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Mulching Tips

Mulching Tips

Mulching can be done in the Spring, Summer and Fall and serves different purposes during those times of the year. As well, propering mulching around trees and plants can help extend the life and health of the vegetation. Mulch can also be used for decoration to help dress up an ugly part of your landscape. Using mulch properly can increase soil moisture levels, minimize weeds, help control soil temperature and help with soil nutrition. Mulching is one of the best things you can do for the health of trees, shrubs and flowers. Some of the following things should be considered when mulching:

Mulching In Spring:

Most of the time mulching is done in the spring so that the mulch can help keep the moisture in the ground and help provide nutrients so that seedlings are able to establish. As well mulching in the spring will help protect perennials & bulbs in case there are some cold frosty nights. Typically your mulch depth should be 2-4″.

Mulching in the Summer:

Using mulch in the summer typically helps to keep moisture in the ground and at the same time the mulch keeps your roots cool. These are two important reasons for the health of the plants or trees/shrubs. One of the other big reasons to apply mulch in the summer is that it helps to inhibit weeds and weed growth. Typically your mulch depth should be 2-4″.

Mulching in the Fall:

Mulching in the fall generally takes place later in the fall to protect trees and plants from the winter. Typical mulching will occur after the first frost so that you can use the mulch as a blanket to help trap the frost in the ground. This will help to keep plants dormant, but will also help in the spring so that the buds do not open early. From a root perspective, mulching will help protect roots from heaving due to frost. Typically your mulch depth should be 2-4″.

Mulching around Trees:

Trees that are planted in well drained soil should be mulched to an approximate depth of 10cm (4″). Mulch should be kept a minimum of 4″-6″ away from the trunk of the tree to prevent the mulch from rotting the bark. Excessive mulch material piled up against the base of a tree or shrub forming a heap, keeps moisture in direct contact with the bark. The moisture penetrates the bark and begins decaying the tree/shrub which in turn hurts the supply of food to the tree or shrub. When this food supply is limited, the roots die and the tree will decline and eventually die prematurely. Most trees are normally mulched to a width of 12″-18″ around the tree. The wider (not deeper) the layer of mulch the more beneficial it will be. To correctly apply mulches, such as the common shredded pine, cedar or hemlock bark to trees, start 4-6 inches from the base working out to the desired diameter. Depth should start at 1-2 inches at the inner circle, increasing to no more than 4 inches (two inches for clay soils) at the outer edge of the circle. Final depth may be slightly reduced if a non woven landscape fabric is placed under the mulch.

If trees or shrubs have been mulched too heavily, remove excess mulch using a shovel or broom and avoid damaging the trunk of the tree or shrub. A hard stream of water may be used to remove excess mulch and soil from the trunk and base of the tree. Also keep in mind that trees planted in wet soils will need adequate oxygen and, therefore, less mulch should be used.

Mulching Around Plants:

Proper mulching is especially important for plants under stress, or newly planted ones without extensive root systems. You can lay non woven landscape fabric and make holes to plant the flowers. Landscape fabrics are not useful for perennials, except perhaps in the first year. Such materials are useful for annual flowers which will only be in one place for a year. Don’t cover perennials, or you may smother them. Just as thick mulch will prevent weeds, it will prevent these plants from growing too. Mulching your flowerbeds is an important operation that should be done every spring. Do not mulch perennial beds too early in the spring, you need to wait for the shoots to emerge. Remember to first remove any grass, weeds and dead plants from your planting beds. As well, install new plants before you apply your mulch layer.

General Tips

  • Uncomposted mulches such as pine bark, can take nutrients from the soil. To reduce this problem, spread an organic fertilizer on the soil before mulching.
  • If possible it is best to water before and after mulching. Mulching before or after a rainfall is also a good time.
  • Cover garden beds with a layer of mulch to keep weeds down and reduce the need for water. Annual weed seeds are less likely to sprout when the soil is covered with enough mulch to keep the soil surface in the dark.
  • Mulch provides a layer of insulation that helps prevent evaporation of moisture and deters weeds. It also protects your plants from extreme in temperature. Thicker mulch layers can reduce water use by as much as 50 percent.
  • Annual additions to mulch only should be made to maintain proper depth. Removal defeats one of the purposes of mulch, which is to decay and mix with the soil. Fluffing the old mulch, before adding more, will prevent it from forming a hard surface that deflects water, rather than retaining it.
  • Do not mulch too thick (i.e. more then 4″) as it will become too hard for the water to penetrate the mulch and keep the soil moist around the plants or trees. This can lead to shallow roots, fungus or other problems.
  • Loose soil is always better than a compacted soil under the mulch. Using products such as peat and fertilizer mixed into the soil to help loosen and feed the soil before mulching is always beneficial.