When to Plant Plasticulture Strawberries, New Varieties to Trial

Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu

In some years, later planted ‘Chandler’ strawberries have 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. 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, as it is less temperature sensitive than ‘Chandler’ in the fall and is not prone to putting on excessive growth. ‘Camarosa’ can increase mid-to-late season spring sales when ‘Chandler’ quantity and quality declines as the temperatures increase.

‘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’.

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. It requires much more nitrogen than ‘Chandler’ to produce adequately sized plants and production.

New Varieties
Many other varieties have trialed in the region; however, we still do not have enough research in our region to know if they can be replacements for ‘Chandler’. One with great promise is ‘Flavorfest’. This variety was developed at USDA, Beltsville and is well adapted to our region. ‘Flavorfest’ has a prolonged growing season when compared to most other commercial varieties. It is similar to ‘Chandler’ when grown in plasticulture, but its yield is higher and berries larger. The plants are also vigorous and require less nitrogen than ‘Chandler’. ‘Rutgers Scarlet’ is another strawberry developed in the Mid-Atlantic. It has good flavor but moderate yields in regional trials. Two new North Carolina State varieties also have been released for 2019. ‘Rocco’ is an early season, medium-large, medium soft berry, with excellent flavor and is a very high yielder. It is best for pick your own and on farm sales. Consider it as a ‘Sweet Charlie’ alternative. ‘Liz’ is a mid-late season, medium-large, firm berry. It has good flavor and is a high yielder. It produces a large plant which covers berries and can make it hard to pick. It is best for pick your own and short distance shipping. Consider it as a ‘Camarosa’ alternative.

‘Flavorfest’ Strawberry

‘Rutgers Scarlet’ Strawberry

‘Rocco’ and ‘Liz’ Strawberries