Planting grape seedlings successfully starts with careful attention to seeds as they sprout and extends to outdoor plot selection, seedling spacing, and vine cultivation. Choosing seeds is usually the first step. From there, the seeds must be germinated and nurtured in a controlled environment in order to induce sprouts. New shoots are only the beginning, however. In order to thrive, the seedlings must be planted in outdoor plots where their roots will be able to expand and take hold.
Depending on what types of grapes you hope to grow, choosing your seeds may be one of the most important parts of your seedling planting experience. There are a great many grape varieties, ranging from large fruits with sweet juices to the small, bitter offshoots commonly used in wine making. Seeds are available in many nurseries or, in most cases, you can simply remove seeds from an existing fruit in order to reproduce it.
Commercially cultivated grapes are usually an exception. Grapes that are professionally grown for snacking are often hybrids that have been optimized for certain characteristics. Their seeds will sprout and grow, but the fruits only rarely emulate the parent. Commercial seeds usually produce smaller, more bitter grapes than those sold in stores.
Seed germination is the next step. Most grape seeds must experience a period of cold dormancy before they will sprout. This normally happens in nature during the winter months, but can be artificially triggered by keeping seeds in the refrigerator or in another dark, cool area. Keep the seeds moist and wait for small sprouts to emerge. Germination can take anywhere from two to six weeks.
Once the seeds have germinated, they must be planted in rich soil and kept in a warm area, preferably in direct sunlight. Growing seedlings can take an additional two to four weeks, depending on the conditions. It is usually best to start by planting seedlings in shallow soil in a small container, so that they do not have to struggle far to break the surface. Keeping the soil constantly moist will help accelerate the process.
It is usually best to keep grape seedlings indoors until they have reached substantial height, typically at least six inches (about 15 cm). They need to be hardy enough to survive transplantation, and their root systems must be strong in order to adapt to an outdoor, in-ground environment. Transplanting seedlings is usually best in the early spring, after the last frost. Look for a plot of land in direct sunlight for best results.
Grapes tend to grow best on hillsides with southern exposures, where the sun is strongest in the summertime and where excess water naturally drains away. Planting grape seedlings in lowlands can lead to root rot. Once the plants are strong enough to be outside, their roots should soon adapt to even the driest soils. The plants will learn to store water internally, and excess moisture can be fatal.
Proper plant spacing is also crucial for root health. Ideally, grape seedlings should be placed anywhere from 3 to 6 feet (about 1 to 2 m) apart. This is much farther than most fruit seedlings and vegetable seedlings require, but will allow the grape seedlings' roots to spread, and will leave enough space for vines to develop without crowding each other out.
Once the seedlings have taken off, you must train the tendrils that shoot forth from the young leaves. Start by tying the seedlings to a stake that can be linked to a horizontal wire or dowel system in future seasons. As soon as tendrils emerge, loosely tie them to the horizontal axis so that they will grow out, as well as up.