Days to germination: Grapes are started from seedlings
Days to harvest: 3 years
Light requirements: Full sun
Water requirements: Regular watering
Soil: Loose and well-drained but fertile
Container: Yes, with pruning
Grapes can be grown for eating, or for making wine. Not all varieties are the same so you should decide what you want to do with your fruit before you start to plant. Grapes for eating (usually referred to as table grapes) are much sweeter than wine grapes.
And then there are green, red or purple grapes to choose from as well. There are literally several hundred grape varieties to choose from.
Grapes are usually eaten raw, juiced or made into wine. They are not a fruit used in cooked foods very frequently. You can get vitamins A, C and several B vitamins in grapes. They also have calcium, and a mix of antioxidants as well.
Grape plants are not usually started by seed for the home gardener, so you will need a cutting or seedling to start your plants.
Grapes have very deep roots, so when you are digging a hole for your seedlings, you should dig down at least 3 feet in order to loosen the soil underneath the actual hole.
Most grapes are not self-fertile, so you should plan on growing 2 or 3 separate vines in order for them to produce any fruit. Choose a sunny location where you have space to put up wires to train the vines for support (see growing section for more on pruning).
Having your grapes on a trellis or other kind of support is a must with grapes. Rather than letting the vines grow up a trellis like runner beans, the traditional way to support grapes is with 2 or 3 horizontal wires. You then train or tie the vines sideways along the wires. The specific way to get your vines laid out will vary, depending on the way you are pruning your grapes.
Heavy pruning is also a necessary part of growing grapes. It may be hard to cut away large portions of your precious plants, but you want the vines to grow large grapes with good flavor. Allowing the plant to produce too many grapes will result in very small fruit with poor taste.
Pruning grapes can be a bit complicated, and if you can get a demonstration or explanation from the nursery where you get your seedlings, that may help. The easiest method is called the Kniffen System. You’ll need two 8 foot stakes, set 10 feet apart with your grape seedling in the center. String a wire between them at 3 feet high and 6 feet high. Let your plant grow during the first year and choose the strongest vine to be your future “trunk”. Tie that vine to both wires, training to grow upright.
During the second year, choose 4 good vines growing from that central trunk, and train them along the wires (2 along the lower wire, and 2 on the higher one). Prune away all other vines by the end of the year. Your framework is now in place.
In the third year, you will get start to get a fruit harvest on the 4 main vines you have left on your plant. But you will want to replace these vines by next year to get another season of fruit. So let 4 more vines grow, and at the end of the year, prune away your original 4, and tie the new ones to your support to fruit next year.
It seems complicated but once you get the rhythm of pruning, it will just become another regular garden chore. Pruning is usually done in late fall, around November.
Though they have fairly deep roots, as long as you keep a grape vine well pruned, it can be kept within the confines of a pot. You won’t likely get a huge crop, but a container grape vine can produce you some grapes if you care for it well.
You will still need more than one plant in order for proper pollination to take place, so you can have grapes. There are some “ornamental” grape vines sold as container plants because of their lush vines. When buying your seedlings, make sure you are getting a plant that will produce fruit.
Your plants will still need support, which can be a bit awkward to build around a pot. Any kind of trellis will work but your grapes will grow better if you can support them horizontally rather than vertically.
Pests and Diseases
One of the most important problems you may have to deal with is powdery mildew. You will see what looks like a white dusting on the leaves, usually the newer small leaves. Mature leaves are usually strong enough to resist the fungus. If unchecked, it can attack your fruit as well causing grapes to turn gray or to split open. Either way, the fruit is ruined.
To help prevent its spread, take care to water your grape plants at soil level and don’t soak the leaves. Mildew likes moisture, and wet leaves make it worse. You can pick off effected leaves at first to control it, but if that doesn’t stop it you will want to treat your plants with a fungicide treatment.
Grapes can also be subject to damage by grape leafhoppers. They’re fairly small insects with yellow markings, with their wings folded over their backs. They drink the juices from the plants leaves, and in large numbers they will cause your vine’s leaves to curl and wither. A typical dose of insecticide spray can usually take care of them.
Harvest and Storage
You can’t judge the ripeness of a grape from its color. They won’t be ready to pick for possibly weeks after they turn their final color, so keep track of the official maturity times for your particular varieties of grapes, and periodically taste them yourself to see where they’re at.
The fruit grows in clusters, and you should harvest the entire cluster rather than plucking each individual grape off the vine. Use a pair of clippers to cut the bunch free.
Fresh grapes store best in the refrigerator, not sealed in a container. A mesh bag or perforated plastic bag works best for grapes and they will keep for about a week this way. Grapes keep better if left on their stems until you want to use them.
Grapes are one of the few fruits that can be frozen, and that retains its shape and texture once thawed. Pull your grapes off their stems, and just freeze them whole.