a bowl full of homegrown strawberries

'Jewel' strawberries grown in a home garden. Photo: Christa Carignan, UME

Updated: April 10, 2024

About strawberries

Strawberry plants are low-growing perennials that can be cultivated successfully in rows, beds, or even pots and make an attractive groundcover when not fruiting. Today’s strawberry varieties got their start in the 18th century as hybrids between a North American species (Fragaria virginiana) and a South American species (Fragaria chiloensis).

The strawberry plant is composed of leaves, a crown (compressed, modified stem), and a root system. Fleshy buds emerge from the crown and produce leaves, flowers, and runners (stolons). As the runners grow from the original “mother” plant, they produce “daughter” plants where their nodes touch the soil.

Strawberry plants bloom as days lengthen in the spring. Buds that produce next year’s flowers are formed in late September as days shorten. Bees pollinate strawberry flowers.

The structure of strawberry fruits is unusual compared to other familiar species. Strawberry fruits have many small seeds (achenes) embedded in the fruit skin. The fruit flesh is actually the enlarged receptacle (fruit stem). The first fruits are the largest, and each succeeding set of berries will be smaller during the fruiting period. Insufficient bee visits, extreme weather (frost damage to early flowers), pests, and diseases are factors that can cause reduced yields and misshapen fruits.

Types and cultivars

  • June-bearing: produce fruit in May and June; the most commonly grown type
  • Day-neutral: longer flowering season, with most fruit ready for harvest in spring and late summer/early fall, with smaller amounts produced in between
 
Recommended Strawberry Cultivars 
Cultivar Type Comments
Annapolis June-bearing Medium to large, firm, glossy, light-red fruit. Good flavor.
Allstar June-bearing Very large, elongated, light-colored, and flavorful. Productive mid- to late-season harvest.
Earliglow June-bearing The standard for flavor and early-ripening varieties. Small to medium-sized deep-red fruit.
Jewel June-bearing Large, bright-red, firm berries. Prone to verticillium wilt and red steele.
Seascape Day-neutral Plants produce large, good-quality fruits throughout the season.
Tribute Day-neutral Vigorous, disease-resistant plants. Medium size, slightly acidic berries.
Tristar Day-neutral A University of Maryland release, the day-neutral standard. Sweet, disease-resistant.

Planting strawberries

Growing conditions: Choose a location receiving full sun in summer. Strawberry plants have a shallow, fibrous root system, making it somewhat more vulnerable to very dry or wet soil conditions. If your soil drains slowly, build a raised bed at least 12 inches above grade.

Plant in spring:

  • Young starter plants are typically available bare-root. Order bundles of bare-root plants in January for March delivery. 
  • Seeds can also be purchased. Seeds must first be refrigerated (stratified) for about one month to break dormancy. They can then be germinated and grown indoors for 6-8 weeks before transplanting into garden soil.
  • Plant outdoors in March or early April when the soil begins to warm.

Getting transplants established:

  • Trim long roots to within 4 to 6 inches of the crown, and set plants with half the crown below the soil level with roots fanned out. 
  • Fertilize plants lightly with a complete liquid or granular fertilizer (containing all three major nutrients, N-P-K).
illustration of a strawberry plant showing that the crown should be set at the soil line
Correct strawberry planting depth (second horizontal line from the top )

Plant care

Encouraging productivity: 

  • For June-bearers, remove the flowers for the entire first season to direct the plant’s resources into developing a large root system and healthy plant.
  • Fertilize June-bearing plants after the harvest season, and day-neutral plants once a month, May through September.

Mulching and weeding: 

  • Use an organic mulch for weed suppression and to keep fruit lying on the ground cleaner. Straw is a traditional mulch for strawberries, but other biodegradable materials can be used.

  • Remove weeds promptly. Weeds encourage high populations of plant bugs and other insects that can damage the fruit, promote disease development by reducing air circulation (leaves stay wet longer), and compete strongly with shallow-rooted strawberry plants for nutrients and water.

Harvesting 

  • Fruits start ripening around 5 weeks after bloom. The harvest period is usually 3 weeks long, but can vary due to spring weather conditions.
  • Strawberries should be left on the plant 1 to 2 days after turning fully red. Berries picked when not fully red will continue to change color but will not sweeten.
  • If possible, pick early in the day when berries are cool. Twist the stem and fruit from the vine.
  • Wash before eating, not before storage. Berries can be refrigerated for 3 to 5 days.

Weather protection

  • Shallow roots make plants prone to being pushed out of the soil (heaving) with winter freezes and thaws. Protect plants by mulching them with straw or mower-shredded tree leaves in late fall when night temperatures approach 20℉.
  • Row covers are useful in preventing winter damage, promoting early bloom, protecting flowers from spring frosts, and excluding flying insect pests. Flowers that are self-pollinated, and pollinated by wind and insects are fully pollinated and produce the largest, well-shaped fruits. Be sure to remove the row cover just before flowering begins to give bees access.
straw is used to protech strawberry plants
Strawberry bed mulched with straw. Photo: Jon Traunfeld, UME

Training and renovation

  • June-bearing cultivars are typically maintained using either of two systems:
    • Hill system: Space plants one foot apart in all directions and remove all runners to encourage more flower stalks.
    • Matted row system: Space “mother” plants 18 to 24 inches apart, in rows at least 36 inches apart. Allow runners to root freely in all directions and fill in with “daughter” plants. Keep the beds narrow (12 inches), if possible, to maximize sunlight penetration. (It helps to drive a short stake in the ground at the head of each row so you can identify the mother plants later.)
june-bearing strawberries are planted with mothers in the middle and daughter plants on the side
Strawberry matted row system
  • Plant day-neutral cultivars about 5-9 inches apart in all directions. Remove flowers for the first 4-6 weeks after planting, and then allow plants to fruit. Remove runners throughout the growing season. They can be treated as annuals and replanted each year, or mulched and overwintered to produce a harvest for a second year before replacement.

Due to diseases and crowding, june-bearing cultivars typically decline after 3-4 years. You can start a new bed with fresh plants in a new location (don’t move runners from an old bed with insect pests and diseases) or renovate the old bed.

Renovation 

After the end of the second-year harvest:

  1. Mow or hand-prune plants to a height of 2 to 3 inches or just above the crowns.
  2. Apply fertilizer.
  3. Thin daughter plants to 6 inches apart. Use a garden spade or other hand tool to turn under or remove runners that strayed beyond the 12- to 18-inch-wide growing bed, leaving a bed of mingled mother and daughter plants.

Repeat the third year: mow, fertilize, and thin daughter plants to 6 inches apart.

In the fourth year, alter this process: turn under the mother plants and allow only the strongest daughter plants to form the 12- to 18-inch-wide beds. Plant new plants every three years if growing in containers.

Resource

(Video) Renovating a Strawberry Bed | University of Maine 

Plant and pest problems

Common strawberry diseases include strawberry leaf spot (Mycosphaerella fragariae), anthracnose fruit rot, and gray mold (Botrytis rot). Insect pests include tarnished plant bugs, sap beetles, leafhoppers, and spotted-wing drosophila. Slugs, birds, squirrels, and other wildlife will feed on fruits.

a strawberry with mold on it
Gray mold. Photo: Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org

Strawberry foliage, crowns, and flowers are very vulnerable to damage during periods of temperature fluctuations in late winter to early spring. The plant care section above provides information on overwintering strawberry beds.

brown strawberry leaves due to cold weather damage
Strawberry foliage exhibiting cold and wind injury. Photo: Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org

Additional resources

Pest Management Guide (click Home Fruit) | Virginia Cooperative Extension
UME recommends this guide for Maryland’s home fruit gardeners.

Strawberry Diagnostic Key | NC State University Extension

Author: Jon Traunfeld, Extension Specialist. Reviewed by Miri Talabac, Lead Horticulture Consultant, and Christa Carignan, Digital Horticulture Education Coordinator. 3/2024

Still have a question? Contact us at Ask Extension.