The first step in growing grapes is to decide on what type of grape you want to go. Grapes generally come in three types: American grapes, which grow well in sunny places like California, European grapes, which grow well in Europe and in the northern US, and muscadines, which grow well in the southern US. Within each classification, there are many different cultivars. The other decision you must make in the beginning is whether to grow table grapes or wine grapes. You can ask your Extension agent what varieties of grapes grow best in your area.
Now you need to decide where to plant your grapevines. Grape vines will grow well on southern facing hill sides, but can grow any place that they get at least seven hours of sunshine. The land must also drain quickly as the roots will rot if they stay soggy. Make sure that other plants are removed before planting the grapevines. In the north, plant the grapevines in a sunny location facing the south to help them keep from freezing.
Grapes are picky about the soil they live in. They like sandy or rocky soil with a pH of just above 7.0. You can get a soil test kit from your local Extension office. Do a soil test to make sure your soil will support grape vines. You do not want to plant a bunch of grapes that die on you because the soil and pH are not to their liking. The soil test will also tell you just exactly what nutrients you need to add to your soil to help the grape vines grow well. Grapevines do not grow well in the presence of too many nutrients. You end up with beautiful vines and no grapes.
Before you plant your grapes, you need to construct a trellis for the vines to grow on. Most grapevines are trained to grow up a stake then along a wire. They form a T when they are properly trained to grow on the fence and then properly pruned so that there are two branches that go in opposite directions on the wire.
When you have decided what variety of grapes you are going to grow, you will need to purchase them. Get one year old grape vines during the winter while they are dormant. These are referred to as “bare-root” grapes because they are sold with no soil attached to the vine. You need to make sure they are healthy. If possible, get certified virus free canes. You also want canes that have an even root distribution and whose canes are symmetrical.
American and European grapes should be planted every six to ten feet. Muscadines should be planted every sixteen feet. Dig a trench and lay the grape vine’s roots in it. The vine should have three buds on it. Plant it deep enough that only the top bud is above ground. Then fill in the trench.
After planting your grapevines, water them in well. The first year, you need to water an inch a week. After the first year, when the grape vines are established, you will only need to water them when they start wilting. The most effective way of watering them is to spread drip irrigation throughout the orchard so that the water only comes out at the base of each vine. That way, it goes directly to the root and does not evaporate the way other ways of watering do.
The first year, you should prune off any branches that have fruit just before the fruit. This allows the grapevine to expend its energy growing and becoming established instead of producing grapes. It will also prevent the heavy grapes from breaking the vine. Pruning should be done when the grapevine is dormant. Otherwise it will bleed sap and that wastes needed nutrients.
Do not mulch around your grapevines. The mulch keeps the soil cool and grapevines like their roots to be warm. Grapevines are naturally hardy and rarely need to be sprayed with insecticides. They are vulnerable to the vine moth and to aphids. Aphids are eaten by ladybugs. You can buy ladybugs from some garden supply companies to let loose in your vineyard. If you let them, the ladybugs will eat the aphids for you. If you must do something about the aphids, insecticidal soap is a reasonably safe insecticide to use if you follow the directions on the label.
The vine moth (Lobesia botrana) can devastate your vineyard. First found in the United States in 2009, it is spreading fast. Originally from Europe, it is now found on almost every continent. In the first generation, larvae chew on the flower clusters. Second generation larvae feed on green berries. Third generation larvae feed inside berries and within bunches, which they contaminate with their excrement. Low toxicity pesticides target the second generation of this pest. These include insect growth regulators, spinosyns, and Bacillus thuringiensis.
A common disease in the south is Pierce's disease. It is a fungal infection that blocks the flow of water up the grapevine and nutrients down the grape vine. Your Extension agent can tell you if you need to purchase Pierce resistant grape vines. These are vines that have a resistant rootstock grafted on them but have a good tasting variety on top of the rootstock and will produce the desired grape without being infected with Pierce’s disease.
Keep the area around your grapevines weeded to prevent the weeds from stealing needed nutrients from your grapevines. You may also have to cover your vines with bird netting to keep them from damaging and eating your grapes.
Your vines will not start producing good grapes for one to three years. Before you harvest your grapes, take one grape from the bottom of several of the clusters and taste it. If the grapes are sweet, they are ready to pick. Grapes do not continue to ripen once picked, so make sure you do not pick the grapes before they are ripe.