Strawberry in Zone 5B — Mountain West

Strawberries are absolutely worth the effort in our high-altitude gardens. The taste of a sun-ripened strawberry, bursting with flavor intensified by our cool nights, is unmatched by anything you'll find in the store. Plus, they're incredibly versatile – from jams and pies to fresh eating straight from the garden.

Our short growing season and intense sun can be a challenge, but with careful timing and a little extra attention, you can absolutely enjoy a bountiful strawberry harvest. We typically have around 149 days between frosts here, which is just enough time to get those berries ripening.

Transplant your strawberry starts outdoors from late April through mid May, after the danger of hard frost has passed. It's best to buy bare-root plants or potted starts in spring, as growing from seed can be slow and a bit unreliable for our short season.

Before planting, be sure to harden off your transplants by gradually exposing them to the outdoors for about a week. This helps them adjust to the intense sun and cooler temperatures we often experience this time of year. Space plants 12-18 inches apart to give them room to spread.

Keep an eye on the weather forecast – a late-season cold snap can still happen. Be prepared to cover your newly planted strawberries if frost threatens.

Strawberries need consistent moisture, especially when they're fruiting. They're not drought-tolerant, so you'll need to stay on top of watering. Drip irrigation is ideal, as it keeps the foliage dry, which helps prevent fungal problems in our dry climate.

During the spring, when the plants are establishing, water deeply once or twice a week, aiming for about an inch of water each time. As the weather warms up and the berries start to develop, increase watering to two to three times a week, providing 1-2 inches of water. The "finger test" is your friend: stick your finger about 2 inches into the soil near the base of the plant. If it feels dry, it's time to water. Always water at the base of the plant, avoiding overhead watering as much as possible.

Signs of underwatering include wilting leaves and dry, shriveled berries. Overwatering can lead to root rot, indicated by yellowing leaves and a general decline in plant health. Mulch heavily around your strawberry plants with straw or wood chips to help retain moisture and suppress weeds.

Strawberry pruning is pretty minimal. Focus on removing runners, those little offshoots the plant sends out. These runners can steal energy from fruit production, so snip them off unless you want the plant to spread and create new plants.

For June-bearing varieties, renovate the beds after the harvest is complete. This means mowing or cutting back the foliage to about an inch above the crown to encourage new growth. As the first frost approaches around early October, remove any dead or diseased foliage to prevent overwintering pests and diseases. Leave the healthy foliage in place to insulate the crowns.

You can typically expect your first strawberry harvest from mid July through late August. The berries are ready to pick when they are fully red, fragrant, and have no white shoulders. The flavor won't improve after picking, so wait until they're fully ripe.

Gently pick the berries with the green cap (calyx) attached. Harvesting in the morning, after the dew has dried, will give you the best flavor. To encourage continued production, harvest ripe berries regularly, every few days.

As the first frost approaches in early October, harvest any remaining ripe or nearly ripe berries. Even green berries can be used for jams and preserves. After the first hard frost, you can mulch the plants heavily with straw for winter protection.

Here are some common strawberry problems we face in the Mountain West:

Gray Mold

• What it looks like: Fuzzy gray mold on berries, especially during cool, wet periods. Can also affect blossoms and foliage.
• What causes it: A fungal disease favored by cool, humid conditions. Spores are spread by wind and splashing water.
• How to fix/prevent it: Improve air circulation by spacing plants properly and pruning out dense foliage. Remove infected berries and foliage promptly. Avoid overhead watering. Our low humidity often helps, but watch out for this during unusually wet spells.

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. 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, and general evidence of birds feasting on your crop.
• What causes it: Birds love strawberries!
• How to fix/prevent it: Netting is the most effective solution. Cover your strawberry plants with bird netting before the berries start to ripen. You can also try using visual deterrents like shiny ribbons or scarecrows, but these are often less effective.

Strawberry Crown Borer

• What it looks like: Wilting plants, stunted growth, and small, white grubs boring into the crown of the plant.
• What causes it: A beetle whose larvae feed on the crown of the plant, disrupting water and nutrient flow.
• How to fix/prevent it: Remove and destroy infested plants. Rotate crops. Use beneficial nematodes to control larvae in the soil. Keep the area around your strawberry patch free of weeds and debris.

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. 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. Our alkaline soil can also be a problem, so amend the soil with plenty of compost and organic matter before planting. Hail can also decimate a strawberry patch in minutes, so consider using row covers or other protective measures if hail is in the forecast.

Good companion plants for strawberries include lettuce and spinach, which provide ground cover and help retain moisture. Onions and garlic can deter pests, while thyme and borage attract beneficial insects that pollinate the flowers.

Avoid planting strawberries near broccoli, cauliflower, peppers, and tomatoes. These plants can compete for nutrients and may harbor diseases that can affect strawberries. Tomatoes and peppers can also stunt the growth of your strawberry plants.