Autumn Tasks for Winter Gardens

Green Lifestyle's guide to getting the most out of your garden this winter.

Tip 1: Cover your compost with a weed mat to protect it from weed growth and excess rain.

Edible green manure plants, such as broad beans, can be left to flower and go to seed before digging into the soil - then you'll have an early crop of beans in sprint as well.

Remove frost sensitive plants inside or closer to the house, or put them higher off the ground where the frost won't settle on them.

Keep slimy critters away from plants by saving eggshells from the kitchen and crushing them around the base of plants - the pests don't like rawling over sharp edges.

Credit: istock

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If you’ve just had a bumper crop of summer veg, it’s no time to rest on your laurels. Get out the gardening gloves, because autumn is one of the busiest times in the garden.

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April and May are great months to get in the garden in Australia. Apart from being the major harvest period of the year, it’s when good organisation informs the success of the following growing season. In between harvesting pumpkins and tomatoes at this time of year (or wishing that you were!), here are the main tasks to keep you busy in the garden right now.

Plant green manures
Once you’ve cleared a garden bed, you could choose to plant a winter crop or leave it ‘fallow’ over winter. However, if you choose to leave it empty, nature will soon fill it with weeds. The smarter choice is to plant a green manure crop over winter. This is a high-nitrogen crop – usually a legume – that aids soil health and fixes nitrogen.

Once the plant is at the point of flowering, it’s time to dig it back into the soil, allowing it to rot down in time for planting a spring crop. In nematode-susceptible areas (warmer climes), a green manure of mustard can help cleanse the soil as well as adding nutrient in the form of organic material.

There are green manure packs available commercially; you can talk to your local rural supplier for advice on what suits your climate and isn’t likely to become a garden pest. I’ve found that broad beans work well, as they create a dense weed-suppressing canopy, are nitrogen fixers, and, most importantly, the birds don’t eat the seed.

Create compost
Start a compost heap now and you’ll be rewarded with beautifully rotted compost by springtime – ready for powering your plants. It’s nutrient recycling at its very best.

First, choose a sunny area of the garden that will remain in the sun for about half of the day during winter, and is preferably in part-shade in summer. There’s no need to place it far away from areas you regularly use, as a good compost pile should smell sweet.

Healthy compost should have a lot of ‘dry’ carbon material layered with a little nitrogen, or ‘wet’ material, with a carbon-to-nitrogen ratio of 25:1. If there’s too much carbon, decomposition slows down, and if there’s too much nitrogen you’ll end up with a stinky mess. While small batches are possible using a rotating drum-style compost bin, generally a critical mass is required for bacteria to work. Make your pile large, and add more material as you go to ensure the bacteria have enough to ‘eat’.

To activate the compost heap, you’ll need a few layers of material that are very nitrogen-rich. If you’re lucky enough to have chickens, scrape up the bottom of the chook pen. Green plants such as old pea and bean plants, or even fresh kitchen waste, work well too.

After harvesting your summer vegies, you’ll have loads of carbon-rich dry material available in the form of spent plants – corn stalks and leaves are perfect. You can also use straw, cardboard, paper, leaves from deciduous trees and any dried plants, but be careful not to add the seed heads of plants you don’t want to see again.

The regular application of air helps too. This means turning over the pile, or inserting a sharp implement deep into the pile to provide pockets of air to aid decomposition.

Check your soil pH
All too often, garden disasters are caused by incorrect soil pH. Australian soils are often acidic, and while strawberries, raspberries, blueberries and tomatoes are happiest in an acid soil, there are many other plants that will turn up their toes. Trace elements such as nitrogen, phosphorus and molybdenum are unavailable to plants in an acidic environment, and manganese, iron, copper and zinc are ‘tied up’ in highly alkaline soils. Aiming for a soil pH of 6–7 will ensure that most plants can source what they need.

Autumn is a good time to get on top of soil pH, as it can take time to adjust pH levels. If the soil is too acidic, agricultural lime or dolomite can be added. If your soil is too alkaline, composts and some manures (not chicken) can help, as can an iron chelate or an organic sulphur compound.