Fall is a beautiful time of year when all the leaves on the deciduous trees and shrubs change colours. These leaves play an important part in nature.

Throughout the summer trees are getting minerals from the soil and storing them in their leaves. These leaves are rich in minerals and when they fall to the ground and are left to decompose they slowly release their nutrients into the soil which in the end will help the tree grow.

It would be a shame to throw out these mineral rich leaves when they can do so much good.

In nature, or in areas where only trees, shrubs, perennials, are grown the leaves can be left on the ground, to slowly decompose, but if they are left to accumulate on the lawn they can cause a problem.

A thick layer of leaves will block the sun from the grass which is unhealthy for the grass. The leaves should be either raked up and placed somewhere else or have a lawnmower run over the lawn and fallen leaves and break the leaves down to smaller pieces which can then be left on the lawn. The leaves will slowly break down over the winter and provide nutrients for the soil.

If you chose to rake up the leaves, do not throw them out. They can be used as a mulch around trees and shrubs. Place a 5-8 cm pile around the trees and shrubs, but keep the leaves away from the trunk or stems as this can cause problems. The mulch will not only add nutrients to the soil, but it will also retain moisture in the soil, keep weeds down and help insulate against cold winter temperatures.

Fallen leaves are high in carbon material and are a good source of ‘brown’ for the compost. Don’t throw large piles of leaves on the compost as they take a long time to decompose. To break the leaves down faster, shred the leaves by using a shredder or a lawnmower. Then layer the leaves with ‘green’ material such as vegetable and flower plants that are being cleaned up from the yard, grass clippings, fruit and vegetable scraps, and weeds that are not noxious or ripe with seeds.

Shredded leaves can also be directly added to flowerbeds and vegetable gardens and then worked into the soil.

Another option that can be used with fall leaves is to make ‘leaf mold’. Leaf mold is a form of composting but only leaves are used and when it is broken down it forms a dark, brown crumbly material that is used as a soil conditioner. It improves soil structure, as well as help with moisture retention in the soil. Leaf mold can be made by placing leaves in a large pile or by putting the leaves in a large wire cage or bin. Add a little water to moisten the leaves and then let it sit. Leaf mold can also be made by using black garbage bags. The leaves are placed in the bag and the bag is loosely tied, and a few small holes are made in the bag. It is a slow process to make leaf mold, taking a year or more before it is ready to use. To quicken the process, shred the leaves first before placing them in the pile. The finished product can be used as a mulch or mixed in with the soil.

Whenever you use leaves to add to compost, leaf mold or mulch, make sure that the leaves are disease, and pest free. The last thing you want to do is spread any problems into healthy plants.  

-Jos

Jos van Hage owns and operates Art Knapp Home  and Garden Centres in Prince George

• Highway 16 West at Kimball Road
• Highway 97 North at Northwood Pulpmill Road