As summer crops and blooms wind down and cosiness calls, it’s time to prepare our outdoor spaces for the cooler months. Getting your garden ready for winter doesn’t have to mean costly trips to the garden centre and can instead be approached with resourcefulness and a focus on “closed systems” that minimise waste and encourage biodiversity.
Save those seeds
Belinda Thackeray, horticulturist and manager of Sydney City Farm, says now is a great time to turn plants on their last legs into a resource for the warmer months. “We try to save seeds off anything that we’ve got … it’s a really important part of the cycle.”
Thackeray explains there’s two common ways to make the most of annuals as their productive season ends. Firstly there’s wet production, “for things like your tomatoes, your cucumbers”. This method involves gathering the seeds of fleshy produce and soaking them in water. This process loosens the “jelly sack” that covers the seeds. After a couple of days that sack should slip off, along with any pathogens it might harbour. You’re left with a clean seed, ready to be dried and planted later in the year.
The second method is useful for herbs and greens. As they go to seed, Thackeray suggests lopping off larger stems that are producing flowers or seed pods. “Then you put them upside down in a brown paper bag, and leave them to dry. As they do, all the little seeds will drop into the bottom of the bag for you to plant in the next warm season.”
For ornamental annuals, seed saving can be as simple as giving the plant a good shake before ripping it out.
Soil solutions
Once you’ve collected seeds, the next thing to do is cut back perennials and clear out annuals. Thea Kerr, nursery manager at Ceres in Melbourne, says we need to be mindful of what we do with that foliage. “Some people opt for a chop and drop method, but that can be problematic with things like cucumbers which might have incurred a bit of fungal disease as it starts to get cooler.” Thackeray meanwhile cautions against letting any fruits or seeds get into a “cool compost” unless you’re hoping for a “sea of tomatoes or melons” when that compost gets scattered. “A nice hot compost” she says makes the seeds unviable and less of an issue.
At this late stage of autumn, both Thackeray and Kerr suggest a “green manure” crop as an effective way to nourish the soil in areas you won’t be planting out during winter.
Green manure seed mixes, which usually contain a mix of cereals and legumes, can be bought online and in most nurseries. The seeds are sown into cleared garden beds and then dug back into the soil right before they flower. This process enriches the soil and can even kill off harmful pathogens. From planting to decomposition, the process usually takes about 14 weeks, so doing this in May would see most gardens through until it’s time to get things ready for spring.
If you do plan on planting, a good homemade compost or fertiliser and mulching is essential. As the temperatures cool, mulch is particularly important, says Thackeray: “Putting down mulch is like putting down a blanket, it keeps the soil nice and warm and helps the plants to get going.”
What to plant?
When it comes to winter crops, Thackeray says “things like broccoli, broccolini, kale, lots of varieties of peas, radishes, beetroots, carrots, coriander” are on her list. But Kerr reminds us that – after climate suitability – the most important consideration when planting crops is what you actually enjoy eating.
Thackeray also suggests making the most of pruning: “As you give your perennials their autumn haircut, you can then also take those little pieces and then grow some new plants.”
With “shrubby things” such as lavender, grevilleas and rosemary, Thackeray recommends “chopping off a piece of plant about 10 to 15cm long, where the top of it is floppy but it has a bit of hard stem. You leave the top one-third of the leaves and strip off all of the others.” Next, you’ll make a nice little hole with a pencil or chopstick and slide half that stem into the ground. “Then you just need to keep it moist and it will grow roots. It works a treat at the moment.”
Keep it moving
Thackeray says that autumn can be the perfect time to break up rhizomes and tubers and redistribute them before the cold sets in. “Because they’ve finished their major growth phase it’s a really good time to move them because they’ll have some time to establish themselves in their new home before they go dormant for winter.” Think cannas, lilies, dahlias and their cousins.
Bring in the bugs
Getting some pollinators in your garden over the winter is another good idea. “Bringing in insects helps with pollinating the plants, but also helps with pest and disease management,” Thackeray says, recommending the classics such as calendulas, violas, pansies and poppies. Kerr also says autumn is an ideal time to get some flowering natives in, which will increase biodiversity and keep your local ecosystems healthy for years to come with very little maintenance.
