I have a perennial garden with lots of flowers and grasses. It seems everybody has a different opinion as to when to clean up the garden. Some say wait until spring and others say do it now. What is best and why?
The best time for a perennial garden cleanup is spring. But if you had diseased plants, like peonies with black and purple spotted leaves, remove that material now when you can find it.
Many of the “fungally challenged” plants will be infected again next year from this year’s diseased leaves. Remove that material and burn or bury it. It will come back to haunt you if you put in the compost pile.
The reason for spring cleanup is that all those dead stems act as free snow fences for the garden. Snow blows in and stays. No matter how cold it gets, it will be a lovely 32 degrees below the snow. This protects the roots from most potential winter damage. This is why snow in the garden is called poor man’s mulch by many old time gardeners.
Snow does a great job of keeping soil frozen instead of the deadly freeze-and-thaw cycle that makes up a portion of many winters. If you have heavy soil, the freezing and expanding then thawing and shrinking can eject poorly rooted plants right out of the ground. Hosta leaves collapse like faulty umbrellas over the crown of the plant, protecting it. Tops left on plants can also act as markers so if kiddies are cross country skiing or dragging sleds around, they know here to stay away from.
If you have plants or grasses with seeds on the top, many small birds will supplement their winter diet with these. So this fall, remove any diseased plant tops, touch up weeding if there are invaders to remove and replenish mulch so the soil is covered with two to three inches of something organic.
I have some little evergreens that I bought as seedlings a few years ago. I put them in an area so they would be easy to care for. They are now about two to three feet tall and I want to move them. I want to do this now but my wife says to wait until spring. So who’s right? What do I fertilize them with?
This one goes to your wife. Any time you have a choice between spring or fall to move evergreens, spring works better.
When you transplant an evergreen, you will disrupt roots. The larger the tree, the more that is possible because of the weight and volume of soil. The roots that most often are damaged are the tiny feeder roots that are thinner than a hair. These are the important little guys that take in moisture and nutrients.
In the fall, there is very little or no time for the tree to repair damage. This includes both pruning damage and root damage. The soil is cooling off and root growth slows and stops. Often, the fall transplants show wind burn or brown needles in the spring. The feeder roots had no time to repair and not enough moisture was pulled up into the needles.
Winter wind whipping over needles sucks the moisture right out. That can happen with both warm and cold winds. Putting up a burlap fence can help some but often, evergreens still look dried out.
In the spring, evergreens can be moved as soon as the ground has thawed. If you mulch and keep them watered, they have the entire growing season to work on repairs.
If you feel the need to fertilize, the best choice would be to get a soil test to find out what’s missing. Don’t use the nitrogen recommendation for the first year, but if there are phosphorus, potassium, sulfur or lime recommendations, use those. Nitrogen has the ability to burn roots and this is not the time when you want any root damage.
Contact Gretchen Voyle, MSU Extension-Livingston County Horticulture Educator, at (517) 546-3950.