downward growth. This would be an example of one of the American varieties like Concord. And the top is what it would look like in February or March when you haven t pruned and the bottom picture is after you have pruned. Page 6 of 9
Slide 30 This is more of a European variety, so our typical wine grape variety. So again, remember that I talked about the upright growth. So before pruning you will see the picture on the left and then after pruning, when I say that each one gets three to five buds, you will see on the after pruning that you will get on the left, two to three buds, but if you wanted a longer spur or a longer shoot, you can leave four to six buds. So anywhere in that three to five bud range would be adequate for a back yard grape. Slide 31 Okay, so in pruning we maybe want to start with a pre-prune. And the pre-prune will help us get down to looking at our individual shoots. But sometimes grapes grow pretty wild in there; shoots are inter-tangled so you can pre-prune a little bit just to get the mass of plant material out of the way. It depends on how it grew for you. So you want to start by getting rid of any shoots that originate below the cordon wire. Anything that grows down towards the ground under the cordon wire is not going to get good light. So remove any shoots that will grow under the cordon wire. Keep shoots a fist width apart and cut three to five buds per shoot. And lastly, we are going to remove any antlers, as the years go by we get bigger and bigger antlers. And I will pictorially show you what this means. Slide 32 So now let s show you through pictures what some of those steps were. If you have lots of growth where the shoots are tangled in with each other, the pre-prune is just removing some of that mass of leaf and shoot material. And the second easy step is to go along the cordon and remove any shoots that are growing directly straight down underneath the cordon. And the third step to keep in mind is when you are actually removing shoots is to keep a fist s width between shoots that are growing off the cordon. And the fourth step, remember, is to trim the shoots that are growing at the top of the cordon, trim them back three to five buds per shoot. Slide 33 And the antlers are what happen when you start to grow grapes for many years. The idea behind removing antlers is that the nutrients for a grape come from up through the roots, up through the trunk, and along the cordon. If you start to get these growths where you have new spur that is shown on the left and it grows from second year wood to third year wood will eventually in five to six years, what you will get is further and further away from the main cordon. What that means is that the plant will have to transport those nutrients all the way from the cordon to further and further away. The best grapes grow when the shoots are close to the cordon. So every few years or so you will have to go through and remove some of these big antlers as we call them, where the plants have gone through further and further away from the cordon. New Page 7 of 9
shoots and new buds will break on the cordon to accommodate for some of this removal. Slide 34 Okay, so when your grapes are growing fine and they are established and even when you are getting them established you want to know how to fertilize them. So the best way to fertilize them is spread this fertilizer, you are going to have an annual fertilizer rate and you want to spread it over three times through the spring to midsummer. And basically what I tell backyard growers is that when you start to get bud swell to before the grapes start to turn in color, and that is called veraison; somewhere in that time get three equal spacing of fertilizer. And in a commercial vineyard we would say that you need based on your soil tests, anywhere from sixty to one hundred pounds of nitrogen. So in that example in commercial, you would take three shots of twenty pounds of nitrogen if you are only putting sixty pounds of nitrogen on. For backyard growers, what you want is about three and half pounds. If you were going to get a mixed fertilizer of 10N-10P-10K, then you basically want to spread that three and half pounds, so maybe one pound, one pound, one pound, three times over that spring and early summer before the grapes get color. After that you don t want to fertilize later in the fall because the fertilizer going through the system isn t going to be absorbed by the grapes as well, but you can also hinder the grapevine from going into dormancy and become more cold hardy for the winter. So think about fertilization only from early spring to early summer. Slide 35 Besides nitrogen, phosphorus and potassium you also need some micronutrients like zinc and boron. But many healthy soils that back yard growers have because they use compost or other micronutrients in their soil, most of the time this is taken up easily through their natural systems. Compost is a great alternative especially in back yards but if you are growing a very, very heavy crop you have to understand that compost doesn t always release all of its nitrogen in one year. So it is a slow release. So if you are growing a very heavy crop, make sure that you add other types of fertilizer until you have a very long-term set of adding compost to your soil. Slide 36 There are numerous pests and diseases that attack grapes. I am only going to cover this very briefly in this one slide just to give you an idea of some of the things to be aware of. If you choose to plant an American native variety such as a Concord or Niagara, you will have very little to worry about. These grapes are very wonderful because they are very insect and disease resistant especially in the Western United States. If you choose to plant a wine grape variety you can have numerous insects or diseases. The first thing is to get the insect identified. Knowing what insect to have is very important in knowing how to control it. And when it comes to control there are a few choices that you have as homeowners. You typically have to buy something that is off Page 8 of 9
the shelf from a major retailer. But you do have some choices in that shelf product. You can start with a chemical that would be registered on organics, such as a Spinosad. It is a little bit safer and nicer especially where you are around the home. You alternatively go to a stronger chemical such as malathion which has control or kill on almost all insects but it is also a little bit more toxic to the user in the end. So there are a lot of cultural controls that you can also practice such as having an open canopy, planting companion plants that attract lots of lady bugs and lace wings which are very good predators, and also we have very small predators which we cannot see such as predatory mites. So things that you can encourage and have less disruption of the system can sometimes keep your insect population under control. For diseases, usually we see them late in the summer such as powdery mildew or white fuzz that comes onto your grapes or leaves. However, control of powdery mildew occurs long before we can see it. So control occurs before bud break to early spring. And there are a lot of cultural things too that can help you with diseases. So have an open canopy if you have wine grapes, meaning that you allow good air movement to flow through. If you are going to water with overhead irrigation, water very early in the morning so that the water has time to evaporate and dry on the leaves before you get a really good puddle in a place where powdery mildew will build up and grow. So, again there are numerous pests and numerous insects that could occur on your wine grapes but the first thing to do is possibly plant varieties that you won t have to worry about this with, but if you choose a different variety, first get your insects identified, start with cultural control that can minimize your insects and diseases and then choose products that will accommodate your philosophies are and how you want to treat the insects in your home. Slide 37 So, with all of this information, hopefully you will have good establishment, good growth, good pruning, good fertility and good pest management so that in the end you get these wonderful grapes to enjoy. Page 9 of 9