What is the correct amount of mulch to use?

When using natural mulches, such as shredded bark and wood chip materials, the recommended thickness for use around trees, shrubs and evergreens is 3 inches. Remember to periodically add more mulch to planting areas as it decomposes, but be careful not to exceed the 3-inch thickness at any time.

Mulching around perennials is also recommended to help conserve moisture and to help control weeds. Apply 1 to 2 inches of mulch around plants, however be sure to keep the mulch at least 2 inches away from plants’ stems to avoid possible damage.

Is there really any difference between wood chips and shredded bark? Should I use chips or shredded bark?

Generally speaking, wood chips are made from the actual interior wood of a tree, while bark chips are composed of the outer portion, or bark of various tree species like cedar, pine, or eucalyptus. Shredded types of bark may be all bark, or contain some wood due to the types of raw materials used to produce the particular product.

There are so many different types of mulches available…varying colors, textures, sizes of chunk, etc., that selecting a type of mulch becomes more of a personal preference than anything. All mulches will have beneficial properties that include moisture conservation, weed suppression, and soil temperature moderation.

When selecting a type of mulch to use, more consideration should be given to whether the material is in chip or chunk form versus a shredded type. Chunks may have a tendency to move around more than shredded types which tend to lock in place once they have been watered down. It may be advisable to use shredded mulch types in windy areas or those receiving high amounts of foot traffic.

I love gardening in the spring, but I dread having to dig planting holes because my “soil” is really hard clay.  Can this clay actually be transformed into good soil or should I just dig it all out and bring in fresh topsoil?

Clay soils that have not been abused by construction traffic, compaction, or improper tillage can actually be great soils in which to grow plants. Unfortunately, most homeowners are cursed with clay subsoils (where the topsoil was removed for development) which usually become hard, compacted nightmares.

One solution to this problem is replacing clay with topsoil. This can be effective in small or difficult areas, but can prove to be costly and problematic since you have to find a home for all the clay you just dug out. This rock-hard clay can become a pretty good growing soil if you invest some digging work, soil building ingredients, and time. First, you’ll need to break up the clay to begin the process. Turn over the soil with a digging spade or fork and break apart the chunks as much as possible. Soil that is too dry will be difficult to penetrate and break up, while wet soil will be easy to penetrate, but difficult to break apart cleanly. You may find it necessary to wait until soil moisture conditions have improved to make this task easier. Once the area has been turned, rototill the area until you have reduced the largest chunks to 1 inch in size.

Spread 2 to 3 inches of organic matter such as sphagnum peat moss or compost into the area. Rototill the area again until the material has been thoroughly incorporated. Then add another 2 to 3 inches of the same material over the same area and rototill again. The addition of organic matter will help transform your clay into a workable soil over time, but don’t expect a miracle overnight. It may take a few seasons of further adding organic matter and spot turning the soil where plants are not present. Organic mulches will also help build the soil as they decompose when the earthworms do their job by moving these materials through the soil. The long-term success of this soil building project revolves around the continual addition of organic matter, which can be thought of as the fuel in the tank of a car. If you stop adding fuel to the tank (soil), it will eventually run dry and cause the car to stop running.