Putting your vegetable garden to bed: 4 things to do before winter

1. Clean the leftover plant parts

After the first deadly frost, it’s time to remove annual plants from the garden. Not only is this debris unsightly, it can potentially add to disease problems for the next year. For example, two common tomato fungal diseases – late blight and Septoria leaf blotch – overwinter in the soil of crop residues. Raising and disposing of all parts of infected plants will help reduce infection in the following season, especially in small gardens that don’t have much crop rotation opportunities.

Remember to compost only plants that are not diseased, as some pathogens will not die when composted.

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2. Perform a soil test

Fall is a good time to do a soil test. Soil tests will show if there are problems in the soil, such as a lack of nutrients, low organic matter, or high pH that could limit your vegetable growth for the next year.

The sampling now leaves enough time to make all the necessary changes to the garden in autumn or next spring so that your garden is ready for success in the next year.

Soil is unique from location to location, so we shouldn’t assume that it has everything we need for a successful harvest. Dumping too little or too much fertilizer can be harmful in their own way, so do a soil test to remove the guesswork.

Wondering how to do a soil test? To use the University of Minnesota soil test lab, go to https://soiltest.cfans.umn.edu/ or call the Hubbard County Extension Office for more information and instructions at 732-3391.

3. Apply soil conditioners

Gardeners have many options when it comes to vegetable gardening supplements, including compost, manure, and granular fertilizers.

Granular fertilizers are a relatively accurate way of meeting the needs identified by the soil test. They have set nutrient levels, and those levels are stated on the product label. Your soil test report will indicate what concentration is recommended for your garden based on the results.

Since we have very sandy soils in our area, I wouldn’t recommend fertilizing with readily available nitrogen in the fall, as plant-available nitrogen can be washed out of the soil before your plants need it the next spring and summer. The addition of phosphorus, potassium or micronutrients can be beneficial in autumn so that the nutrients are available when they are needed.

4. Fight weeds

The two main goals of autumn weed control are removing any leftover mature weeds and controlling annual winter weeds that emerged in September.

Weeds that slipped between the cracks and grown to maturity over the course of the season now have seeds on them. Many of our common weed species can produce between 1,000 and 600,000 seeds per plant. If you drop these seeds on the garden soil, it will lead to future weed infestation. Remove mature weeds as soon as possible and dispose of them.

Annual winter weeds are those that appear in the fall (August-October), survive the winter, and continue to grow in the spring. Fighting it in the fall results in fewer weeds in the spring. Manage winter annuals with straw, hand pulling and gentle raking of the soil surface.

What about tillage?

Plowing your vegetable garden in the fall may not really be necessary.

Many gardeners may plow or hoe with the best of intentions in the fall, but doing so could unnecessarily disrupt soil structure and valuable soil organisms, and make the soil more prone to erosion.

When plowing (or hoeing) soil improvers and plant residues are incorporated, weeds are killed and large lumps of soil are broken up. If you don’t incorporate soil improvers, you can do without tillage this fall.

Weeds can be controlled by pulling by hand, covering the ground with straw to suppress new weeds, or raking the surface to remove small weed seedlings.

If you do these chores in the fall, your garden can start on the right foot in the spring and save you time and frustration the next spring.

If you have any questions on this or any other topic, please contact me at 732-3391.

For information on agriculture, gardening, and natural resources, subscribe to the Hubbard County UMN Extension’s Agriculture, Gardening, and Natural Resources e-newsletter at z.umn.edu/HCExtensionNewsletter.

Tarah Young is an interim agriculture, food, and natural resource instructor with the Hubbard County University of Minnesota Extension.

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