Heatwaves are a regular occurrence during the Aussie summer. Paved areas, steel fences and brick walls can amplify the heat, making your garden microclimate extremely hot and tough on your plants. But sunsmart garden designs and water wise habits can help nurse your garden through a heatwave and keep your plants healthier during the hottest parts of the year.

Here are 10 ways to help your plants through a heatwave this summer:

1. Water Wisely

Ensuring your plants have adequate moisture throughout summer is important to reduce heat stress. 

Deep watering early in the morning is best for plant health. This will allow time for the moisture to reach the roots before it evaporates. 

Try to get water as close to the root zone as possible with a watering wand or dripper irrigation. Avoid watering the leaves of plants as this can cause scalding as the water evaporates.

Olla pots, self watering pots and wicking beds are an awesome way to water plants steadily through summer.

Bury an olla pot in your garden bed and fill with water. Surrounding plants will receive a steady supply of water to the root zone.

2. Plant With Sun Protection in Mind

Plant your heat sensitive crops like summer lettuce in the shade cast by exisiting structures such as a fence, the wall of a house or larger plants like trees and shrubs. Positions that allow morning sun but protect from the harsh afternoon sun are ideal.

If your yard is particularly sparse in foliage, aim to increase canopy cover to cool the temperature in your patch.

Consider deciduous trees or climbers on the north or west facing sides of your home such. These will cast shade during summer but allow plenty of light in during the cooler months.

Close planting will also help to support plants through hotter weather as vulnerable plants can find refuge in the shade of their neighbours. Plus, plants naturally release water through their leaves. Close planting helps trap some of that humidity, keeping things cooler overall.

Planting densely can help create a cooler microclimate in your garden bed.

3. Insulate or Relocate Container Gardens

Soil in containers and above-ground garden beds will heat up more quickly than soil in the ground. To mitigate the impact of sun on containers, wrap them with hessian, cardboard or another insulating material.

Try growing a hardy ground cover such as sweet potato to shade out the sides of your raised garden beds. Plant your most heat-tolerant crops on the outer edges of the raised garden beds, leaving the inside areas for your more sensitive crops.

If your plants are in containers, relocate them undercover or to a shady area of your garden. Place them in an area where there is mulch or ground cover plants rather than directly onto concrete. 

4. Install Temporary Shade Structures

Rig up some temporary shade using shade cloth or even umbrellas to keep the direct sun off your plants during the hottest part of the day.

Our insect protection nets and fruit protection sleeves offer 20% shade factor which is a good way to protect plants from the heat of the summer sun while still ensuring they're getting enough light.

5. Protect the Soil 

Ensure you have a good layer of organic mulch or ground cover over your entire garden. It's important that soil isn't exposed to direct sunlight as this will harm the microorganisms and other life in the soil.

Mulch helps regulate soil temperatures, reduces evaporation when you water and will add organic matter to your soil over time, improving its ability to absorb moisture.

6. Build Healthy Soil for Resilient Plants

Building healthy soil is the foundation of a thriving garden and will make your plants more resilient during a heatwave. Composting and the addition of fibre and leaf matter to the soil will help to build healthy, living soil over time. 

Sandy soils, like most of us have in Perth, are prone to becoming hydrophobic and unhealthy. Consistently mulching, composting and adding organic matter to your soil is critical to build healthy soil biology.

7. Boost Plant Resilience with Seaweed

Seaweed is known to help plants weather both heat and cold stress, boost immunity against pests and diseases and stimulate healthy growth both of foliage and roots.

Giving your plants a drink of seaweed tonic can help protect them through intense heat.

Add 2-3tsp of powdered kelp to 10L of water and apply every 2-4 weeks to help plants cope with heat stress.

8. Save the Strongest Seeds

If you notice certain plants survive better than others in hot weather, save the seeds of the strongest plants at the end of the season. That way you can future proof your garden by growing resilient plants that you know will do well in your exact climate.

9. Try 'Sunscreen' for Plants

We apply sunscreen to ourselves when the heat is high, but what about our plants?

When sprayed on the leaves and branches of your plants, Kaolin Clay acts like a natural sunscreen. It can also help repel sap sucking garden pests, including Citrus Gall Wasp.

When used as a 'sunscreen' on plants (such as tomatoes, capsicum, avocado, grapes, mango, stonefruit, cucumber, melons) the clay reflects damaging UV rays but allows light to enter the leaves. This means while protecting plants from sun damage, it doesn't stop photosynthesis or block stomata, the 'breathing' openings.

Dilute Kaolin Clay in water and spray on plants to protect from sun damage.

How to Use Clay Spray

1. Mix 50g kaolin clay powder with 160mL water in a 1L water bottle. The mixture will quickly form a suspended slurry.
2. Top up the water bottle to 1L of water.
3. Spray a film of the mixture over the leaves and branches of your plants, until just at drip point (when the spray has fully covered the surface, and begins to drip or run off).  
4. Repeat at 50% strength every 2-3 weeks or when you can no longer see the clay on your plants.

Tips for success:

• A little goes a long way.
• Avoid using when rain is imminent, as the spray needs time to dry.
• Don't forget to rinse spray equipment immediately to avoid clogging.
  
• Don't spray during flowering as the clay can deter pollinators.

10. Plant More, Pave Less!

Large paved areas are noticeably hotter, amplifying the effects of a heatwave and creating a very hot microclimate in your garden. Consider instead planting your space with water wise perennials, hardy natives and shady trees.

Not ready to plant out your garden? Even an area that's mulched will be cooler than a paved area.

Water features, including ponds, are also a great way to help create a cooler microclimate in your garden. Plus, you'll be providing wildlife (including beneficial insects) with a water source which is crucial for their survival over the summer months.

Create a cooler garden microclimate by increasing your canopy, installing a pond, planting more and planting densely.

Stay Cool this Summer

A combination of short term and long term solutions can help you and your plants fare better over the hottest part of the year. Instead of resisting the weather, look for ways you can creatively adapt – this is a crucial part of being a resilient gardener!