Once your matted-row strawberries are done fruiting for the season, it is time to renovate them so that they will produce well next year. A good strawberry planting in Kentucky can last 5-7 years before replanting. Renovation will help keep them producing this well by controlling weeds and thinning them out, so they don’t become too crowded.
If you have a significant amount of broadleaf weeds, apply 2,4-D (amine) no later than July 15 to selectively remove broadleaf weeds. It will take a couple of days for the 2,4-D to have an effect but within 3-5 days you need to mow off the leaves being careful not to cut into the strawberry crown.
This is a good time to take a soil test and check the pH and fertility levels. If your beds were properly fertilized at planting, they probably don’t need anything other than some nitrogen. Mowing off the leaves makes it easier to fertilize the plants because strawberry foliage is susceptible to fertilizer burn. It doesn’t matter if you use synthetic or organic fertilizer, but you want about 1.5-2.0 pounds of actual nitrogen per 1000 sq ft. Fertilize in early August after you get your test results back.
Until then though rows should be narrowed to 8 to 10 inches wide. Reduce row width with a rototiller. Growers often remove half of one side of the row to remove as many old plants as possible. If the strawberry plants are too thick in the remaining row they should be thinned to 5-6 plants per square foot. Crowded plants will produce fewer and lower-quality fruit. Once the rows have been narrowed and the plants thinned you can pull ½” of soil over the remaining plants from where you tilled. This will allow them to form new roots from higher on the crowns. Do not put too much soil over the plants as it can bury the crown and slow initiation of daughter plants inhibiting development.
Strawberries are cool-season plants so they will not grow vigorously in the summer. Keep them watered so they don’t die but do not expect much growth from them until you fertilize and then begin watering regularly in August.
Source: Shawn Wright, Horticulture Specialist University of Kentucky