It’s Time to Mulch and Shade

Spinach and chives growing in a half wine barrel with drip watering pipe and mulch also visible.

Watch out South Australians, there’s a heat wave coming next week! The forecast for Adelaide is for 40°C on Wednesday so that means we need to spend some of the weekend getting our homes and gardens ready for it.

For me, it’s time to pull out the shade cloth screens that I’ve cut to size for each of our windows and have them ready to go on the outside of the windows during the heat of the day. They’re just hooked onto a couple of nails or cup hooks and I tend to unhook one side of it when the sun goes down or the air is cool enough, to let the natural light back into the house. It makes a world of difference to the indoor temperature, especially when combined with the best quality curtains or blinds you can afford on the inside of the house.

Last year I invested in some block-out curtain fabric from Spotlight and I’ve replaced several sets of curtains that didn’t have that block-out layer on the reverse side. In combination with the outside shades it keeps the house much cooler. With thick walls for good thermal mass and ceiling fans, plus keeping the external doors, bathroom, laundry and other utility doors closed, we can be quite comfortable for many days without needing to use the air conditioner. (We generally only use the air con when it’s over 35°C for five days or more.)

Meanwhile in the garden, I need to get out there and get some compost on some of my vegies (I just add it on top and let the worms work it in for me), and give the plants a good deep water over the weekend to get them as fit and strong as possible before the hot weather hits. If I’ve got time, I’ll give them a bit of liquid manure too with worm ‘juice’ and seaweed solution.

Then the mulch on top is critical to keep as much moisture in the soil as possible. I use whatever is locally grown – generally straw of some sort. On top of that I chuck on some woody trimmings. This weekend it will be broad bean plants as they’ve finished fruiting and they’re thick enough to deter the blackbirds from scratching through the mulch and flicking it all off the plants!! Soon the nasturtiums will be finished and they work really well for that too. Sometimes I just use gum tree twigs but they’re less beneficial to the vegies as they break down.

The lawn will get a water this weekend too and the moisture in the soil will create a cooling effect around the house. In tandem with shady trees and shrubs, this can reduce the temperature around your home by at least 5-8°C. That’s a big difference on a hot day. Urban heat mapping shows a huge difference between a home with trees, grass, and shrubs and one with paved, gravel and hard surfaces with no shade. Plant transpiration cools the air. It’s too late to be planting new trees and shrubs unless you’re prepared to water them at least once a week through to Autumn, but it is a good time to observe where your home’s hot spots are and to research what you could plant in winter to make it better next year.

Another job is to fill up the bird baths. We have three in different parts of the garden. One little bird bath on a pedestal for the smaller birds, one larger one in a more open area for the large birds, and one at ground level for the mammals and lizards, though the New Holland Honeyeaters love it too. We’re always coming outside to find the water sprayed all around and the cute little black, white, and yellow birds preening themselves on nearby branches after a good bath. They’re so adorable – and great plant-pest eradicators!

The other birds that need a little extra care during a heat wave are our chickens. I can’t prep much for that but I can at least make sure I’ve got some extra water tubs out and clean, ready to fill when the heat hits. Some chooks won’t go to their usual drinking water during extreme heat so you need to give them a few options, making sure it’s all in the shade so the water doesn’t heat up too much. Aside from that, I’ll wet down the ground in their yard in the shadiest spaces to give them some cooler spots to sit in and to cool the air.

If you compost food scraps with a worm farm you really need to set up something to create air conditioning for them or they can all die from heat stress. This happened some years ago in South Australia when all the commercial breeders lost all of their worms. We lost nearly all of ours too but were lucky to have a few make it. Your worm farm should be in the coolest, shadiest place you can at all times, but during a heat wave they need some extra special care.

In the past we’ve used old towels or hessian, soaking wet, draped over the worm farm (which is elevated), with one end dangling in a tub of water. During the day we’d go out once or twice and re-wet the towel or hessian. We’ve got a better system rigged up now in which we still have the towels or hessian wet and draped over the worm farm, but then on top of that we have a water container with a tap (from our camping kit), with the tap opened enough to have a slow drip of water coming out and keeping the towel or hessian wet all day. We had to experiment a bit to get the flow rate right, but it’s worked really well and creates all-day air conditioning to give the worms the best chance of surviving to keep our composting going in the long term.

As for the chickens and worms, extreme heat can kill humans too! Drink lots of water and other cool drinks. Stay in the shade, especially in the heat of the day. Heat exhaustion is dangerous and heat stroke can be fatal, so check out the signs, tips and treatments on the Red Cross website.

Many plants and animals have extremely narrow temperature ranges in which they can thrive – a few degrees can make the difference between thriving and suffering, life and death. Get prepared now so you, your pets, our native animals, and your garden come out of it as well as possible.

© Palitja Moore, text and image, 2019

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