Keep your garden thriving in the heat. Expert tips on summer mulching, pruning, and seaweed spray for a lush, resilient yard.
It is hot. You are hot. The neighbour’s dog is hot. will delight in the heat. The bushfire summer of 2019 gave us our first crop of dates: I’d assumed our climate was too cold for dates, though the foliage tolerates frosts. The bananas did wonderfully, as did the Kei apples, which are not really an apple, but a type of desert plum from the dryer parts of southern Africa. The skins are tough, but inside the flesh is sweet and luscious, even as the roses wilt.
Unless your garden is mostly sun-loving, it will need some help to look its best, or even just survive. The obvious solution is water. Water yourself, and the kids, as well as the garden, preferably at night and in mozzie-proof long sleeves and ankle protection. Yes, the clothes will get wet, but the wet clothes will cool you, as you water the roses. Watering at night means the soil stays damp longer.
Mulching helps keep moisture in and increases water penetration as worms and microflora incorporate the mulch into the soil, as well staying damper for longer. But use summer mulch — light, airy materials such as sugar cane slash or last year’s old corn stalks that will let the moisture from short rainfalls penetrate.
On the other hand, if you are on a steep slope or expect deluges, a dense mulch, such as decayed leaves or even compacted dry lawn clippings, will help stop soil washing away in heavy rain. Use your judgement and only use a dense mulch if you are sure it’s needed. Don’t use lawn clippings until they have dried out, as moist green ones can heat up. Never use lawn clippings for mulch in a drought unless mixed with autumn leaves and weeds.
The next slightly drastic step is pruning back your shrubs. This means they transpire less moisture on hot days. You may not get blooms for a month or two, but a mid-summer pruning means a magnificent blooming autumn. The exception is any shrub that only blooms once a year — prune it just after flowering, or you may not get any display until next year.
Almost any plant that wilts can be summer pruned, including citrus. All citrus are shallow rooted and easily die in the heat unless watered. A good pruning can help. Don’t assume native shrubs don’t need watering. Most natives have a sensible response when it’s too hot and dry: they flower, produced seed, then die, so their seedlings germinate when the weather is kinder. Prune them, water and mulch.
Just like small kids and the elderly can lose their appetites when it’s hot, plants can stop taking in enough tucker from their roots, especially if the soil is often dry. Give them a weekly dose of foliar seaweed spray, spraying under and over the leaves — preferably not just before a mid-summer thunderstorm. The seaweed spray will feed the plants through the leaves, as well as possibly thickening the outside of