Strawberry in Zone 7A — Mountain West

Strawberries, bursting with sweetness intensified by our cool Mountain nights, are a rewarding addition to any high-altitude garden. Freshly picked berries are far superior to anything you'll find in stores, and growing your own allows for unique varieties perfectly suited to our intense sun. Plus, the satisfaction of a successful harvest in our short season is unmatched.

While high altitude, intense UV, and alkaline soil present challenges, careful timing ensures a bountiful harvest. Our dry climate actually helps minimize some common diseases. With a growing season of around 173 days, strawberries fit perfectly into our Mountain West gardens.

Transplant your strawberry starts outdoors from early to late April, once the danger of hard frost has passed. It's best to buy bare-root plants or potted starts from a local nursery in spring. Growing from seed is a long, drawn-out process in our short season.

Before planting, harden off your seedlings by gradually exposing them to the outdoors for about a week. Start with a few hours of shade and increase the time and sun exposure each day. Space plants 12-18 inches apart to allow for good air circulation.

Keep an eye on the weather forecast, as late spring snow or hail is not uncommon in the Mountain West. Be prepared to cover your new transplants if necessary to protect them from unexpected cold snaps.

Strawberries need consistent moisture, especially during their fruiting period. Our dry Mountain climate means you'll need to be diligent with watering, but avoid overwatering, which can lead to problems. Drip irrigation is ideal, delivering water directly to the roots and keeping the foliage dry, reducing the risk of fungal diseases that thrive in wet conditions.

During the active growing season (late spring through summer), aim for about 1 inch of water per week, either from rainfall or irrigation. Use the finger test: stick your finger about 2 inches into the soil near the base of the plant. If it feels dry, it's time to water. Water deeply at the base of the plants, avoiding overhead watering as much as possible. Low humidity here helps, but wet foliage is still risky.

Signs of underwatering include wilting leaves and dry, crumbly soil. Overwatering can lead to yellowing leaves and root rot. Mulch heavily around your strawberry plants with straw or wood chips to help retain moisture in our dry air, suppress weeds, and keep the berries clean.

Strawberry pruning is minimal but important for maintaining healthy plants and maximizing fruit production. The main task is to remove runners, those long stems that sprout from the main plant. Unless you want to propagate new plants, cut these off to direct the plant's energy towards fruit production.

Remove runners anytime you see them throughout the growing season. For June-bearing varieties, renovate the bed after harvest by mowing or cutting back the foliage to about an inch above the crown. This encourages new growth for the following year.

As the first frost approaches in early October, don't prune. Leave the foliage in place to insulate the crown during the winter. You can remove any dead or damaged leaves in the spring.

Your first strawberry harvest in Zone 7A should arrive from early July through mid August, about 90 days after transplanting. Look for berries that are fully red with no white shoulders and have a fragrant aroma. These are key signs of ripeness.

Gently pick the berries with the green cap (calyx) attached, using a twisting motion to avoid damaging the plant. Harvest in the morning for the best flavor, as the sugars will be most concentrated after a cool night.

To encourage continued production, pick berries regularly as they ripen. Remove any overripe or damaged fruit to prevent disease. As the first frost approaches in early October, harvest any remaining ripe berries. Don't expect green berries to ripen off the vine; they won't.

Here are some common problems you might encounter with strawberries in our Mountain West gardens:

Gray Mold

• What it looks like: Fuzzy gray mold on berries, especially after wet weather.
• What causes it: A fungal disease that thrives in humid conditions and on damaged fruit. Our cool nights and occasional summer showers can create favorable conditions.
• How to fix/prevent it: Improve air circulation by spacing plants properly and removing dead leaves. Avoid overhead watering. Pick berries regularly and remove any infected fruit immediately.

Slugs

• What it looks like: Irregular holes in leaves, especially low-growing plants. Silvery slime trails on leaves and soil. Damage worse at night.
• What causes it: Gastropods that feed at night in moist conditions. They hide under mulch, boards, and debris during the day.
• How to fix/prevent it: Beer traps (shallow dish of beer sunk into soil). Iron phosphate bait (pet-safe). Remove hiding spots. Water in morning so soil surface dries by evening. Copper tape around beds. Diatomaceous earth around plants.

Birds

• What it looks like: Missing or pecked-at berries.
• What causes it: Birds love ripe strawberries!
• How to fix/prevent it: Cover your strawberry plants with netting or row covers. Use bird-scaring devices like reflective tape or decoy predators.

Strawberry Crown Borer

• What it looks like: Wilting plants, stunted growth, and small, white grubs inside the crown of the plant.
• What causes it: A beetle larva that tunnels into the crown of the strawberry plant, weakening or killing it.
• How to fix/prevent it: Remove and destroy infested plants. Rotate your strawberry bed to a new location every few years. Use beneficial nematodes to control the larvae in the soil.

Verticillium Wilt

• What it looks like: Lower leaves yellow, wilt, and die, progressing upward. One side of plant may be affected first. Brown streaks in stem cross-section.
• What causes it: Soil-borne fungus that persists for years. Cooler soil temperatures favor it (unlike fusarium). Wide host range.
• How to fix/prevent it: No cure — remove infected plants. Rotate with non-susceptible crops (corn, grains). Solarize soil. Plant resistant varieties (look for 'V' on labels).

Mountain West Specific Challenges: Our intense sun can sometimes scorch the berries, so consider providing some afternoon shade during the hottest part of the day. Low humidity helps prevent some fungal diseases, but it also means you'll need to be extra diligent with watering. Hail can also be a major problem, so protect your plants with netting if hail is in the forecast.

Companion planting can help your strawberries thrive in the Mountain West.

Good companions include lettuce and spinach, which provide ground cover and help retain moisture in our dry climate. Onions and garlic deter pests like aphids and spider mites. Thyme is a great ground cover that also attracts beneficial insects. Borage attracts pollinators and deters strawberry pests.

Avoid planting strawberries near broccoli, cauliflower, peppers, and tomatoes. These plants can compete for nutrients and are susceptible to verticillium wilt, a disease that can also affect strawberries. Keeping these plants separate minimizes the risk of spreading disease and ensures your strawberries get the resources they need to flourish.