Preparing Your Landscape for Winter

Preparing Your Landscape for Winter

Brian Jervis: Ask a Master Gardener

Tuesday, November 21, 2017

Q: While the main growing season is over, there must be some things that I can do to prepare my landscape plantings for winter. What are some of the things that I should and should not be doing? Lisa M., Tulsa

A: The average winter temperatures we experience are normally not sufficient to cause extensive winterkill in established plants rated for our hardiness zone (6b to 7). Most plants that do suffer from weather stress are unhealthy to begin with or are simply unsuited for our environment.

If you have been fertilizing over the summer, now is the time to taper off. Hardy plants like trees, shrubs and perennials need to be allowed to go dormant. Fertilizing at this stage may cause a delay in this process and may encourage tender new growth that is especially susceptible to freeze damage. If plants appear weak or a soil test shows serious nutrient deficiencies, wait until after a frost to do any correction. Always follow label instructions and water well.

Pruning should also be kept to a minimum when you are prepping your landscape for winter. Not only can pruning stimulate unwanted new growth, but also in many spring-blooming plants, you will be removing next season’s buds. In addition, you will remove some of the energy that plants made in summer and have stored for winter use. It is perfectly acceptable to cut out any dead or diseased wood, and you should remove all debris from around plantings, thus discouraging any overwintering pests or rodents.

Lack of moisture is a major cause of winter stress for plants. It’s important to keep up with a watering schedule, especially if we are not experiencing timely rains. Longer, deeper watering is always recommended over frequent, shallow watering. You want to get moisture down below any frozen ground. Don’t overlook container plants or plants under eaves that won’t benefit from rains or snow.

And don’t forget the mulch. Not only will a good layer of mulch protect stems and roots from freeze damage, but also it will help moderate soil temperature and moisture. The key is not to mulch too early. Wait until after the first killing frost to lay any additional mulch. And when placing mulch, take care not to pile it around and next to tree trunks and stems as this can cause unnecessary damage. If your roses have not been mulched, do so now. This is a good place to use those fall leaves that have been shredded with a mulching mower. Mulch not only prevents cold damage to susceptible plants, but also will prevent warming of soil on warm winter days, which may promote premature cold-sensitive new growth.

Another consideration is to leave last year’s plants that have seeds on them (such as the purple coneflower) in place until spring. Coneflowers have seed heads that finches love to feed on in winter.

Finally, don’t forget to keep the compost pile watered. The decay process to produce garden-friendly compost continues into the winter if the pile is large enough and kept watered and turned.

Garden tips

• Fertilize cool-season grasses like fescue with 1 pound nitrogen per 1,000 square feet. This should be the last fertilization for fescue until next spring. Do not fertilize Bermuda or Zoysia until green-up next April.
• Spring-flowering bulbs like hyacinth, narcissus and tulip, which are sold for “forcing,” can be potted in indoors for a colorful winter display.
• Tulips can still be planted outdoors through this month.
• Autumn leaves have good uses other than placing them in the trash. They may be mowed directly into the lawn, which will add nutrients and organic matter; shredded with a lawnmower and added to the compost pile; used as mulch or tilled into the soil of your garden beds.