Strawberry fields forever? Well the Beatles didn’t get that one quite right.
Although strawberries are not annuals, they produce good quality berries for only a few seasons. Within a couple of years of planting, berry size and number start to decline and plants seem to lose their vigor. The decline of strawberry plants is due to aging, overcrowding and viral and other diseases.
There is no way to prevent this decline, but you can keep June-bearing strawberries producing longer by renovating the rows each year after the harvest.
Before we go any further, it is important to realize that there are several types of strawberries: June-bearers, everbearers, and day-neutrals. June-bearers are the traditional strawberry that produces a single bumper crop of flavorful berries each year in June and July. Everbearers produce berries in June and again in late summer or early fall. Day-neutrals produce berries throughout the normal growing season. The renovation process applies to June-bearing strawberries only, not everbearing or day-neutral strawberries.
Start the renovation process after you have harvested your last June-bearing strawberry. The first step is to cut off all of the leaves on the plants because the leaves can be the source of diseases. Use a mower set on high or grass shears. Remove leaves to about one inch above the crown, being careful not to damage the crown where new leaves and fruit will arise.
Skip this step if you can’t do it within a week or two of harvest and by August 1 (but do the other steps). Shortly after the harvest, the plant will have a growth spurt and you could damage the new leaves that emerge. Plants also need sufficient time to regrow before fall.
Next, rake and remove all plant debris to discourage insect and disease problems. Remove any rotten or bug-eaten fruit and dispose of it in the compost pile.
Now thin out old, weak or diseased plants and rototill (or hoe) between the rows so that they are only 8 to 12 inches wide. Keeping the rows narrow prevents plants from shading each other, and will increase their productivity. In addition, the narrow rows are easier to harvest and allow better air circulation and light penetration which minimize fruit rot next season.
June-bearing strawberries produce lots of runners (baby shoots that can grow into full-sized plants). By the end of the summer, the row will be filled in with new plants and two feet-wide again.
Next, apply fertilizer to the rows. To encourage good plant growth and development, apply approximately five pounds of a 10-10-10 fertilizer to a 100-foot row. (A 10-10-10 fertilizer is 10 percent nitrogen, 10 percent phosphorus, and 10 percent potassium by weight.)
Finally, make sure your strawberries get at least one inch of water per week for the rest of the growing season. June-bearing strawberries initiate fruit bud development in late summer and early fall as the days shorten and temperatures cool; taking good care of your strawberries after renovation will pay off during next season’s harvest.
June-bearing strawberries that are well-maintained will remain productive for four or five years. Poorly managed beds may be productive for only one or two years. Protect your investment and renovate your June-bearing strawberries this year.
Jeanette Stehr-Green is a berry enthusiast and a WSU-certified Clallam County Master Gardener.