Perennial care

By John Fulton

[November 10, 2008]  With a severe cold snap Sunday evening and Monday morning, we definitely had more than "frost on the pumpkin" -- we froze it. This is our signal to use a decent day to finish up those outdoor chores remaining. One of the last to be done is taking care of perennials.

Many perennials are better left standing over the winter than cutting them down. There are several reasons for this. In addition to many of the perennials having attractive foliage or seed heads, they offer food resources for birds. Many birds find the seeds of perennials particularly tasty. 

The stems of perennials also offer a place for some birds to hide during the winter. With some marginally hardy perennials, leaving the stems up for the winter aids in overwintering. The foliage helps to insulate the crowns. Mums seem to benefit a great deal from this practice. Another reason to leave stems standing is that if the perennial is a late riser in the spring, the stems will help to mark the spot and prevent any accidental digging in the area that might harm the underground portions of the plant.

Cutting back perennials in the fall may be something you would want to do especially if you were bothered by foliage diseases. Removing the old foliage would be a positive in this case, as it helps to reduce the amount of disease present to infect next year's foliage. Removing foliage can also be one of pure aesthetics. Some gardeners like to see standing perennials in the winter and others don't.

When perennials are cut down, do so after they have gone dormant. This is usually after the plants have experienced several hard frosts. The severe freeze took care of that for us. Cut the plants down to within 2-3 inches of the crown. Cutting too close can result in winter injury on some perennials due to the fact the buds for next year's growth are right at or above the surface.

Remember, mulches help keep temperature and moisture conditions more stable. Mulching after the ground is frozen will keep mulched plants dormant for a longer period of time. A depth of 2 to 4 inches is sufficient. Materials may be anything, but the best ones will not pack and smother. Oak leaves are great, while silver maple leaves are not. Straw also works well. If you have problems with mulch being blown off the area, you can make a short enclosure of chicken wire, hardware cloth or any other material.

As mentioned in an earlier column, take advantage of unfrozen ground to provide moisture for all perennials as needed. Rain or wet snow can provide the moisture, but usually the weather is dry enough to have benefit from some added water. Evergreens are particularly sensitive to drying out during the winter months.

Last column for the season

This will be the last regular offering for the season. There will be some updates posted in the "In The Backyard" blog on our Web page at www.extension.uiuc.edu/logan.

I've enjoyed providing the column again this year.

I'll close with some of the folk tales of winter weather prediction. One of the most famous refers to the woolly bear caterpillar. The longer the black bands on the banded woolly bear indicates a more severe winter. The woolly bear has 13 body segments and these correspond with the 13 weeks of winter. The head, of course, is the beginning of winter. Squirrels burying more nuts than usual, thicker fur on a rabbit's foot and more fall spiders than usual are also signs of a bad winter.

Of course hindsight is 20/20, and there will still be very cold days even in a mild winter. I hope you enjoy your winter, however it turns out, and I'll be back with you on a regular basis as spring approaches.

[By JOHN FULTON, University of Illinois Extension, Logan County]