About Grapes
Table Grapes
Grapes grow well in our climate. As of 2025 we were growing only table grapes in the Fruit Garden.The table grape varieties we grow were tested in trials here at the Mt. Vernon station and found to do consistently well, ripening early enough in our maritime climate.
Wine Grapes
The Mt. Vernon station has also done research on growing wine grapes in Western Washington. Wine grapes have been bred for juice, and generally have more seeds and higher sugar levels than table grapes. The wine grape trials have shown that there are many early ripening cultivars and early ripening inducing rootstocks that produce high quality red and white wines in our area.
Growing Winegrapes in Maritime Western Washington – WSU (PDF)
How to Grow Grapes
Grapes are reasonably easy to propagate by rooting (Feb.-Mar.) dormant cuttings of the first 1 to 2 feet of last year’s vine growth. The vines in the Garden are not grafted, but grow on their own rootstock. We grow them using two trellising systems: arbor (photo1), and a head-trained, spur-pruned vertical pole system that turns the vine into a weeping bush (photo2). Both can be successfully maintained for many years through annual pruning. The arbor system is more productive per vine, but the vertical pole is a great way to grow grapes in a limited space.
Two other systems used by wine grape growers: horizontal cordon spur pruning systems and cane pruning systems, on a multi-wire trellis, can also be applied to table grapes on vines planted (4 to 6 feet apart) in rows at least 8 feet apart. Spur pruned grapes may also be trained in a variety of creative ways on chain link fences.
In all cases, annual maintenance pruning is key. Fruit grows each year approximately 6 to 18 inches away from buds that developed on the previous year’s growth. Left unpruned, vines will grow longer and become more tangled (fruit more difficult to access). With annual pruning, the vines remain untangled and the fruit is produced in a consistent location each year. We spur-prune our grapes in the dormant season (Dec-February), cutting back last year’s growth to the two to four buds closest to the permanent fruiting spurs on each cordon. When cordons become unproductive, new cordons can be grown and phased in over a period of a few years.
Fruit is harvested September-October. We generally have few problems with disease on our grapes beyond a form of mildew that can appear on Einset and Vanessa in late-summer and can make the fruit inedible. Spray programs exist to control this kind of fungus, but we are currently trying a method of thinning new growth and foliage (to allow more air and light) in July as a cultural control.
