October garden checklist

UNIVERSITY OF MINNESOTA EXTENSION - www.extension.umn.edu

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Mystery of the month

There is an interesting pattern of dark green spots scattered throughout the lawn of this boulevard. What may have caused this?

The solution is at the bottom of this article.

Pests and diseases

Remove diseased stems and flowers from your edible and ornamental plants. Properly managing plant diseases in the home garden this year can lessen the presence of some pests and diseases next year.

Trees and shrubs

Mark branches that need to be removed over the winter by tying marking tape loosely around the branches. This will help you identify the correct limbs to remove in a few months.

Read more about pruning trees and shrubs.

Flowers and other garden plants

Harvest most fruit from your annual plants before the first forecasted frost. 

Some fruit, like tomatoes, may continue to ripen indoors, whereas other fruit, like peppers, will stop ripening once harvested. 

Winter squash and pumpkins need to be cured for long-term storage. 

Read more about the best practices for postharvest handling of fruit and vegetable crops in Minnesota.

Houseplants

Set your houseplants up for success this winter by putting them in areas that match their ideal growing requirements. Light, temperature, humidity, and air flow are four key factors to consider for all plants. 

Some hardier houseplants can tolerate lower temperatures; placing them near windows, but not directly touching them, is likely okay. Other plants can be severely damaged if temperatures drop below 50°F, which happens against poorly insulated windows during the winter months.

Light is a significant consideration when moving plants from outdoors to indoors. We list some common houseplants along with their respective ideal light levels on the Lighting for indoor plants and seed starting page.

Lawn

October is the last chance to prepare the lawn for the entire next year. Fall, in general, is the best time to promote a dense and healthy turf that is more resilient and functional, and proper fertilization is the single most effective practice to accomplish these features.

Fertilization can occur in early October, but it may not necessarily benefit summer annual broadleaf or grassy weeds. If perennial broadleaf weeds are present and undesired, October is the best time to manage them by spot treating with selective herbicides.

By combining fertilization with weed management strategies, you can promote a dense and healthy turf that is more resistant to weed encroachment next year.

Other tasks

Protect any tender perennials as the temperatures drop later in the month. Roses can benefit from a thick layer of leaves or mulch.

Strawberries can be damaged once temperatures drop below 12°F. Straw mulch insulates better than leaves, although both are superior to leaving the plants exposed. You can follow our general guidelines for adding and removing straw mulch for strawberries.

Solution to the mystery of the month

The boulevard on the right was not fertilized in the same way as the rest of the lawn on the left side of the sidewalk.

The darker green spots, surrounded by yellow-green or chlorotic turf, indicate low nitrogen levels in this boulevard. In this case, the nitrogen from dog urine has fertilized these spots.

Fall is the best time of year for fertilizing lawns in Minnesota.