Managing and using garden leaves

LeavesLeaves are a valuable resource. They contain 50 to 80 percent of the nutrients a plant extracts from soil and air during its growing season. To keep our waterways healthy we need to stop erosion and intercept leaves and other organic matter from washing down our stormwater drains.

Here are 10 reasons why leaf management should be at the top of your to-do list.

  • Leaves protect shrubs and perennials from extreme temperature changes.
  • Its good exercise – raking, moving and mulching gets the heart rate up and fresh air into your lungs.
  • It’s a family affair, giving you the opportunity to spend quality time with your kids outside.
  • It’s an opportunity to demonstrate leadership. You’ll be surprised to see once you start managing your leaves, your neighbours will follow suit.
  • Leaves cleared from the streets and drains prevent injury, accidents and flooding.
  • Leaves that are mulched and managed on site save space in landfills.
  • Your garden plants, especially azaleas, camellias, and rhododendrons thrive with shredded organic leaf humus.
  • Leaves mowed into the lawn enhance clay or sandy soil, add natural fertilisers and introduce beneficial microorganisms to the soil.
  • Each year, tonnes of fallen leaves are blown or washed into our waterways releasing phosphorous and nitrogen and consuming oxygen as they decay, creating water quality problems in our lakes.
  • Managing your leaves is easy, ecological and the right thing to do.

Here are easy ways of managing and using leaves.

Mowing

A light covering of leaves can be mowed, either shredding the leaves onto the lawn where there is no danger of the leaves being washed off into the drain, or collecting them for composting or mulching. Mowing is the most effective way of managing small amounts of leaves. You can buy special mulching mowers as well if you have a lot to do.

Mulching

The purpose of mulch is to act as a barrier, keeping sunlight and some air away from the surface of the soil. This keeps the soil temperature more constant, conserves moisture and encourages soil microbial activity. Mulch also stabilises the soil and prevents erosion, improves soil structure and helps manage weed growth. Depending on the mulch you use, you are also adding organic matter to the soil.

Soil Improvement

Leaves may be collected and worked directly into the garden and flower bed soils. A 10 centimetre layer of leaves dug into a heavy clay soil will improve aeration and drainage. Autumn is the ideal time for using this method, giving sufficient time for the leaves to decompose before spring plantings. Adding a little fertiliser to the soil after working the leaves will speed up decomposition.

CompostingComposting

Compost is a dark, crumbly, earth-smelling form of organic matter that has gone through a natural decomposition process. Compost can be used for enriching the soil, loosening tight soils, enlivening potting mixes and as mulch. Any size garden has a use for compost. If you don’t want to do the composting yourself you can drop your leaves to a green waste recycling centre or pop them in your green waste bin (if you have one).

More information on composting is available on this website.

Piles or bins

Piles are easy, but you need the space. You will need some form of containment to stop the pile being spread by birds and the wind. Build your pile with leaves interspersed with enrichers like other compost, garden soil, nitrogen rich fertiliser or a compost activator.  Keep the pile moist but not wet. Turn occasionally if you are keen on getting your compost or, leave the pile alone and wait a little longer.

Bins can be basically any shape. It is more about what appeals personally and what is easier to use, like tumblers. The same layering process is needed for stationary bins, but in tumblers it is more about the mix of nitrogen and carbon rich ingredients (see composting for more details). Bins work faster due to the build up of heat and easier mixing.

Other useful resources

Actsmart – Mulch

Actsmart – The Importance of Soils