7 Tips for a Garden that Survives Heatwaves
Happy new year! Here’s a puzzle for you:
Q: What do these things have in common…
Carolina reapers.
The glob of wasabi you eat in one bite thinking it’s just a bit of avocado.
The vat of molten lava that Arnold Schwarzenegger gets lowered into at the end of Terminator 2.
Adam Brody.
Giant, roaring open flames.
A: They’re hot. But they’re not as hot as an Australian summer.
The sun is ROASTING, the garden is crisp. There are patches of lawn that are somehow still being missed by the reticulation system and they have turned the colour of lightly browned toast. The soil, full of worms and deliciously friable in September has turned miserably back to summer sand. A few of my precious plants - a Mexican currant that I nurtured for TWO BLOODY YEARS is probably (definitely) on the way out after Christmas in a parched pot, and I am starting to remember how I feel every single time mid-summer rolls around…
Cornflowers drying in the sun and setting seed
Gardening in Australia during the summertime is HARD. This is no one’s fault (although if you like, please feel free to blame the oil industry and whoever killed the electric car in the 70s). And for a few years I didn’t notice the pattern or realise what was happening. But every single February I would throw my arms up in despair, sweat running down my forehead, shoulders a delicate lobster sunburned pink, hose swinging ruthlessly around the garden like a beheaded snake; hitting everything and watering nothing. And I’d decide I wasn’t really a very good gardener (everything was dying!), that keeping plants alive was impossible (they grow so fast and wither even faster!) and that the best thing to do was pack it in and develop some other hobby that wasn’t so temperamental.
If this sounds at all familiar, don’t worry and certainly don’t give up gardening!! In an overheating planet, gardening is a wonderful way that each of us can help to sequester carbon from the atmosphere, provide insects, reptiles and birds with a place to call home, and create shady, green spaces that help cool our houses and streets.
We just need better tactics.
And after so many years of watching plants shrivel (which, I admit, I still find myself doing from time to time), I have developed some tactics of my own.
The mid-summer garden
1. Plant trees to create more gentle microclimates
Once established, trees are much more resilient to the heat than smaller plants and they can provide a shady understory where you can grow less sun-tolerant plants. In my garden, a curry tree provides much-needed shade for a pink hydrangea, silverbeet grows under the shade of a mulberry tree, and alstroemerias flower underneath the citrus trees. Whether your garden is big, small or in-between, trees are a fantastic idea, but a lot of people think that you can’t plant trees in a small garden. There’s a common misconception that small gardens require small plants. In fact, little plants can make a small garden feel cramped and crowded. Adding a tree in a well-chosen position can help provide some shade and add structure to even the smallest of gardens. If your garden is bigger, go the whole hog and plant yourself an orchard!
Alstroemerias growing in the shade of a Eureka Lemon tree
2. Prepare your soil with clay, manure, worm castings & lupin mulch
I aim to add clay, animal manure, compost, worm castings and lupin mulch to my garden 3-4 times a year, but this is most important during early spring because it helps to protect the soil throughout summer. It’s a bit like sunscreen for your garden. Without the lupin mulch and manure, the sun hits the soil, heating it up to the point where many of the micro-organisms in the soil die. The sun depletes the soil and over time impedes its ability to retain water and to harbour organic life. To some extent a little sun damage is inevitable in our hot Australian summers, but you can do your best to mitigate sun damage by boosting the quality of your soil throughout winter and spring.
Lupin mulch, added to the soil in early spring
Worms and worm castings from the worm farm
3. Focus on plants that thrive in hot, dry summers
It’s important to play to your strengths. Many a beginner gardener has been convinced they have brown thumbs because everything they initially plant dies. Nine times out of ten this isn't their fault. Garden centres will always aim to stock a wide variety of plants, which means that often a lot of the plants you’ll find there aren’t ideally suited to our climate (especially our very hot, very dry summers).
You can learn this the hard way through trial and error and a lot of dead plants (it took me three dead azaleas and several years to accept that my garden is just not a place to plant azaleas), or you can look at what thrives in gardens with similar climates. For us in Perth, this means either planting Australian natives (which have evolved to be perfectly suited to our climate), or plants that do well in the mediterranean climates of places like Spain and Italy. Better yet, ditch the idea that your garden has to be themed to any particular place and plant Australian natives AND mediterranean plants all happily in together!
Some of my favourite hardy mediterranean plants include: rosemary, citrus trees (water these well in the first few years; once established they’re very hardy), olive trees, bay trees, basil (likes rich soil and a good water every couple of days, but can tolerate harsh sun), fennel, zucchini, corn, chillies, pumpkins, squash, watermelons, geraniums, pelargoniums, sea lavender (statice) Wormwood, nasturtiums and Dogbane (Plectranthus Caninus Coleus).
A few other unexpected plants that seem to be doing well this year are: Tansy, Verbena Bonariensis, Salvia and Moonflower (Moonflower seems to be especially hardy, be careful with this one - it grows like a weed, but is very lovely - its large white flowers open at dusk and throw the most subtly sweet scent into the air for the moths and evening pollinators to find!)
Basil sharing a pot with a Meyer Lemon
Zucchinis growing in a patch of mint
4. Ditch small, unsealed terracotta pots
Unless you are prepared to hand water daily, retire your pretty little terracotta pots until autumn (or use them for cacti and other hardy succulents).
These pots are great in cooler months because their porous clay allows for water to evaporate out of the pot through the terracotta, meaning your plants are at less risk of getting waterlogged in the rain. In summer this can be a serious drawback as it means they dry out much faster than sealed pots (it seems I have to re-learn this particular lesson every year and am about to head back out to the garden to empty out at least ten little pretty pots now filled with sand and dead things…)
Spent artichoke blooms, Queen Anne’s Lace and fennel going to seed
5. Don’t give your plants any extra stress when its already hot
Do your best to minimise additional stress to the plants during summer - they’re already coping the best they can. Imagine if we were stuck out in the sun for hours on end in mid-January!
This means avoid transplanting or repotting plants while the weather is really hot, and don’t plant out anything in the middle of the day. If you do decide to put in new plants or if you absolutely HAVE to repot or transplant something, do it in the late afternoon and make sure the plants get a lot of water over the next few days to help them through the initial shock.
And always (but especially in mid-summer) fill any holes you dig with water before planting into them.
Verbena bonariensis
Long Thai chillies
6. Remember to look out for your other buddies in the garden
It’s not just the plants that are doing it tough - birds, insects and reptiles are struggling in the heat too. Provide plenty of access to water for all the different visitors to your garden.
For birds, a bird bath means a cool haven to bathe and drink. AND it is the happiest, loveliest thing to watch them ruffle their feathers and duck and dive into the water. Frogs and birds also love ponds, and nothing beats the calming sound of trickling water in a garden pond.
If you have the space I definitely recommend installing one! Bees, wasps and other insects also need water but can drown in a pond or bird bath. For them, it’s best to get a shallow tray and fill it with pebbles, marbles or glass beads, then top it up with water. The pebbles give them a landing spot so they can access the water without drowning.
The garden pond with a pebble beach (bottom left corner) to provide a safe place for bees, wasps and other insects to land
7. Don’t beat yourself up!
Last, but maybe most importantly: don’t give yourself a hard time if your garden is struggling over summer. It’s a legitimately tough season to get through if you’re a plant AND if you’re a gardener!
Remember that different environments bring different challenges to every gardener - in the UK they have to deal with frosty, muddy winters, skeletal trees and flowerless fields. In Australia we have mild winters but instead face arid, dry summers, blistering heat and sandy soils.
Wherever you live, it’s really hard to have a beautiful garden all year round and every moment of the day. But perfection is a myth and it’s the act of gardening that is important, so get back out there and keep getting your hands dirty!
No matter what the next few months of ridiculous heat brings us, summer will eventually pass and autumn will bring thick, trembling grey clouds, lightning over the ocean, and rain that will feed your parched soil, breathing life back into the landscape once more. And, as with every new day and every new year and every new season, we’ll all be given the wonderful opportunity to begin again.
Pumpkin vines rambling through flowering pink Pelargoniums and a Cistus bush
A climbing rose, fennel flowers and dried cornflowers