Originally published June 22, 2024 in the Yakima Herald-Republic
by Claudia Steen
Growing table grapes around your home is a bit of a challenge, however, they can add to the décor and when you taste those grapes as they become ripe, the result is worth the effort.
What are some of the characteristics that are important to growing grapes: Grapes like full sun and need 150+ frost-free days (which we have in the Yakima valley). They grow best in a South or Southwest exposure and require a well-drained sandy loom soil. If rocks are present in the soil, it is OK. As you prepare the soil be sure to remove any weeds.
You can buy grape plants at a local nursery as: bare root plants or grafted plants in container pots.
There are many varieties of Table Grapes to choose from:
- White varieties include Himrod, Interlaken, Niagara, Perlet, Lakemont, and Thompson.
- Red varieties include Concord, Flame, Crimson, Reliance, Canadice, Suffolk Red, Catawba and Black Manuka (my personal favorite). They are either Labrusca or Vinifera varieties of grapes.
When planting bare root grapes, it is best to plant them in March-April. Be sure and soak the roots in water before planting. Then spread the roots over the base of hole and plant 10-14 ” deep. If they are grafted and in containers keep the union above the soil and plant in May or June. Place the plants 4-8 feet apart from each other and firm the soil around the plant. It is also best to place a stake next to the plant so the vines can be trained up easily. Dig a small indentation around the plant for water to settle and it is best to water deeply every 7-10 days when newly planted. This will allow the root base to develop. Fertilize with a weak balanced nitrogen in early spring on new plants only and be sure to weed around each plant.
As the new grape plants are growing it is best to harden off these plants in September by water stressing. You will see the leaves change color & drop off or defoliate. Give them a thorough watering in October and if bare dirt, you can place mulch around each new plants to over winter. An easier method is to place fabric cloth & medium size rocks around the base of each plant. The Labrusca varieties are cold tolerant to minus 20 degrees F, and the Vinifera varieties tolerant to minus 10 F.
Drip Irrigation is best for watering with emitters placed on each side of the plant. It is important to have an in-line filter for irrigation water. You can also use a soaker hose if house water is used but avoid an overhead sprinkler system!
Grape plants require pruning. The objective of pruning is that this is important to establish and maintain vines in a desired shape, distribute the proper amount of wood over the vine in order to yield high quality grapes, and to regulate the amount of crop to lessen the need for thinning as grapes won’t ripen if over cropped. Grapes are produced from spurs that develop from one year old wood.
When pruning the 2nd year, it is best to prune when dormant (February or March), prune back to two bud spurs, make clean diagonal cuts above the buds and prune before the buds’ swell. Also, the 2nd year be sure to secure 1-2 strong vines to the stake with ties every 8-12 inches for the trunk and allow the vines to grow out onto the main wire or cordon & tie them at the end to secure them.
Trellis systems are best put in before planting, set treated end posts deep into the ground and secure #10-12 high tinsel wires or other cordons of metal or wood. You can also use a fence, a stone wall or other natural objects as well if you have very few plants. Another attractive method is to provide support using a freestanding Grape Arbor. Although it requires more attention to pruning and training canes onto the support.
Another alternative to a trellis system is to use the pergola over an existing patio or deck. Train 1-2 or 3 vines up each post. The vines will grow up the pergola so assure the vines are attached to the support as they grow. You can remove all the lateral growth but retain the leaves. When the trunks reach the top of the pergola you can have each of the branches attached to the cross beams. As the branches grow this will provide shade to the deck or patio as well as being able to see the beautiful grapes as they grow and mature when you are relaxing on the deck or patio. If you planted Red Variety grapes, they start off green and as they grow they go through varasion where they turn from green to purple.
Each year remove any suckers at base of the plant BUT if the trunk(s) die new growth can occur from these plant base suckers.
Pruning the 3rd year, leave 4-6 renewal spurs evenly spaced on the cordon and cut to 2-3 buds on each spur where fruit production will occur. Also ensure any green growth from the trunk is removed. In time the trunks will produce a rough bark which adds to the appearance.
Another aspect of growing table grapes is bird control with many methods available, that depend on the size of the planting: in a larger vineyard the choices include plastic owls, glitter tape, distress calls, Zon guns and Kestrel nests. But if a smaller planting is around your home a trick is to net the canopy as the grapes are starting to turn color. However, if there is one small plant, place onto each cluster of grapes knee high panty hose when mid-size and still green. The panty hose will expand as the grapes grow. Vertebrate pests include Starlings and Robins who can strip the plant of all your precious berries.
One important disease of grapes is Powdery Mildew, this is a fungus where spores are carried by the wind. They have a fine web of white threads on older leaves and then go onto the fruit. Therefore, it is best to keep the canopy open for good air circulation and using a drip irrigation system is important. There is a chemical control using sulfur spray as a preventative. The result of all your care is that you will be eating amazingly flavorful grapes when they become ripe and if you harvest lots of grapes, it is fun sharing them with family and friends.
And again, if there is an abundance of grapes and you have a food dryer. Place the individual grapes on the screens and this will produce amazing raisins that can be eaten as a healthy snack.
ENJOY.