Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu
Chandler has been our main plasticulture strawberry and has shown consistently high yields. For most of Delaware, the recommendation has been to plant Chandler the second week in September. However, Chandler is more sensitive to fall and winter temperatures than other varieties and in warmer conditions Chandler will put on too much growth, leading to small berries the following spring; therefore, knowing when to plant is difficult. If you could accurately predict fall and winter temperatures, you could adjust planting dates, but, of course, this is not possible.
One strategy has been to make multiple plantings of Chandler one week apart starting the second week in September. This will insure that a part of the crop will come out of winter with the proper number of crowns (not too many, not too little). Unfortunately, this means that part of the crop will be low yield and part will have small berries.
Another strategy is to switch to varieties that are less susceptible to putting on too much growth. This is where the variety Camarosa may have a fit; it is less temperature sensitive than Chandler in the fall and is not prone to putting on excessive growth. Camarosa has not performed as well on Delmarva compared to North Carolina.
Sweet Charlie, the early berry that also can put on a second late crop, is normally planted 7-10 days ahead of Chandler. It is not an option to replace Chandler. For other varieties being tried, we still do not have enough research in our region to know if they can be replacements for Chandler. Flavorfest has performed well but does not produce over as long of a season as Chandler.
Another strawberry that should be considered by growers is Albion, a day-neutral variety. It too is not sensitive to when it is planted in the fall. While much less productive in the main Chandler season, it has some unique properties that make it valuable to growers. First, it will give some early production, ahead of Chandler. Second, even though production is lower, it produces evenly over an extended period from April through early July. In general, it will give 5-6 weeks more production than Chandler. It is a large, firm berry, that, while not as sweet early in the season, has good quality in May and June. Research at Cornell and Penn State has shown that Albion needs much higher levels of nitrogen than the other common varieties and when fertilized properly will give higher yields over an extended period.