AS we fill our compost heaps with autumn leaves, think worms.

Compost heaps heat up with decomposing green waste and then gradually cool down.

During the cooling period our common-garden earth worm moves in to the heap. These should not be confused with worms used in worm farms. Reading the UK “Country Life” magazine, the following comment is applicable at this time: “Our special friend in gardens, the earth worm, Lumbricus terrestris and allies should be given a round of applause.” Charles Darwin considered earth worms important enough to occupy his attention for 40 years. His book “The Formation of Vegetable Mould through the Action of Worms” (1881) has a more compelling narrative than the subject might suggest, underpinning all modern knowledge on soil fertility and structure.

 

DARWIN likened the work of earthworms to that of “a gardener who prepares fine soil for his choicest plants”. Since then, intelligent gardeners recognise worms as the creators of the best-quality soil, especially worm casts.

In a year, a healthy population can digest 100 tonnes of soil per hectare. Contrary to popular belief, worms accidentally cut in half do not regenerate into two separate worms. If you cannot find plenty of worms to improve the soil in your garden, your plants will have a job growing.

 

NOT all the autumn leaves I collect go into the compost bins. Many folk curse autumn leaves, but leaves are one of the most valuable sources of organic garden material. I get annoyed when I see people raking them into the street gutters, clogging storm-water drains etcetera.

In our street, I use the mower as a vacuum cleaner to collect leaves in the gutters, shredding them at the same time.

Shredding leaves such as eucalyptus and oak with the mower will hasten the decomposition process. One half of the leaves I collect go on to the compost heap and the other half is spread directly onto the garden.

You do not have to dig them in as worms just love rotting leaves and will quickly work them into the soil. Incidentally, oak leaves have the highest content of nitrogen of any leaf.

 

WITH trees changing into their autumn mantle, it is time to think about deciduous trees to plant for summer shade.

However, before even thinking about what variety to plant, it is vitally important to consider underground services. I cannot emphasise this enough. When I visit gardens, owners often have no idea where underground gas, electric, sewer, storm water, phone lines or even the location of the water meter are.

Usually, the spread of the root zone is equivalent to the leaf spread of the tree. Root damage can result if you plant a tree too close to paved areas or driveways.

 

FROST will occupy gardeners’ minds over the next few months. Looking back over weather bureau statistics is interesting. The earliest recorded frost here was in March 1940. The earliest last frost was recorded on October 1 and the latest frost was recorded on January 2, 1956. The median date for the first frost is April 9 and the last frost is November 16. One important point, if shrubs are burnt with frost, do not cut off the damaged leaves. These will protect softer leaves under the damaged ones. Wait until the last frosts before trimming damaged leaves. This is equally applicable to such perennials as bedding begonias.

During crispy autumn days:

• Plant out biennials that grow this year and flower the following year. These include Sweet Williams and Digitalis or foxgloves.
• Add a few handfuls of blood and bone to every few barrow loads of leaves to accelerate decomposition.
• Do not prune deciduous flowering trees at this time or you will cut off flower buds.
• Complete planting spring bulbs including tulips.
• Plant Clematis nepaulensis, a winter-flowering clematis.