Hold the fertilising, winter’s here, says gardening writer JACKIE WARBURTON.

WITH winter just around the corner, there should not be any fertilising from here to spring as plants can’t take up nutrients from the soil if the temperature is under 10 degrees and it is wasted. 

Fish-emulsion products, which are a soil conditioner not a fertiliser, can still be applied.

The ground will not really warm up until October, when the growing season starts again, so now’s the time to work on soils and get the microbes and worms working, which will help the spring garden to a good start. I believe the garden is a busier place in winter than in the warmer months with so much to do. 

TREE dahlia (Dahlia imperialis) is a super-fast-growing perennial and can grow up to five metres tall in one season. 

Bees are highly attracted to tree dahlias. Once they’ve flowered, they can be chopped down into segments about 60 centimetres long with at least two nodes. Bury and cover them with soil and mulch. In the spring time there should be new shoots appearing from the nodes and there’s a new plant for the garden. 

NOW’S a good time to spray all fruit trees to prevent peach leaf curl in spring on peach and nectarine trees. A fungicide is required, and I use copper oxychloride and spray under the leaves. I also pick up and remove any fallen leaves. Most fungal diseases can’t be seen with the naked eye but show signs of being there on leaves. 

Copper can also be sprayed on apples, pears and plums for shot hole diseases that are seen in summer. Repeat spraying in winter and spring, spraying when the weather is not too windy or there is rain about. Be mindful not to spray near water bowls or ponds as copper is harmful to aquatic life. 

TURNIPS and broad beans can still be put in the garden along with kale, leaks and lettuces. They might need a little night protection with a cloche and removed in the day. 

GROWING veggies by hydroponics can be done in Canberra outdoors and, in my case, it was a successful project. 

My yield of tomatoes was extended until May because the water had a heater and reticulated warm water throughout the system. This allowed me to have tomatoes growing in the same spot without crop rotation being an issue; broccoli in winter and tomatoes in summer. 

The system I used for these larger vegetables was a “bucket and drip” irrigation system and different to the “ebb and flow” or flood or drain system that is used for smaller herbs and greens. 

The “ebb and flow” is a simple system that involves the periodic flooding and draining of nutrient solutions past the roots. This method of hydroponics can increase yield and is great for leafy greens that like to be picked often. 

For growing on a balcony or small space, the main advantage of hydroponics is that there’s no heavy soil to deal with and most of the products are lightweight and easy to use. 

For anyone renting, it is a terrific removable system to take when moving. There’s a lot of information online and there are stores in Canberra with helpful staff to answer any questions. 

jackwar@home.netspeed.com.au