December always arrives with that sudden rush of summer energy. One minute the garden feels like it is stretching after winter, and the next it is in full stride, pushing out new growth, ripening fruit and filling every corner with colour. It is the month where the edible garden really shows what it is made of and the rewards of earlier planting begin to shine through. I always think of December as the garden’s version of deep breath and long exhale. Everything grows fast, everything needs something, and everything feels alive.
What to Plant
With the true warmth settling in, the soil is finally warm enough to plant all those heat lovers that have been waiting patiently. December is the ideal time to get capsicums, chillies, eggplants, zucchinis, cucumbers, pumpkins, okra, celery, corn and advanced tomatoes into the ground. They thrive in the long days and warm nights and as long as they have steady moisture and a bit of nutrition, they will repay you with an abundant summer harvest. Lettuce, spring onions and kale can still go in this month too, but they appreciate a little afternoon shade to keep them crisp and stop them bolting.
What to Sow
Seed sowing continues beautifully in December. Beans, carrots, parsnip, radish, silverbeet and turnip all germinate well in the warmth. Parsnips in particular are worth the patience. They are always best grown from fresh seed direct into well prepared soil. I like to start them in a light seed raising mix on the surface and let the roots push down into the garden. Once the seedlings appear, thinning them gives the roots space to swell. Parsnips do their best work when left undisturbed, so plant them where they will stay until harvest.
Brassicas can be a bit of a game this month, because the heat encourages them to bolt. If you are keen, sow them into a spot that gets morning sun and afternoon shade as the reduced heat helps keep them steady. Keep a close eye on cabbage white butterflies. They absolutely adore tender brassica seedlings at this time of year. Food grade diatomaceous earth or a light application of Eco Oil is all you need to give the seedlings a fighting chance. Both options remain gentle on your garden ecosystem and fit perfectly with the organic values we hold close at Harmony.
The ornamental garden is equally lively. December is the time when roses, fuchsias, geraniums and summer annuals hit their stride. A good feed with a balanced, quality fertiliser and regular watering keeps them flowering right through the festive season. Sweetcorn and tomatoes respond well to a layer of mulch now, helping hold moisture in the soil and keeping the fruit clean as it forms. Hanging baskets, pots and garden beds all benefit from wetting agents at this time of year as the heat sets in.
As the garden grows, it is a perfect time to tidy, top up mulch and encourage new summer blooms. Roses respond beautifully to deadheading and deep watering. Finished shrubs can be trimmed to encourage new summer growth that sets up next year’s flowers. Even tomatoes benefit from a bit of tidying as removing the lower leaves helps improve airflow and keeps soil borne disease at bay.
Shot Hole Disease continues to pop up around Tasmania, and it is often mistaken for insect damage. The small holes in the leaves come from purple or reddish spots that form earlier in the season. These spots eventually drop out, leaving the distinctive holes. Shot Hole is fungal and thrives when leaves stay wet, so avoiding overhead watering makes a significant difference. Treatment is always most effective when trees are dormant, long before buds begin to swell.
December always feels like a month filled with potential. With warm days ahead, fruit forming, bees working overtime and the soil finally holding heat, it is a time when planting, tending and observing all come together. If you ever need a hand deciding what to plant, where to plant it or how to keep something thriving, pop into Harmony. There is always someone here ready to help you grow a garden you love.
See you soon!