For the most effective results, before applying any mulch to a bed for the 1st time, cover the ground with cardboard or thick layers of newspaper to block the light. Overlap your material, leaving no bare ground exposed. Coarse textured mulches can be applied up to 4" deep; fine-textured mulches only need to be applied up to 2", since they pack more closely.
You'll need to replenish your mulch periodically because it will decompose over time. But once you have an established mulch layer, you won't need to lay newspaper or cardboard again.
Here are a few tips:
- When using drip irrigation, lay the newspaper or cardboard under the drip tubing, making it easily accessible.
- If you want to add plants after carefully covering your garden with newspaper and cardboard, don't despair! Push aside the mulch, expose the paper, and cut an "X" large enough to accommodate your plant. Fold back the flaps, dig a hole, and add your plant. When done, lay the flaps back in place and re-cover your plant with mulch.
- One caution: when mulching plants with woody stems, especially trees, leave a couple of inches of bare earth around the trunks. Too much moisture around woody stems can rot them.
In the case of plant-based mulches, you can use the seasons to your advantage by following these guidelines:
- Many seeds require warmer soil temperatures in order to germinate. Therefore, start adding mulch to newly planted beds in the late spring after the ground has warmed up a little.
- In established beds, you can add mulch earlier. By mulching as the winter rains taper, you can often delay watering plants for several weeks as the weather warms.
- Early summer is prime time to maximize your use of mulch.
- Over the summer months, your mulch will decompose and reduce in thickness, just in time to take advantage of the mid-fall rains.
- Allow your mulch to continue to decompose as winter rains increase. Plants need good drainage during these months.
How to decide what type of mulch is best for your garden? As you visit local nurseries and gardens, take note of what types of mulch are used. Determine which look you prefer and which fits the style of your garden the best. Ask your favorite nursery which material they use in their demonstration gardens and why. Experiment with a few bags of different materials to see which effect is most pleasing. You may decide to use different materials in different places in your garden. Whichever type you decide upon, however, nothing will benefit your garden quite like mulch. No longer will you be a slave to weeds! You can have a beautiful garden while still practicing water conservation. And, you can be steward of your land, protecting the soil and increasing its fertility over time.