Strawberry in Zone 5A — Mountain West

Strawberries are worth the effort in our Mountain West gardens. Nothing beats the taste of a sun-ripened strawberry, especially when those cool nights help concentrate the sugars. Plus, they're incredibly versatile—jams, pies, fresh eating, you name it. Growing your own is deeply satisfying.

Our high altitude and short growing season (around 138 days) present challenges, but with careful timing and attention, you can absolutely enjoy a successful strawberry harvest. Focus on getting plants in the ground at the right time and providing consistent care.

Transplant your strawberry starts outdoors from late April through mid May, after the risk of hard frost has passed. Whether you bought bare-root plants or potted starts, be sure to harden them off first. Give them about a week of gradual outdoor exposure, increasing the time each day, before planting them in their final location.

Space your strawberry plants 12-18 inches apart to allow for good air circulation and spreading. At transplant time, keep an eye on the weather. We can still get late-season snow or hail in the Mountains, so be ready to cover your young plants if needed.

Strawberries need consistent moisture, especially when they're fruiting. While our Mountain climate is dry, aim to keep the soil evenly moist, but not waterlogged. Drip irrigation is ideal because it delivers water directly to the roots and avoids wetting the foliage, which can lead to fungal problems in our cool nights even in summer.

During the active growing season, from late spring through harvest, water deeply about 1-1.5 inches per week. Use the "finger test" to check soil moisture—stick your finger about 2 inches into the soil. If it feels dry, it's time to water. Water at the base of the plants, avoiding overhead watering whenever possible.

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

Strawberry pruning is pretty minimal, but it does impact your yield. During the growing season, remove the runners (those little offshoots that spread out) if you want to direct the plant's energy into fruit production. If you want more plants, let the runners root and establish new plants.

For June-bearing varieties, renovate the beds after harvest by mowing or cutting back the foliage. This encourages new growth and better yields the following year. As the first frost approaches in late September, remove any dead or diseased leaves to help prevent overwintering of pests and diseases. Leave the healthy foliage to protect the crown of the plant.

You can expect your first strawberry harvest from late July through early September, depending on the variety and the weather. The berries are ready to pick when they're fully red, fragrant, and have no white shoulders. They should pull easily from the plant with the green cap (calyx) still attached.

Harvest in the morning for the best flavor, as the berries will be cooler. Pick regularly to encourage continued production. Strawberries don't ripen off the vine, so only pick the fully ripe ones.

As the first frost approaches in late September, harvest any remaining ripe or nearly ripe berries. You can use the nearly ripe ones for jams or preserves. Remove any decaying fruit to prevent disease.

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 the berries, especially during wet weather.
• What causes it: A fungal disease that thrives in humid conditions. While we have low humidity, cool nights can create enough moisture for it to take hold.
• How to fix/prevent it: Improve air circulation by spacing plants properly and pruning excess foliage. Remove infected berries immediately. Apply a fungicide if necessary.

Slugs

• What it looks like: Irregular holes in leaves, especially low-growing plants. Silvery slime trails on leaves and soil. Damage worse at night and in wet weather.
• What causes it: Gastropods that feed at night in moist conditions. 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 berries, pecked fruit.
• What causes it: Birds love strawberries!
• How to fix/prevent it: Netting is the most effective solution. Cover your strawberry plants with bird netting as the berries begin to ripen.

Strawberry Crown Borer

• What it looks like: Wilting plants, stunted growth, small holes in the crown of the plant.
• What causes it: A beetle larva that tunnels into the crown of the plant.
• How to fix/prevent it: Remove and destroy infested plants. Rotate crops. Use beneficial nematodes.

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 providing some afternoon shade during the hottest part of the day can be helpful. Hail can also damage the plants and berries, so consider using row covers if hail is in the forecast.

Companion planting can benefit your strawberries. Lettuce and spinach make good companions because they provide ground cover and help retain moisture. Onions and garlic deter pests with their strong scent. Thyme is another great choice, as it attracts beneficial insects and repels pests. Borage is said to improve strawberry flavor and attract pollinators.

Avoid planting strawberries near broccoli, cauliflower, pepper, or tomato. These plants can compete for nutrients and may attract pests or diseases that can also affect strawberries.