To mulch or not to mulch

I’m a big advocate of adding mulch to your garden. If we didn’t use mulch, we could never keep up with the weeds, especially with the large-sized gardens I have in my yard.
We mulch around the fruit trees with bark (or you could use wood chips) to keep the sucker and weed growth to a minimum while making mowing around the tree much easier.
We mulch the perennial beds with pine bark to conserve soil moisture and minimize weeds.
As far as adding mulch to the vegetable garden, I’ve done quite a few experiments over the years and still haven’t come up with a totally foolproof solution to date, but will recommend some things for you to try in a future column.
There are many factors to consider when determining which garden mulch or landscape mulches are best suited for your landscaping needs.
Mulch, when installed and maintained properly, can provide a great deal of aesthetic quality to the overall look of your yard and garden.
Not only will it help you to reduce your watering and maintenance chores, but it will provide a finished look to your gardens and help them to maintain an overall neater appearance.
Garden mulch can be directly related to plant health, specifically through its effect on the composition of soil pH. Since organic garden mulch influences that composition as it decomposes, your first decision will be based on the pH requirements of your soil.
The pH requirements in you garden can vary from area to area, depending on what you are growing in your garden and the type of soil that you have.
Keep in mind that pine needle mulch and some bark-based mulches are best used around acid-loving plants like evergreens and rhododendrons.
If you use these landscape mulches around plants that crave alkaline soil, don’t forget you will need to sweeten the soil annually by adding some powdered lime.
There are many other mulch products, both organic and inorganic, suitable for both acid-lovers and plants that prefer a basic or neutral soils.
Beyond the initial consideration of effects on soil pH, the gardener needs to determine the type of mulch wanted based on the effects they want the mulch to produce.
Other factors to take into consideration when choosing a mulch product are maintenance requirements, costs, aesthetics, availability, ease of installation, and personal preference.
Furthermore, the gardener will have to weigh all the pros and cons of each type of mulch before making a decision on which to use. Remember that any organic mulch product needs to be somewhat loose in texture to allow water to penetrate and air to circulate.
The two most obvious uses of garden mulch are weed suppression and erosion control. Almost every garden mulch product available, if installed properly, will cut down on weed growth and prevent erosion.
Mulches influence moisture penetration in a few ways. Bulky materials, such as bark, wood chips, sawdust, and straw, temporarily hold a fair amount of volume of water, and thus prevent loss of soil by run-off when the intensity of the water is too rapid for soil penetration.
This may be more important with a heavy silt or clay soil than with a porous, sandy soil.
Rain beating on exposed soil can compact it, and subsequent baking in the sun almost completely gets rid of its capacity to absorb water rapidly.
The open soil structure found under mulch is favourable to a more rapid air exchange, allowing the roots access to the required oxygen for the respiration process, through which energy for growth is released.
Mulch also can provide protection from soil-borne plant diseases by preventing the soil containing disease spores from splashing onto leaves.
As well, mulch has the ability to provide an “insulation value in the summer.” This is judged by the degree to which the garden mulch product can keep the soil beneath cool and moist.
A successful summer insulator will protect roots against extreme heat, and can reduce the need for watering by keeping the soils moister longer than if unprotected.
Mulch also provides a layer of insulation and protection for plant roots in the early spring. Once the snow layer has melted away, the layer of mulch helps the soils to warm up at a more constant rate than if left unprotected.
This prevents a rapid thaw and then the roots of plants from freezing if a “cold snap” happens. A good layer of mulch also can help to prevent frost heaving in the spring of shrubs or perennials.
Organic mulches also supply humus as they gradually break down, providing a decomposed organic material that supplies necessary nutrients for the cycle of soil life and the organisms (like worms) that proliferate in healthy soils.
This process of decay can add extra nutrients to your garden, but also be aware that during the decay process, some organic mulch products can “lock up” nutrients in the decay process.
The key message here is not to forget about applying fertilizer to your garden after you apply a mulch product. The type of fertilizer needed will depend on the nutrient requirements of your soil and the type of mulch product you have installed.
If you are installing a perennial bed or a bed of ornamental shrubs, you will want to consider mulching the bed. I do recommend that if your garden is a work in progress, that you think about the type of mulch product you want to install.
You may consider two different product: one for the short-term (while the garden is under construction) and then one to install later with a more “permanent” intent.