New strawberry plantings should be set early in the growing season so that mother plants become established while the weather is still cool. The mother plants develop a strong root system during this cool period when soil temperatures are between 65 and 80 degrees F. The most appropriate planting time is mid- to late March in southern Kansas and late March to mid-April in the northern areas of the state.
Later in the season, runners and daughter plants develop. The earlier the mother plants are set, the sooner the first daughter plant will be formed and take root. These first daughter plants will be the largest plants at the end of the growing season and will bear more berries per plant the following spring.
When planting is done later, the higher temperatures stress the mother plants resulting in reduced growth, weaker mother plants and delays in daughter plant formation. Fewer and smaller daughter plants produce fewer berries, resulting in a smaller crop.
Remove all flowers during the first year. New plants have limited energy reserves that need to go toward establishing the mother plants and making runners rather than making fruit. If fruit is allowed to develop the first year, the amount of fruit produced the second year is drastically reduced due to smaller, weaker daughter plants.
Research in Illinois has shown that the straw mulch should be removed from strawberry plants when the soil temperature is about 40 degrees F. Fruit production drops if the mulch remains as the soil temperature increases. There are likely to be freezing temperatures that will injure or kill blossoms, so keep the mulch between rows to conveniently recover the berries when freezing temperatures are predicted.
Strawberries (June-Bearing): June-bearing strawberries are not fertilized in early spring as this can make the berries soft and more prone to rot. Fertilize at renovation and again in late August to early September. In most cases, strawberries need primarily nitrogen, so the recommendations are for a high nitrogen fertilizer such as a 27-3-3, 29-5-4, 30-3-3 or something similar. Though recommended for lawns, these fertilizers will also work well for strawberries as long as they do not contain weed killers or crabgrass preventers. Apply ½ cup for every 10 feet of row.
Strawberries (Everbearing or Day-Neutral): Fertilize in the spring as growth starts and again in early August. Use the rates recommended for June-bearing strawberries. Everbearing (dayneutral) strawberries are not renovated.
Controlling Weeds in Strawberries
Strawberries are one of the most popular fruits, but gardeners often have problems with weed control. Strawberries form a mat of plants, which makes hoeing difficult. Gardeners must pull weeds by hand or use herbicides. Although there are no weed preventers available for homeowners to use on strawberries, Poast (sethoxydim), a grass-killing herbicide, can be used after weedy grasses have emerged. It can be sprayed directly over strawberries without harm but should not be applied within 7 days of harvest. You can find Poast in Hi-Yield Grass Killer and Monterey Grass Getter.