Idaho’s high desert climate with warm days and cool nights produces grapes with excellent sugar balance. If you are looking for the **best grapes to grow in idaho**, you need varieties that handle cold winters and short growing seasons. This guide covers the top choices for home growers and small vineyards.
Idaho is not just for potatoes. The Snake River Valley and other regions have become known for quality wine grapes. But you can also grow table grapes for eating fresh. The key is picking the right cultivar for your specific location.
Best Grapes To Grow In Idaho
The best grapes for Idaho fall into two main groups: wine grapes and table grapes. Wine grapes thrive in the arid climate with low disease pressure. Table grapes need more heat but some varieties still work well here.
Below is a breakdown of the top performing varieties. Each one has been tested in Idaho’s unique conditions.
Wine Grapes For Idaho
Idaho’s wine industry focuses on cool-climate varieties. These grapes ripen fully before the first frost. They also develop complex flavors from the big temperature swings between day and night.
- Riesling – This is the most planted white grape in Idaho. It handles cold down to -10°F. The wines are crisp with apple and citrus notes.
- Chardonnay – Grows well in the Snake River Valley. Needs a site with good air drainage to avoid spring frosts.
- Cabernet Franc – More cold hardy than Cabernet Sauvignon. Produces medium-bodied red wines with herbal flavors.
- Merlot – Works in warmer microclimates like the western part of the state. Ripens earlier than Cabernet Sauvignon.
- Syrah – Performs well in southern Idaho’s heat. Needs careful site selection to avoid winter injury.
Table Grapes For Idaho
For eating fresh, you need seedless varieties that ripen before October. Here are the most reliable choices.
- Concord – Classic purple grape for juice and jelly. Very cold hardy. Ripens in late September.
- Reliance – Red seedless grape with sweet flavor. Survives -20°F. Ripens in early September.
- Canadice – Red seedless grape. Compact clusters. Good for small spaces. Ripens in late August.
- Himrod – White seedless grape. Very sweet. Needs a warm spot. Ripens in early September.
- Venus – Blue-black seedless grape. Disease resistant. Ripens in mid-September.
Climate And Site Considerations
Idaho’s climate varies a lot from north to south. The northern panhandle is cooler and wetter. Southern Idaho is high desert with less than 12 inches of rain per year.
Most grape growing happens in the south. The Snake River Valley has elevations from 2,000 to 3,500 feet. This means warm days and cool nights. The low humidity reduces fungal diseases.
Winter cold is the biggest challenge. Temperatures can drop to -20°F in some areas. You need varieties that can survive these extremes. Site selection matters a lot.
Choosing The Right Site
Grapes need full sun. At least 8 hours of direct sunlight per day. They also need well-drained soil. Standing water will kill the roots.
A south-facing slope is ideal. It warms up faster in spring and stays warmer in fall. This helps avoid frost damage. It also improves ripening.
Avoid low spots where cold air settles. These areas get frost more often. Plant on a slope or hilltop if possible.
Soil Preparation
Idaho soils vary from sandy loam to clay. Grapes prefer a pH between 5.5 and 7.0. Test your soil before planting.
Add organic matter if your soil is heavy clay. This improves drainage. If your soil is sandy, add compost to hold moisture.
Grapes do not need rich soil. In fact, overly fertile soil produces too much foliage and not enough fruit. Moderate fertility is best.
Planting And Care
Plant grapevines in early spring after the last frost. Bare-root plants are common. Soak the roots in water for a few hours before planting.
Dig a hole deep enough to spread the roots out. Place the vine at the same depth it was in the nursery. Fill the hole with soil and water well.
Space vines 6 to 8 feet apart. Rows should be 8 to 10 feet apart. This gives enough room for growth and air circulation.
Watering
Grapes need regular water during the first year. After that, they are fairly drought tolerant. But they still need water during dry spells.
Drip irrigation is best. It puts water right at the roots. It also keeps the leaves dry, which reduces disease.
Water deeply once a week during summer. Adjust based on rainfall. Overwatering can cause root rot.
Fertilizing
Grapes need nitrogen, but not too much. Apply a balanced fertilizer in early spring. Use 10-10-10 at a rate of 1 pound per 100 square feet.
Do not fertilize after midsummer. This encourages new growth that can be damaged by winter cold.
Test your soil every few years. Adjust nutrients based on the results.
Pruning
Pruning is essential for good fruit production. Grapes produce fruit on one-year-old wood. You need to remove old wood to encourage new growth.
Prune in late winter while the vines are dormant. Remove dead or damaged canes. Leave 2 to 4 buds on each spur.
There are two main pruning systems: cane pruning and spur pruning. Cane pruning is common for wine grapes. Spur pruning works for table grapes.
Pest And Disease Management
Idaho’s dry climate helps reduce many grape diseases. But you still need to watch for common problems.
Common Pests
- Birds – They love ripe grapes. Use netting to protect your crop.
- Wasps – They damage ripe fruit. Traps can help reduce their numbers.
- Aphids – They suck sap from leaves. Insecticidal soap works well.
- Spider mites – They cause leaves to turn yellow. Keep dust down and use miticides if needed.
Common Diseases
- Powdery mildew – Shows as white powder on leaves. Use sulfur sprays to prevent it.
- Downy mildew – Causes yellow spots on leaves. More common in wet years. Copper sprays help.
- Black rot – Causes fruit to shrivel. Remove infected fruit and use fungicides.
- Botrytis – Also called gray mold. Good air circulation helps prevent it.
Harvesting And Storage
Harvest time depends on the variety and the weather. Most grapes ripen from late August to October. Taste the fruit to check for sweetness.
Table grapes should be fully colored and sweet. Wine grapes need the right sugar and acid balance. Use a refractometer to measure sugar levels.
Cut the clusters with pruning shears. Handle them gently to avoid bruising. Store table grapes in the refrigerator. They will keep for several weeks.
Wine grapes should be processed right away. They do not store well once picked.
Winter Protection
Idaho winters can be harsh. Even cold-hardy varieties may need protection in severe years.
Mulch around the base of the vine with straw or wood chips. This insulates the roots. For extra protection, mound soil over the graft union.
In very cold areas, you can bury the vines. Dig a trench next to the vine. Lay the vine down and cover it with soil. Uncover it in early spring.
Recommended Varieties By Region
Different parts of Idaho have different growing conditions. Here are the best choices for each region.
Southern Idaho (Snake River Valley)
- Riesling
- Chardonnay
- Cabernet Franc
- Merlot
- Syrah
- Concord
- Reliance
Northern Idaho (Panhandle)
- Concord
- Reliance
- Canadice
- Himrod
- Venus
- Frontenac (wine grape)
- Marquette (wine grape)
Central Idaho (Mountain Areas)
- Concord
- Reliance
- Canadice
- Frontenac
- Marquette
Frequently Asked Questions
What Are The Best Table Grapes To Grow In Idaho?
Reliance, Canadice, Himrod, and Venus are the best table grapes for Idaho. They are seedless, cold hardy, and ripen before frost.
Can I Grow Wine Grapes In Northern Idaho?
Yes, but you need cold-hardy varieties like Frontenac and Marquette. These grapes survive temperatures down to -30°F.
How Long Does It Take For Grapevines To Produce Fruit In Idaho?
Most grapevines start producing fruit in their third year. Full production comes in year four or five.
Do I Need To Cover My Grapevines In Winter?
In southern Idaho, most varieties do not need covering. In northern Idaho, covering or burying vines may be necessary in severe winters.
What Is The Best Soil For Growing Grapes In Idaho?
Well-drained sandy loam with a pH between 5.5 and 7.0 is ideal. Avoid heavy clay or poorly drained soils.
Final Tips For Success
Start with a small planting. Learn how grapes grow in your specific location. Expand after you get some experience.
Join a local grape growing group. The Idaho Wine Commission and local extension offices have good resources. Other growers can share tips that work in your area.
Be patient. Grapes take a few years to establish. But once they do, they can produce fruit for decades.
Idaho is a great place to grow grapes. The climate is perfect for many varieties. With the right choices and care, you can enjoy fresh grapes or make your own wine.
Remember to pick varieties that match your climate and site. The best grapes to grow in idaho are the ones that survive your winters and ripen before your first frost.
Happy planting and good luck with your vineyard.