Compost before the heat hits

This hardy wallflower blooms for months from mid-winter to late spring and is a perfect companion for spring snowflakes (Leucojum) and prostrate, limey gold Euphorbia myrsinites.

There are several of these shrubby wallflowers, all sweet smelling, drought hardy and dead easy to keep going from November cuttings.

Look for buff and mauve Erysimum bi-colour, and Siberian wallflowers in vibrant shades of orange, red and egg yolk yellow.

Having stuck my nose into the wallflowers and picked a few for my desk, I make a list of things to do in September.

We're coming into the garden's period of maximum growth and it's important that plants are well fed so they can take advantage.

Compost is the best fertiliser: check your heaps and dig out everything ripe and rotted to spread over bare earth (which you have first conscientiously weeded).

Do it now, before the weather turns hot overnight.

Push up the remaining, unrotted material, dig in some manure, then water it well and cover with a sprinkle of soil to mature over summer.

I never have enough compost, so the rest of the garden has a dose of either blood and bone or pelleted chook manure fertiliser, not forgetting my roses and other plants like peonies that are known as 'heavy feeders'.

Raking is another urgent task. Birds had a lovely time during winter scratching beneath last summer's mulch and spreading it over adjacent paths and lawn.

I rake it back onto the beds, together with quantities of desiccated autumn leaves, hoping rain will soon break it all down into lovely much-needed humus.

Early September is the last chance for planting but apart from dahlia tubers and autumn flowering bulbs, beware in a drought of planting in spring as new plants will need a heap of water over summer.

It's easier to keep a group of pots damp than a large expanse of garden bed, so if in doubt, re-pot plants into bigger pots.

Use top-quality potting mix or compost if you can spare it, add water crystals and top off with a layer of mulch - gravel is excellent.

With any luck, it will rain before next autumn and we can plant then.

I usually divide ornamental grasses in September but this year I'm cutting them to ground level and letting them be, rather than risking sudden death.

I once lost a treasured Blue Oat Grass (Helictotrichon sempervirens) by splitting it in a dry spring and have regretted it ever since.

September is magnolia month. Magnolia (syn. Michelia) doltsopa is a small tree from the eastern Himalayas, with creamy, heavily fragrant flowers and long (5-15 centimetres), glossy, evergreen leaves.

Wildwood Garden, 29 Powells Road, Bilpin is open Friday to Monday through September and October, 10am-4pm, entry $10, concession $8.

Expect a glorious woodland garden, specialist nursery and café.