What a disappointment that the first strawberries of the season were so deformed. There are various names for the misshapen berries including button berries, nubbins and catfaced or cockscomb berries.
The plants look healthy and are growing well. The winter rains cleansed the soils of harmful salts.
There are lots of new strawberries on the ‘Seascape’ and ‘Sequoia’ plants. These are not deformed. I Googled misshapen strawberries and did find some possible causes such as poor pollination, boron deficiency, cold injury and various pest infestations.
The best information came from a search at my go-to website, The University of California Integrated Pest Management Program. It’s a great resource for California gardeners. Here’s what I learned.
Low temperature injury to strawberries
Low temperatures can kill flowers or cause the development of misshapen fruit, depending on the severity of chilling and the stage of flower development when it occurs. Cold, dry weather in the fall may interfere with flower bud development, causing fruit to form multiple tips the following spring.
Temperatures below about 60°F during flowering may prevent pollination of some simple, one-seeded fruits, resulting in distorted, "catfaced" berries. The damage appears identical to the catfacing caused by lygus bugs, but lygus bug damage occurs in late spring and early summer and low-temperature injury symptoms develop in early to mid-spring.
Sprinkler irrigation used when temperatures are expected to be below freezing can help minimize frost injury.
So my take-away is that our cool winter weather and poor pollination may be responsible for the oddly shaped berries. It’s unlikely there are pests afoot and my soil has been enriched with loads of compost and organic fertilizer. From my brief online research it appears that may be other causes of misshapen strawberries in other parts of the country and in the late spring and summer seasons.
The strawberry flavor still came through and the frozen blueberries obscured the funny shapes.