Small strawberries? Poor pollination, lack of nutrients could be to blame
Question: We've had a strawberry patch for several years now, and at first it was great, but now it's not doing so well. The berries are very small, and the plants don't seem to produce as much as they used to. I don't remember the name of the variety, but they usually produce in late May or early June. Would fertilizer help? What else can we do to get our big berries back?
Answer: There are several reasons why your strawberry crop may not be up to snuff. I suspect in your case, a combination of the following reasons is to blame.
First, poor pollination can be the cause of small fruit size. Insects are required to move the pollen from flower to flower to initiate fruit set. If there aren't enough pollinators around, or if cold or wet weather keeps pollinators away, small fruit is often the result. We had a crazy spring in the weather department and I know my strawberries were in bloom before most pollinators were actively foraging. There isn't much you can do about this other than hope for a more “normal” spring weather pattern next season.
Lack of nutrients could also be a problem. When perennial fruits and vegetables, like strawberries, grow in the same location year after year, they can easily deplete the soil nutrients found within their root zone, leading to possible deficiencies. An inexpensive soil test will tell you if this is the case, but a yearly addition of an organic granular fertilizer (such as Garden-tone or Jobe's Organics) helps replenish the nutrients the plants use during growth. Apply the fertilizer according to package instructions in spring, when new growth begins. Just be sure to avoid any fertilizers that contain a lot of nitrogen as that will promote green growth, often at the expense of flowers and fruits.
Strawberry plants that are spaced too closely will also typically have smaller fruits. Be sure that each plant has ample room and receives good air circulation, which also cuts down on fungal diseases like fruit rot. Plants that are too close to each other compete for light, water and nutrients, leading to a stressful situation that could affect fruit set.
In addition to the above issues, the age of your plants may also be a factor. As strawberry plants age and produce several years worth of berries, they weaken. Pinching off the runners every year is one way to keep the plants strong, but even if you do this on a yearly basis, after four or five years, the plants will produce fewer and smaller berries. To remedy this, most fruit experts recommend a complete overhaul of your strawberry patch every five years. To do this, dig up and discard of all the old plants, amend the soil with a few inches of compost, and replant with new plants. This is best done in the spring.
Here's to excellent future strawberry harvests!
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden,” “Good Bug, Bad Bug,” and her newest title, “Container Gardening Complete.” Her website is jessicawalliser.com. Send your gardening or landscaping questions to firstname.lastname@example.org or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.