Secrets of growing onions in Canberra

Onions are shallow rooted and struggle to compete with weeds. As such, do not embark on a planting program if you think that you will be too busy to keep the garden bed well weeded over the coming months.

Some garden experts will tell you onions are one of the easiest vegetables to grow in the temperate regions of Australia. However, if you want to be a fully fledged home gardener and grow your vegetables from seed, then the first challenge is to get your seeds to germinate.

Part of the answer lies in the timing. The early maturing white and red onion varieties should really be sown from mid-April to mid-May. Seeds for long-keeping Brown and Creamgold varieties should be sown in May or early June.

Creamgold is a large globe-shaped onion with light-brown skin and creamy white coloured flesh. It is rated as the best-keeping onion. I have planted out both Creamgold and early Creamgold seeds this autumn. This family of onions requires longer daylight hours in spring to trigger bulb formation, so they will not commence bulbing until late October and will not reach maturity until January.

Australian Brown and Riverside are two other good, long-keeping varieties. Red Shine is a lovely red, high-yielding onion suited to the colder, temperate regions of Australia.

I have preferred to sow onion seed into propagating trays. This allows me to control the germination micro environment better, than if I were to plant the seeds directly into the garden bed. You are aiming to have well-developed seedlings to transplant in August.

However, have a go at direct drill planting into your garden bed. Sow only to five millimetres and space out well, otherwise you will need to thin out or transplant every second seedling. Do make sure your soil has been enriched with lots of really good compost. The shallow root systems do need to be able to easily access nutrients.

You can plant about 60 onion plants in one square metre of garden. Allow around 70 millimetres between seedling.

Onions take between six and eight months to grow through to maturity. Harvest only when the tops are well dry so that the onions are well cured. Dig out with a garden fork so you avoid damaging any of the bulbs and so you can gently prise them out without doing any damage.

To prepare your onions for storage, place the harvested bulbs in a dry, sunny pathway or somewhere protected from overnight visitors. They do need to be completely dry before you store them in an open-weaved bag.

Apple, onion and potato gratin

3 medium granny smith or mutzu apples

Juice of 1 lemon

1 tbsp brown sugar

ground cinnamon

500g onion

500g potato

cayenne pepper

pinch of salt

4 tbsp fresh cream

4 tbsp butter

½ cup grated cheese

1 cup breadcrumbs

Peel and core apples then slice them quite thickly. Preheat the oven to 200C. Grease a medium-sized casserole dish.

Mix the sliced apple with lemon juice, brown sugar and sprinkle lightly with the cinnamon. Peel then finely slice both the onions and potatoes, then mix them together. Layer the onion and then the potato in the casserole dish, adding a touch of salt, and lightly sprinkle with cayenne pepper. Fill to the top of the casserole dish finishing with a layer of apple. Pour the cream over the gratin and then place dollops of butter on top.

Bake for about 45 minutes. Then sprinkle the grated cheese and breadcrumbs on top, and add more dollops of butter. Bake for a further 15 minutes.

This week in the garden

■ Keep cleaning up your summer garden beds and look to plant out a green manure crop or a nitrogen fixing crop of peas or broad beans to naturally build up the soil quality.

■ Keep up an active weeding program of your newly planted crops. Cut down all ageing asparagus foliage.

■ If you have planted out leeks in late summer, earth up the soil around the stems to keep them well blanched.

■ Keep raking up all fallen leaves and add them to the compost, along with the green grass and weeds.

■ Begin pruning your peach and nectarine trees.

>> Owen Pidgeon runs the Loriendale Organic Orchard near Hall.