The Willamette Valley, usually known for it’s darn near perfect summers—dry, breezy, in the eighties with cool nights—has seen two serious heat waves this summer. One came at the end of June, the second at the end of July. Both were problematic for crops, as they came right when many young transplants were settling into the fields. My own small scale fall and winter garden went in about four days before the second heat wave. How could I keep them alive in the blazing afternoon sun when their roots were not reaching deep into the soil? I mulched. First, I worked all of the residual mulch from the early potato crop into the bed. Then I nested each start in a base of straw mulch laid over the ground and soaker hoses. They all came through. Mulch. Straw, leaves, winter cover crops, cardboard or woodshavings … it’s useful stuff. Placed neatly around the base of young plants and later worked into the soil, it has a multitude of benefits.
1. Mulch keeps the weeds at bay. If the garden bed is thoroughly weeded before the mulch is laid down, the organic matter keeps new weed seeds from sprouting as quickly by blocking the light. And, when they do sprout, they are often more loosely attached to the soil and thus easy to pull.
2. Mulch maintains soil tilth and fertility. Mulch and compost alone will not provide all of the nutrients hungry plants need, but they do harbor many microorganisms that aid in nutrient exchange. Organic matter also holds water longer, which can reduce both run-off from a sudden rain and the need for frequent watering. Finally, it can protect soils from compaction during a winter of steady rains.
3. Mulch keeps water where it belongs, in the soil, not on the plants. If you use soaker hoses, covering them with handfuls of straw before the watering season begins helps keep the water on the ground, and in the garden bed, not in the pathway or on the plants. This reduces water waste and helps with plant health by not spreading diseases.
4. Mulch keeps the roots of you plants cool—twenty or thirty degrees cooler on mid-summer afternoons—by providing shade. Slide your hand under a mulched bed and then lay it on the path between the rows and notice the difference! When the weather is hot, this temperature differential can make the difference between a healthy plant and one that is covered by aphids or flea beetles.
5. Mulch helps control garden pests, both by keeping the plants healthier and by providing slow release nutrients to the garden. A healthy plant does not send out distress signals which call in destructive insects. Although some pests can lurk under the leaves, I have found the benefits outweigh the costs.
6. Mulch keeps the garden tidy. There are few things more satisfying than looking over a well-mulched garden, healthy green veggies poking up from under a blanket of new straw or leaf mulch, knowing that everything is right with the field.
It is late in the season to mulch summer crops, but it is the time to start looking around and considering ways to collect and add mulch to the garden beds for next year. Do you need to add another hoop to the compost area to collect leaves and allow them to rot down over the winter? Would a cover crop on several beds provide some early season mulching material? Is there a source of straw, or used bedding material, nearby? Keep your eyes open. Mulch — often free — is everywhere!
With great thanks to Nate at Sunbow Farm, who has been on a serious mulch study all summer long.
To read more about the Twenty First Street Urban Homestead, check out my blog at 21st Street Urban Homestead.
All MOTHER EARTH NEWS community bloggers have agreed to follow our Blogging Best Practices, and they are responsible for the accuracy of their posts. To learn more about the author of this post, click on the byline link at the top of the page.