Strawberry mulch removal time
When to remove straw mulch from commercial strawberries is a frequently asked question.
I am frequently asked by strawberry growers when is the right time or exact date to remove straw mulch from matted row strawberry beds. Straw is frequently used to prevent winter injury in strawberry beds. With our late spring this year it is particularly hard to zero in on this important cultural practice.
The best method I can recommend for the proper timing for mulch removal is to look for the beginning of leaf growth. Strawberry growers will need to inspect their fields. Randomly pick several spots in a field and pull the straw off of two feet of row. If you see newly emerging leaves (they may be a yellow color) that are beginning to grow from the crown of the plant, generally that is telling you that the strawberries are ready to begin growth for the season and that straw needs to be removed. I would check this in about 10 to 15 spots in the field. Concentrating on the earlier fruiting strawberries is usually a technique that will help to pinpoint straw removal. If you are on heavy soil and your soil has not dried yet, wait for a cold morning when there is a crust on the soil surface to reduce soil compaction
The typical time for removing straw in Michigan is mid to late March for the lower half of the lower peninsula, mid to late March for the northern half of the lower peninsula, and in the upper peninsula most likely early April. Strawberries growing close to Lake Michigan may also be uncovered a bit later than inland sites. Before you remove straw, check the forecast, if cold weather is predicted, you can delay a few days.
The earlier you remove the straw mulch, the earlier fruit will mature. Early growth may also necessitate more frost protection. In a really late spring like we are having in 2011, there is also a danger of leaving straw on too long. A study was conducted a number of years ago in New England where straw was removed periodically over a six week period. The highest yields came from plants that were uncovered earliest in spring as was practical, following either snow melt or ability to move straw removal equipment through the field without creating ruts. The later the straw was removed the more yield was reduced.
I also suggest that a light layer of straw be left on the plants. This layer would be about an inch thick. Leaves and flowers can grow up through this thin layer. Many times this will help to reduce disease problems later in the season, and will also help prevent some weed seeds from germinating if bare soil is exposed to sunlight. Lastly, mulch removal just prior to a rain event helps the plants respond well and keeps the mulch in place.