by David Salman
Now that it’s officially summer, and the heat has arrived, we’re all looking for ways to stay cool. Well your garden plants are feeling the same way. And that’s where putting a blanket down can help; a blanket of mulch. Mulching is a well practiced gardening technique of covering the soil with some type of plant derived or mineral material. Mulching provides your garden and landscape with a multitude of benefits including;
- “dressing up” your plantings to give them a neat, finished look,
- keeping the soil shaded and cool for optimum root growth,
- conserving the soil’s moisture by protecting it from the sun and drying winds,
- adding invaluable organic matter to the soil to improve its fertility and water penetration and
- keeping down the weeds.
With the sun high overhead and the hot daytime temperatures, well mulched plants will grow faster, be healthier and flower more profusely. By covering the soil with a 1 to 2” layer of mulch, the soil stays moister longer and the soil temperature stays optimum for roots to stay actively growing.
There are a wide range of choices of materials for use as mulch. And you may actually choose more than one type depending on your garden’s needs.
- For vegetable gardens, clean wheat or barley straw is the best. It just takes a few bales spread out over the whole surface of the garden. Putting down the straw in a 2 inches thick layer will help your veggies to grow better and provide a non-muddy walking surface in the aisles while keeping your veggies clean and out of contact with the soil. (Important for squash, melons and tomatoes.)
- For your trees, shrubs and flower beds, plant derived materials like shredded bark and crushed pecan shells are both decorative and effective. Coarse textured composted cotton burrs are another Southwest regional favorite. Gravel is a superb mineral-type mulch and works best when used at a sufficient depth of at least 1½ to 2 inches. Use smaller 3/8 to ½ inch diameter crushed (angular) rock for best results. And gravel mulch is a great choice for water harvesting as it gives hard rains a chance to soak in instead of flowing across hard packed soil.
- Weed barrier (Geotextile) cloth is not something I recommend. It is commonly put down underneath the mulch. But the weed barrier makes it difficult to plant more plants into the area, and you can’t use compost and non-liquid natural fertilizers to enrich the soil. They need contact with the soil surface to breakdown and release their nutrients.
Mulch materials are most commonly sold in bags and in bulk (by the pick-up truck load). As a general rule of thumb 1 cu. yd. of mulch covers 200 sq. ft., 2 inches thick. Many types of mulch are sold in a 2 cu. ft. bag which will cover approximately 12 sq. ft. spread 2 inches thick.
Of course, if you haven’t mulched yet, your plants are pleading with you to get it done now. Normally landscape professionals recommend a late spring (May) application followed by a “touch up” in late fall (October/November) by adding additional mulch to bring it up to sufficient depth. This tucks your plants in for the winter by insulating the soil to keep it warmer and roots actively growing. Later, with the coming of spring, it keeps the soil cold and prevents your plants from waking too early and getting nipped by late spring frosts!