When I think about spring, I always think about planting. It is fun, stress relieving, and rewarding for me to get my hands dirty and plant some new plants or change what I have in my garden. One thing to always remember when planting a garden or cleaning up an existing one is the mulch.
Mulch is a great benefit to our plants. Mulch can help work as insulation for our plants through the winter months, protect them from lawnmower blight, hold moisture near the plants, and reduce weed competition.
In the winter months, mulch is helpful to keep our plants insulated from freezing temperatures. However, mulch does not necessarily keep the roots of the plants warm, it keeps the temperatures from constantly freezing and thawing. In the winter months, freezing and thawing of the soil can push the plant out of the soil in a condition called frost heaving. This can expose the crown to winter temperatures and possibly kill the plant. We often add extra mulch during the winter months to help protect our plants more. The plants then are adjusted to growing in the conditions under the extra mulch, which is why it is important to wait to uncover them for the spring. If the plants start to green up under the mulch or pop through the mulch you can pull the mulch back away from the plants, leaving it nearby to cover the plants back up if freezing temperatures are predicted again. It is best to wait until early May to fully uncover those plants, once the threat of frost has passed for the year.
Mulch also helps protect our plants from a condition we refer to as ‘lawnmower blight’. Lawnmower blight often occurs to our trees and shrubs growing right in the turf with no mulch around them. It is when the mower or weed trimmer gets too close to plants damaging the trunk or branches of the shrub. This damage disrupts the flow of water and nutrients through the tree, but it usually does not kill the plant. Having the mulch ring will keep the lawn equipment back away from the tree.
Mulch is also great for our plants during the spring and summer months to help keep moisture near the plant and reduce competition from other plants around the tree or other desired plants. Wood chips will hold moisture that will eventually be released back out to the plants for extended water availability. The layer of mulch will also help reduce competition for water, nutrients, and space from other plants growing nearby. Turf is included as a competition for our landscape plants. It is best for the overall health of our desired plants to keep the competition limited around the roots.
Mulch needs to be applied correctly to help the plants, if applied incorrectly it can damage them. A layer of mulch 2-3 inches deep is the recommendation. Too deep and you can start to starve the roots of oxygen and the roots may begin to grow in the mulch out of the soil. If the mulch is applied to shallow, weeds will come up through it. Avoid mulch volcanoes which can cause a great deal of damage to the plant. Coarse textured mulches are better for plants than fine textured mulches which can become compacted, reduce oxygen to the plants, and allow more weeds to penetrate.
Organic mulches are preferred over inorganic mulches. Organic mulches would include wood chips, straw, leaves, and untreated grass clippings. Inorganic mulches such as rock or crushed rubber would not give the benefits to plants that organic mulches would. Inorganic mulches do not hold onto water and they make the plants and the roots much hotter in the summer and reflect that heat onto the plant causing more drought and heat stress to the plants. Inorganic mulches would be best used in xeric landscapes and rock gardens.