Late summer to early autumn is probably my favourite season; the nights are a little cooler and more comfortable, the days are typically warm and sunny with only sporadic rainfall, the townies have headed back to work in the city leaving the beaches and cafés for us locals to enjoy, the water is still warm and, most importantly for me, my subtropical garden is looking its best.
It seems like everything in my garden is in flower. Brugmansia, frangipani and ornamental ginger load the evening air with their luscious scents; lotus and tropical water lily hold their exquisite blooms above their water bowls; drifts of bromeliads, canna and heliconia provide drama with their vibrant colour; potted bougainvillea and summer flowering bulbs provide stunning accents.
Before I wax too lyrical though, this is also a season to refocus on work in the garden after the summer holidays. Apply a liberal dose of a fast-acting fertiliser to most plants now to keep them actively growing until the weather cools. This is best done now, as applying fertiliser too close to winter may produce weaker, sappy growth that is prone to frost damage and disease. The exception to this rule are deciduous fruit trees, these are best fertilised in spring and early summer.
Populations of mites, passion vine hopper, thrips, aphids, psyllid and mealy bug will all be flourishing in this balmy climate. Spray with neem oil and insecticidal soap for low-toxicity control, but if there is a population explosion, then you may need something a little stronger to knock them back. There are several effective insecticides available to home gardeners, but make sure you follow label instructions to the letter. Suit up and mask up to keep yourself safe, and above all, avoid spraying when bees are active.
This is also a good time to be propagating plants, when plant energy starts transferring from rampant top growth to storing in stems and roots for the coming winter. Strawberry and raspberry runners can be cut off, dug up and potted to plant out later. Likewise, bromeliads, cannas and many other plants oblige us by producing offsets which can easily be removed and transplanted. Softwood or semi-hardwood cuttings (cuttings that have soft top growth, but also a portion of the woodier growth below) can be taken from many plants at this time of year.
I like to use the old-fashioned method of placing cuttings in a clear glass bottle in a well-lit area, replacing the water every couple of weeks or so to keep it fresh. The kitchen bench is usually ideal as it is easier to keep an eye on them. Eventually, little white nodules of callus will appear on the stems, followed a few weeks later by little roots. The cutting can then be potted up. Some cuttings won’t make it, expiring before they take root, so it’s always a good idea to take a few more than you need. You can always give away any excess.
Like everything in gardening, if you’re not sure you can do this, just give it a go. Very easy plants to start with are tomatoes (make sure they are disease and insect-free first) and coleus. These almost always work. Then move on to harder to grow root plants, such as gardenia and hibiscus. In no time, you’ll be growing your garden for free!