Gordon Johnson, Extension Vegetable & Fruit Specialist; email@example.com
In 2011, the common observation was that later planted Chandler strawberries out-yielded earlier plantings. This illustrates the dramatic effects that fall and winter temperatures can have on plasticulture production.
Chandler has been our main plasticulture berry and has shown consistently high yields. For most of Delaware, the recommendation has been to plant Chandler the second week in September. In conversations with Dr. Barclay Poling, who is the recognized expert in plasticulture production in North Carolina, he stated that 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, as it is less temperature sensitive than Chandler in the fall and is not prone to putting on excessive growth. Camarosa is however sensitive to high April temperatures which can halt flowering in the spring, but in normal years will extend the season better than Chandler.
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, such as Festival and Bish, we still do not have enough research in our region to know if they can be replacements for 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 of time 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. Because plants are smaller and there are fewer berries per plant, it should be planted at a higher density than Chandler.