Strawberries are one of the easiest and most popular small fruit grown in the home garden. Attractive and flavorful, the strawberry is also nutritious. A cup of strawberries will supply more than the recommended human daily requirement of vitamin C with only 55 calories. A bed of 25-50 strawberry plants will produce enough berries for an average-sized family.
BOTANY
The strawberry (Fragaria ananassa) is an aggregate fruit with seeds or achenes embedded on the surface of a swollen receptacle. The number of cells in a strawberry is determined at the time of flower-bud initiation (previous fall for Junebearers). Size of the berry, however, is mostly influenced by irrigation, which affects the enlargement of the cells.
The perennial, herbaceous, low-growing strawberry plant is composed of leaves, a crown (a compressed, modified stem), and roots. Roots tend to be either semi-permanent (lasting more than one season) or temporary (lasting only days or weeks). Most occur in the upper 3-6 inches of soil, but can reach depths of 12 inches or more in lighter soils. As roots and leaves tend to develop at a higher level on the crown each year, root contact with the soil tends to decrease with time. The elevated plant tends to push itself out of the ground.
Inflorescences (flowers) develop from terminal buds on the plant. Plants with branched crowns (induced by short-days) may form multiple inflorescences. Lower temperatures (below 60 0 F) will also induce flower bud formation. Flower bud formation is generally inhibited when day/night temperatures exceed 72 0 /70 0 F.
Strawberries generally propagate vegetatively by producing runners (stolons). Runners arise from buds at the base (axils) of the leaves, in response to longer-days (more than 12 hours of sunlight) in June-bearing strawberries, Longer days occur from June through August. Dayneutral varieties generally produce fewer runners so they should be planted closer together in the bed.
STRAWBERRY TYPES AND CULTIVARS
There are basically three types of strawberries: June-bearers, everbearers, and day-neutrals. They differ primarily in their response to day length, which affects both berry and runner production.
June-bearers
June-bearers develop flowers in the early spring from buds initiated the previous fall under short-day conditions (less than 10 hours of light per day). It is essential during the fall (Septernber-November) that the plants have a full, well developed leaf canopy to produce sufficient energy for flowers to bud. June-bearers tend to outproduce other types of strawberries, but the crops are often lost due to late frosts in the spring. June-bearers are better adapted to warmer growing areas of the state.
Cultivars
'Guardian'- large, conic, glossy, light red fruit;good yields;, excellent flavor; good for desserts, preserves, and canning; resistant to Verticillium wilt and five races of red stele. ‘Robinson'- large, conic, blunt-ended berries; good producer; fair flavor; fair to good quality for desserts, canning and freezing; resistant to Verticillium wilt, but susceptible to red stele; good in warm weather. ‘Sequoia' - large, dark red berries; good producer over relatively long time; fair dessert and freezing quality; susceptible to red stele; good in warm weather. 'Surecrop' - medium to large wedge-shaped berries; secondary berries tend to be more conic; excellent, slightly tart flavor; excellent for desserts and freezing; resistant to Verticilliurn wilt, red stele, and drought. ‘Tioga' - medium to large, wedge-shaped berries; very good flavor; good dessert and freezing quality; no resistance to red stele; good in warm weather.‘Tufts' - large, long, wedged-shaped fruit; high yields; fair dessert but good freezing quality; susceptible to red stele.
EVERBEARERS
Everbearers initiate flower buds under long day conditions (more than 12 hours of sunlight). They will generally produce two main crops (spring and fall), but yield less than a single spring crop from a June-bearer. Everbearers, however, that lose a spring crop to frost will still produce a fall crop. Everbearers produce fewer runners and tend to form multiple crowns. Everbearers do not tolerate heat well, so they should be grown in the northern part of the state.
CULTIVARS
‘Fort Laramie' - large, bright red fruit; very aromatic; good dessert, freezing, and preserving qualities.‘Gem Everbearing' - ('Superfection') - dark red fruit; good dessert qualities. ‘Ogallala' -large, plump fruit; excellent for preserves; very hardy; good drought and disease resistance.‘Ozark Beauty' - large, firm, wedge-shaped, long-necked berries; excellent flavor; excellent for desserts, canning, freezing, and preserves; susceptible to Verticilliurn wilt and red stele. ‘Quinault' - large berry; good yields; good for desserts and preserves. ‘Streamliner' - large, bright red fruit; excellent flavor; good yields.
DAY- NEUTRALS
Day-neutral strawberries have the unique ability to flower and fruit under any day-length conditions. They will produce fruit from spring through fall with several peaks throughout the season. Temperatures above 70 0 F, however, will inhibit flower bud formation. Day-neutrals produce fruit and runners simultaneously, although runner production is generally less than that of June-bearers. Day-neutral runners often flower before initiating roots, which makes them excellent container plants, especially as hanging house plants in the winter.
SITE SELECTION
Earlier production can be achieved by selecting a southern exposure that warms earlier in the spring. Plants may have to be covered with a straw mulch or blanket at night to protect them if frost becomes a problem. Locations next to a house are often warmer due to heat generated from the home.
Strawberries prefer full sun, although afternoon shade may be needed in warmer areas of the state. However, shady locations can cause more vegetative plants with fewer berries and cause more disease problems.
Avoid planting strawberries after peppers, tomatoes, potatoes, eggplant, or okra, all of which are susceptible to Verticillium wilt. Sites planted to strawberries following sod may have to be treated to control white grub. Sites should also be free of noxious weeds.
