Grapes are man’s oldest form of permanent agriculture and really have only one requirement for the backyard grower-full day long sun. (Of course a swampy condition or severe frost pocket eliminates most fruit.)
With a postage stamp size back yard it is possible to have a few varieties by head training them on a post (steel or wood) that stands about six feet above the ground. Start the new plant by allowing one shoot to grow from the plant-remove all others. Tie the new shoot to the post with a soft cloth at six to eight inch intervals. By removing all the side shoots as it grows (do not remove leaves) it will reach the top of the pole by mid summer. Pinch the vine at the top of the post leaving up to three side shoots near the top. Fish fertilizer should be used the first year to promote rapid growth. These canes or shoots at the top are allowed to hang down. No fruit will develop the first year. The following spring these shoots at the top should be shortened allowing about a total of four buds on them. Keep the main trunk bare. These buds will develop into canes that bear fruit. The new vine cannot support more than one bunch of grapes the fist year of bearing. Each year allow only the buds at the top to develop into fruiting canes. Buds that appear on the lower trunk should be rubbed off when they are the size of pencil erasers.
Production from head training will not equal methods used in the field, but is certainly an ideal option for the tiny backyard.
Avoid watering grapes after mid August (except first year plants) as watering will greatly delay fruit ripening.
The basic rule of thumb for pruning grapes (head pruning, spur pruning, arbor pruning, kniffen pruning etc.) is to remove at least 90 percent of the previous year’s growth.
Seedless grapes come in many colors and flavors. The two main considerations for Oregon are to get disease resistant varieties and varieties that ripen early to mid September. A vine on the south side of a building can ripen up to two weeks earlier due to reflected head. Hybrid grapes will do much better in Oregon than viniferous (California types).
The Challanger grape (from Missouri) was the best-liked grape of the HOS group that toured my vineyard last fall.
Some of the best grapes are not fully cold hardy with many cane dying out over winter.