By Lili Michaud
Lili Michaud is a French-Canadian urban agronomist, garden coach and author of six books. Recognized for her professionalism, objectivity and communication skills, Lili Michaud has solid expertise in urban ecological practices and growing edible plants.
Unless you only grow cacti—and that would be unfortunate, wouldn’t it? —, it’s in your best interest to use compost in multiple ways throughout the garden. And for good reason, as the positive effects of compost on the soil and plants are numerous. In fact, compost:
- nourishes the soil and thus indirectly the plants that grow there, thanks to work carried out by earthworms and soil micro-organisms;
- increases the soil’s capacity to retain water and minerals, a characteristic particularly important in the case of soils largely composed of sand;
- improves the structure of clay soils, making them very suitable for the cultivation of all plants, even root vegetables;
- helps to bring soils into a more acceptable pH range, much to the benefit of most edible plants and soil organisms;
- increases soil’s resistance to compaction, erosion and leaching;
- helps maintain healthy plants. And we all like healthy plants, don’t we!
Which is Better: Homemade or Commercial Compost?
I clearly can’t stress enough the “eco-friendly” benefits of making your own compost if you have the chance. Seeing waste transform before our eyes into a real “brown gold” (as compost is often called) remains a rewarding activity from all points of view. In addition, making your own is the best way to control the quality of the final product. But if that’s not possible, commercial compost is certainly a good product you can use as a substitute.
Compost in the vegetable garden
Did you know that some vegetable plants really thrive when you supply them with compost while others don’t really benefit all that much from it? So, let’s classify vegetables according to their requirements.
Tomatoes, cucumbers, squash and corn are the true compost lovers, while peppers, carrots, and lettuce have a more average appetite. Finally, beans and peas are very frugal plants and can often get along without it. Thus, depending on the requirements of the vegetables you grow and the quality of the soil in place, the need to add compost in the spring can vary from zero (in the case of a bean crop in rich soil) up to working in 2 inches/5 cm of compost (for tomatoes on very poor soil).
Once the vegetable bed is ready, apply a top dressing of compost, then incorporate it into the upper few inches (5 cm) of soil with a garden claw or rake. For more demanding plants like tomatoes, add a cup of compost directly to the planting hole.
Compost in Perennial Flower Gardens
Apply compost to a new flower garden, still bare of plants, in the same way as you’d add it to a vegetable garden, by top-dressing, then working it in. For already established beds, simply side dress, that is, apply compost between the plants in the spring, then cover it with mulch. Depending on the type of mulch and the requirement of the plants, you may need to side dress with compost every year or two.
Compost in the Lawn
Compost restores vigor to all lawns, but especially those whose soil has been disturbed by the use of pesticides or synthetic fertilizers. The operation, called top dressing, can be carried out in the spring or fall, ideally before a rain. It consists of applying a thin layer of compost (1/8 to 1/4 inch/0.25 to 0.5 cm) over the lawn’s surface. You can hand broadcast it or you could rent a top dresser (soil spreader). Next, rake the lawn to distribute the compost more evenly and pull the blades of grass back into an upright position.
Compost for Trees and Shrubs
You can include compost when planting trees and shrubs at the rate of one part compost to two parts soil or spread it over the soil as a top-dressing, just before adding mulch, as you finish the planting.
Container garden maintained with compost
Gardening in Containers
Whether you buy potting soil for container cultivation or prepare your own, make sure it contains compost, especially if you’ll be growing vegetables. And in future years, you can revitalize the potting soil and use it over and over by mixing in 1/4 to 1/3 compost.
Compost Tea … a Little Summer Pick-me-up
Although compost remains the basis of fertilization, some crops benefit from a bit of extra “feeding” when they undergo their summer growth spurt … a bit like a human teenager! This is especially the case with the more demanding vegetables: tomatoes, squashes and their ilk. One way to get them the extra minerals they need is to apply compost tea.
Here’s an easy recipe for making your own compost tea:
- let one part compost macerate in two parts water for two to three days;
- stir daily, then cover;
- roughly filter the resulting tea to remove solids before applying;
- apply compost tea by watering it into the soil at the base of the plants.
Compost: it really is essential to gardeners. Learn how to use it well!
Photos supplied by Lili Michaud.