JOHN CRETTI: THE BENEFITS of MULCH plus GARDENING TIPS
John Cretti’s Gardening with an ALTITUDE
The Benefits of Mulch
Hot summer weather has its good and bad side in my garden. Heat is needed for the production of the tomato crop and abundance of zucchini. Hot weather woes bring on the spider mites and the cool season vegetables start to wane. It’s a time to cope and think water conservation and maintaining uniform moisture availability to the vegetable and flower garden.
- It’s time to be sure that summer mulches are in place. I’ve tried a variety of mulching materials from the synthetic fabrics, colored plastics, cocoa hulls, and others. My favorites are still the organic mulches including unfinished compost, clean wheat straw, shredded cedar, and even pine needles. Proper use of organic mulch can help to reduce soil moisture loss by up to 70 percent. Plus, the insulating ability of mulch helps keep the soil cooler in summer and warmer in winter.
- In the tomato patch, mulches reduce rain and irrigation splash on the foliage, which helps to greatly reduce the spread of leaf diseases and discourages insect pests. For the organic gardener, cedar and redwood shavings can help to discourage slugs in the garden. A proper mulch barrier makes it more difficult for disease spores of powdery mildew and rust to get to the plant foliage.
- Another important reason to mulch is to suppress weed invasions, particularly the annual weeds like spurge, barnyard grass, foxtail, and purslane. I try to apply at least a two-inch layer of straw or dried grass clippings around tomatoes to choke out weed seedlings and prevent them from seeing the light of day. If some weeds do by chance get through the mulch layer, they are easier to pull out from the mulch layers.
- If you’re like me and have access to the many pine needles that shed in late summer and fall, collect them and use as mulch. Though there is a concern that these can be a fire hazard, use common sense in placing them around your plants and combine them with some compost. Pine needles from the Austrian, Scotch, and Ponderosa pines are great as they knit together and are more wind resistant than bark chips. The concern that pine needles cause the soil to become acid is a myth, it takes many years of heavy accumulations of pine needles to break down and even appreciably change the soil pH. As the needles decompose and turn into a crumbly organic material, feel free to work it back into the soil to enhance soil structure and retain soil moisture.
- The leaves in your landscape are perhaps the least expensive mulch, but they can come with some disadvantage. Some leaves are difficult to apply evenly; for example, cottonwood and other waxy leaves mat together and take years to decompose. Shredding leaves before using them as mulch is helpful and will expedite their decomposition for soil conditioning later on.
- As organic mulches breakdown and decay, they form a rich, dark organic soil amendment called humus. This eventually releases nutrients, enhances the ability for micronutrients to be released, and improves soil structure.
- Summer is the season of mulching. The idea is to apply a protective layer around plants to reduce evaporation, prevent erosion, maintain even soil temperatures, reduce the invasion of weeds, and in the case of organic mulches, enrich the soil.
GARDEN REMINDERS
Be Patient with Peppers
Peppers and tomatoes can be fussy when temperatures get over 90 degrees. They will often stop setting fruit. Be patient and keep watering deeply. Mulch to keep soil moisture uniform around the plants.
Harvest Zucchini Frequently
Keep your zucchini and other summer squash producing by harvesting the young squash every few days or as soon as they are 6 to 7 inches. This will encourage the plant to produce more blooms and more squash. Small squash are more tender and don't have hard seeds.
Plant For a Fall Crop
Now is the time to plant more beets, bush beans, kale, collards, leaf lettuce, radishes, turnips, chard and spinach for a fall harvest. These vegetables do well as the temperatures cool and have plenty of time to mature for fresh eating.
Wage Biological Warfare
Dust or spray Bt (Bacillus thuringiensis) if you see signs of attack from tomato hornworms or cabbageworms on cabbage. broccoli, and cauliflower. This is lethal to these caterpillars but does not harm the beneficial insects in your garden.
Keep Weeds at Bay
Don’t let up on the battle of weeds. Try to prevent growing weeds from developing seed heads. Even the task of breaking off flower heads will help reduce future invasions of weeds next year. Dig and hand pull weeds after a good rain or deep irrigation.
For more timely garden tips please refer to my book: MONTH-BY-MONTH ROCKY MOUNTAIN GARDEN GUIDE (Cool Springs Press). This book highlights what to do each month to have a healthy and beautiful garden all year.