By Charles Marr
Kansas State University
For the last several weeks, I have been writing about some things you might consider giving as horticultural gifts for the holiday season.
However, I am going to take a little diversion this week to write about something that is very timely to do now--winter mulching.
The time between Thanksgiving and Christmas is a good time to do some winter mulching. There are two main reasons to mulch.
One is to modify fluctuations in temperature by proving a cover to stabilize shifts in temperatures that may occur during the winter months.
Freezing temperatures at night and warm temperatures during the day often cause freezing and melting cycles that can pull some plants out of the ground. This action often is called "frost heaving" and is eliminated when we use a mulch. The mulch insulation prevents the rapid warming during the day--stabilizing the conditions to a more uniform temperature. Crops, such as strawberries and other ground-cover plants, are benefited by this winter mulching.
In this case, we want to use a mulch that is fairly coarse--won't pack down tight--and is fairly stable--won't blow away or deteriorate. Probably, wheat straw and old hay are the two materials of choice for this type of winter mulching materials. You also may consider adding a wire mesh cover (such as woven wire fence) over the straw to keep the mulch in place.
The second reason for winter mulching is to protect plant growing areas from severe winter temperature injury. This is done to prevent the temperatures from dropping so low. In this case, more dense materials may serve to do a better job mulching. Roses, especially hybrid tea roses, are one crop we often think about mulching in the winter for this reason. When mulching roses, a mound of soil around the base of the plant or a mound of compost or finely pulverized leaves makes a better mulch covering than straw. This covering provides some form of insulation to prevent the very cold temperatures at night that often become a problem for us, in some seasons.
We need to make sure our mulch materials are applied after all growth for the year is over. That is why we don't get excited about mulching too early. If you mulch while the plants still are growing, you might get a lot of soft, succulent tissue up under the mulch that is very subject to cold injury.
In a similar manner, you want to make sure the mulch material is removed in the spring before any serious growth begins to develop. Usually, mid to late March is a good time to think about removing mulch materials. So, write a late March date on your calendar to remind you what to do then.
If it still is freezing cold in late March, then delay a little longer. But if we are having some warm, sunny days and there is a little sign of greening up in plants in the landscape, then be sure to get that mulch removed.
There are some commercial mulching and covering devices you can purchase, such as insulating coverings and foam cone-shaped covers that commercial dealers have for you to purchase. They could be used, but they don't work much better than some of the natural materials you probably can find around the landscape.