October 3, 2001
Stillwater Gazette
Betsy Halden

Fall care for lawns and gardens

In the aftermath of our national events, people seem to be settling in, going back to work. There is comfort in being with friends, in performing the familiar. And many of us find comfort in working in our gardens. As I write this, today is a perfect early fall day. The sky is cloudless blue, the temperature is in the 60’s. Just about perfect. It’s a joy to be outside in the garden. My roses are still blooming. The seed dahlias, snapdragons, cleome,marigolds, and chrysanthemums are covered with blooms. The late-blooming hydrangea has a white flower unfolding. But things are about to change. The big sunflower had a touch of frost this week. We know cool weather is on the way. It’s time to get ready for fall. Here are some tips for your fall lawn and garden work.

“Now is the time to give your lawn attention and care,” according to Deb Brown, University of Minnesota Extension horticulturist. “After applying lawn fertilizer around Labor Day, the important thing is to make a second application of fertilizer in mid to late October. Even though cooler temperatures slow grass top growth, the soil remains warm enough for root growth. Late fall fertilization encourages root growth. This results in grass coming back thicker and greening up earlier next spring.”

Nancy Davis, horticulturist for Park Nursery in Stillwater says, “Grasses grow best when the weather is cool. Fall is the best time to feed lawns. Fertilizing lawns in fall helps to make healthy lawns lush, thick, dense. Garden centers may call fall lawn fertilizers ‘winterizers’.” After applying the fertilizer, water your lawn well. Lawns and plants need a generous amount of water in the fall to carry them through the winter.

Before fertilizing your lawn, you probably will want to rake the leaves from the grass. This will enable the fertilizer to reach the soil easily. If you have only a light cover of leaves, you can run your lawn mower over them a couple of times to chop the up and allow them to filter down through the blades of grass.

Lawns should be mowed to a height of 1 ½ to 2 inches in the fall. If the grass is mowed too short it is vulnerable to winter injury if snow melts off and temperatures drop suddenly. If the grass is too long it can encourage growth of snow mold.

Mid-October is not the time to use weed killers on your lawn. Broadleaf weed killers are more effective when applied in the early fall or in the spring. Pre-emergent herbicides can be applied around the end of April or the first of May, after the temperatures have warmed. Local garden centers as well as the Yard & Garden Line can give reminders about the dates.

Now is the time to plant spring-flowering bulbs. Local garden centers offer wonderful selections. I like to browse and find new varieties. After deciding where you want to place your bulbs, dig the hole 2” deeper than the hole depth recommended on the bulb packet. Add a little bulb food or fertilizer, stir it up with the dirt, add the bulb, pointy end up, and fill the hole with soil. Avoid allowing the bulb to come into direct contact with the bulb fertilizer.

Now is the time to divide and transplant spring or early summer-blooming perennials. Peonies, daylilies, iris can be transplanted now. Be sure to water the plants well after transplanting. This is also an opportunity to add well-cooked compost, perhaps sphagnum moss, to the soil. Soils need fibrous materials to keep the soil porous and loose.

If you are considering planting other deciduous woody shrubs or evergreens this fall, do it soon. The longer the newly planted plant is in the ground before the soil freezes, the better chance it has of establishing its root system. The stronger the root system, the better the chances are for the plant to survivie the winter. Be sure to water well all newly planted materials.

Now is also the time to clean up vegetable and flower gardens. Remove fallen leaves and vegetative debris. Pull and compost frost-bitten annuals. Remove dead and spent perennial blooms. Dispose of dried tomato and other vegetable plants. Rake up and remove dead leaves in the garden. Remove dead or diseased leaves around rose bushes if you have had rose black spot disease. The disease can overwinter in the soil and affect the plants next year. These good cultural practices can help to maintain healthy gardens next season.

Hardy Minnesota chrysanthemums may keep blooming if we avoid a deep killing frost. Nancy Davis recommends trimming only the blooms of the hardy mums. She likes to leave the stems on the plants. Not only do the stems store food, they also catch snow which helps to insulate the plant. The dead stems can be snipped off in the spring.

Finally, mulch and water the garden. Theoretically, mulch can or should be applied after the ground freezes. This helps to deter critters from burrowing under the soil and mulch and eating the roots of favorite plants. But many gardeners put their leaves on the garden beds. Mulch helps to stabilize soil temperatures and moisture. When the soil freezes and then thaws, plants may be heaved out of the ground. A good snow cover can help insulate the garden. Somehow applying a good mulch makes me feel as if my garden has been properly cared for. It’s also a good reason to be outside and to enjoy the fall every day we can.

Betsy Halden is a Master Gardener with the University of Minnesota Extension Service. University of Minnesota Extension Service materials were consulted in the preparation of this column. You can reach Betsy Halden at eahalden@comcast.net