Learn About Strawberries

Posted in: Strawberries
Learn About Strawberries

How To Sow    How To Grow    Tips    Common Pests    FAQ

How to Sow

  • Choose a location with loose, well-drained soil containing plenty of organic matter.
  • Strawberries may also be planted in containers or pyramid gardens, as an edging for flower and shrub borders or in matted beds and rows.
  • To grow in rows, space strawberry plants 18-24 inches apart in rows 3-5 feet apart. Runners will form new plants and eventually form a solid bed.

Planting Bare Root Plants:

  • Soak roots in lukewarm water two hours before planting.
  • Trim roots to 3 inches long and pick off any blossoms or dead leaves.
  • Using a trowel, open a hole large enough to spread roots out without bunching roots.
  • Set plants in the hole so that the crown is level with the surrounding soil line.
  • Press soil firmly against roots.
  • Water frequently until plants are growing vigorously.

Planting Potted Plants:

  • Make sure the root ball is sufficiently moist.
  • Carefully unpot the plant.
  • Set plants so the crown is level with the surround soil line.
  • Back fill the hole with soil and press soil firmly against the root ball.
  • Water frequently until plants are growing vigorously.

How to Grow

  • Apply a light mulch to keep weeds down, conserve moisture and keep fruit clean.
  • After harvest, remove old foliage. Be careful not to injure the crowns.
  • Fertilize beds in early summer and again in September with a balanced fertilizer. Do not fertilize if plants are flowering.
  • Watering is very important in early summer and September. 
  • Note that June-bearing plants produce the second year after planting. Cut all runners off during the first year, leave 2-3 runners the second year.
  • Winter protection for all strawberry varieties is important in most northern areas. Apply a mulch of straw or other loose organic matter 2-3 inches deep over the plants after the ground freezes but before the temperature drops below 20 degrees F. In spring, pull the mulch back into the rows.

Growing Tips

  • Pick the fruit as it ripens, when fully red.
  • Pick with a short piece of stalk attached.
  • Regular picking will help keep the plants fruiting.
  • Fruits are best eaten straight off the plants, and may be kept for up to a week in the refrigerator if kept dry. They are also easily frozen, or made into preserves.

Common Disease Problems

Black Root Rot: This is caused by a pathogen that attacks damaged roots, and is also worse when plants are stressed by drought, winter injury or poor nutrition. When carefully dug up, the finer feeder roots have rotted away and the thicker roots will have random gray to reddish brown sunken blotches which spread to cover large areas of the roots. Infected roots are soft and mushy. The plant slowly declines as it is challenged to take up water and nutrients from the soil. Burpee Recommends: Prepare beds to provide good drainage and soil solarization can help keep black root rot a minor problem. Cultivate carefully around the plants when weeding to avoid root damage. Provide adequate winter protection in colder areas.

Botrytis: Gray mold can appear on the fruit at any stage. Lesions develop near the stem end or on the side of the fruit touching other decayed fruit, soil, or standing water. Berries may become cottony white while flowers turn brown. Crown rot attacks plants where the leaves and flowers attach to the crown of the plant at the soil line. Burpee Recommends: Plant in raised beds, use plastic mulch to prevent the berries from touching the soil. Do not water overhead. Space plants appropriately to create good air circulation. Remove weeds that overcrowd plants and may spread the disease. Remove moldy fruit. Be sure not to bury the crown of the plant when planting.

Powdery Mildew: This fungus disease occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends: Avoid powdery mildew by providing good air circulation for the plants by good spacing and pruning. Contact your Cooperative Extension Service for fungicide recommendations.

Red Stele: This soil borne fungus attacks roots making them rot and unable to take up water and nutrients from the soil. When the root is cut lengthwise the core is red. Severely diseased plants have young leaves that are blue-green and older ones that are red, yellow or orange. Burpee Recommends: Remove infected plants and destroy them. Make sure your plants have adequate drainage. Plant resistant varieties. Do not plant strawberries where the disease has occurred.

Verticillium wilt: First seen on leaves in late spring after fruit production has begun. Leaves turn brown along margins and between veins. Leaves will wilt and dry up as the disease progresses. Burpee Recommends: Rotate crops and do not plant strawberries in a bed that held crucifers, cucurbits, eggplant, tomato, potato, or mint in prior years.   

Common Pest and Cultural Problems

Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.

Lygus Bugs (Tarnished Plant Bug): Lygus bugs are ¼ inch long and are green or brown with yellow markings. Nymphs are flightless and smaller than the adults. They suck on stem tips and flower buds and inject a toxic that deforms roots, stems and ruins flowers. Burpee Recommends: Because lygus bugs over winter in garden debris, remove all debris after the first frost. Contact your Cooperative Extension Service for insecticide recommendations.

Slugs: These pests leave large holes in the foliage or eat leaves entirely. They leave a slime trail, feed at night and are mostly a problem in damp weather. Burpee Recommends: Hand pick, at night if possible. You can try attracting the slugs to traps either using cornmeal or beer. For a beer trap, dig a hole in the ground and place a large cup or bowl into the hole; use something that has steep sides so that the slugs can’t crawl back out when they’re finished. Fill the bowl about ¾ of the way full with beer, and let it sit overnight. In the morning, the bowl should be full of drowned slugs that can be dumped out for the birds to eat. For a cornmeal trap, put a tablespoon or two of cornmeal in a jar and put it on its side near the plants. Slugs are attracted to the scent but they cannot digest it and it will kill them. You can also try placing a barrier around your plants of diatomaceous earth or even coffee grounds. They cannot crawl over these.

Spittlebugs: These hopping insects protect themselves from predators with a white foam while the young insects feed on the leaves and stems. When the insects emerge they are hoppers with large "froggy" eyes. There is only one generation each year but the larvae can hatch over a period of several weeks as the eggs were laid in the fall. Burpee Recommends: To control wash the foam off with a strong water spray. This will usually also kill the larvae. Do this once or twice a week for as long as needed. The damage is usually minimal.

Strawberry Crown Borer: Larvae are white with brown heads and feed on the crown and root tissue of plants. Adults are black with two to three bright yellow bands. If infested, plants will wilt and become stunted. Strawberry foliage will turn red. Plants will separate from the roots when pulled. Burpee Recommends: Removal of damaged plants or prune out infestations. Clean debris under and around plants.

FAQ

Will I get fruit this year? While you can, it is best to remove all flowers until June. June-bearing strawberries should not be allowed to produce a crop the first year; Day-Neutral strawberries may be allowed to develop a fall crop.

Do I need more than one variety?  No, they are self-fruitful.

Why is my ‘Purple Wonder’ strawberry red and not purple? It is not ripe yet, it will start out red but mature to purple.

Can I grow strawberries in a greenhouse? Our strawberry varieties require a cold period in order to produce fruit so they are not recommended for greenhouses or tropical climates.

Can I grow strawberries in containers? Yes strawberries are great for containers, especially pyramid gardens or strawberry jars.

October 29, 2021
©2023 W.Atlee Burpee & Co