Surviving the heat

From Sarah's garden to yours

Summer is the most anticipated season for a number of reasons. From time at the beach, holidays from school and work and when most of the vegetable garden harvest grows and the best and brightest flowers bloom, summer offers so much. However, it can be a brutal season.

Our out-of-season rose coloured glasses have us yearning for the balmy days and endless evenings, so we can spend time outdoors and live our best lives. However, as the height of summer rolls around, there is often a reality check. Summer can get very hot. Temperatures above the mid 20° Celsius have us seeking shelter, while the mercury above 30°C often makes news headlines as a heatwave.

The combined effects of multiple hot days over the extended period of summer quickly becomes a drought and we are all urged to curb our water use, just when we really need the cooling effects water can bring. Long hot nights have us losing sleep and feeling grumpy; during the hot days we can quickly become dehydrated and sunburnt. At least we can seek shelter from the worst of it by staying indoors or under the shade of a tree.

Plants in the garden don’t have the luxury of seeking shelter and can only do their best with where they are. Any assistance the garden can get from you at this time of year will make the difference between life and death.

Having the right plants in the right spot

Gardeners often like to stretch boundaries in the garden, by attempting to grow things out of the plant’s comfort zones, either in time or location. A stunning must-have bloom is added to the display in spite of the recommendations on the label, or a desirable edible that prefers a different set of conditions to truly thrive is often optimistically given a go. There isn’t much to lose as plants are expendable so worth experimenting with and, at the end of the day, the thrill of the challenge can be enough of a reward.

However, if things are to go wrong for these risk takers, it will be in the height of summer. A plant that prefers the shade or a cool climate will be the first to succumb when it finds itself out in the full sun on the hottest day. So, if you want a garden that will continue to thrive and look great in all situations, even the hottest days, take the time to research what plants like and need before bringing them home and popping them in your garden.

Plants that don’t mind hot conditions have features that help them cope, such as:

• Smaller leaves to reduce surface area for moisture loss
• Thick, waxy leaves that resist drying out
• Fleshy structures to store moisture within the plant
• Fluffy or pale coloured leaves to deflect excess sunlight
• Deep root systems to reach groundwater

A well-prepared soil

Even before plants are introduced to the garden, it is important to spend time preparing the soil to help them cope in less than ideal conditions. It is good to have a free draining soil, however it does need to have an ability to retain some moisture. The key to healthy plant growth is to ensure there is enough available moisture in the soil for the plant to continually transport nutrients from the soil, up into the plant via the roots, using water as the vehicle for moving the essential food molecules.

Adding plenty of well-rotted organic material is not only a potential food source, but it also works well to retain moisture within the structure of the soil. If things get too dry in the soil, nutrients can become bound up and so the plant is not only thirsty but is also hungry. This can put plants at risk of pest and disease as an unhealthy plant is an easy target that will quickly perish.

Mulching saves moisture

A good thick layer of mulch helps preserve moisture in the soil by reducing evaporation. It also helps prevent weeds establishing alongside your desirable plants, competing with them for the precious water and nutrients.

Always apply a mulch to a well hydrated soil, so you lock the moisture in and not out! Avoid putting mulch up around the trunk or stem of the plant or you could cause rotting. You will still need to water the garden, although less frequently than an un-mulched garden.

The depth of mulch depends on what you are using. There are a range of options and some are better than others:

Good options:

• Pea straw
• Straw
• Autumn leaves
• Arborist chips

Satisfactory options:

• Compost cardboard
• Newspaper
• Bark chips
• Grass clippings (weed and seed free)
• Stones and pebbles

Avoid:

• Plastic weed mat
• Hay

Good watering makes all the difference

How you water can determine if your plants live or die in hot weather. Water in the cool of the morning or early evening so the maximum amount of water is absorbed by the soil and not lost through evaporation.

A good deep watering every few days is better than a short sprinkle every day. However, keep an eye on the garden and water plants that are beginning to show signs of stress.

Always check the temperature of the water coming out of the hose. If left lying out in the sun, hose water can get to near boiling temperatures and will harm your plants. Coil hoses up or store on a hose trolley when not in use to reduce the risk and improve the longevity of the hose. A hose stored in its own retractable hose reel, preferably UV resistant, is another great way to keep the hose out of the direct sun.

Avoid watering on the leaves as this can scorch the leaves like a magnifying glass in the full sun, while also creating a humid environment desirable to fungal diseases. It is best to water directly on the soil where the plant needs moisture the most. However watch for soil splash onto the leaves as this can also encourage fungal diseases.

A hot dry soil can form a hydrophobic crust that will repel water. To break the crust water the soil lightly and allow it to sink in, softening the soil and making it receptive to larger quantities of water, then go back and water deeply.

An irrigation system is a great way to ensure the garden is watered consistently, without waste, during a hot dry spell, and even when you aren’t available to be in the garden. In hot dry periods, it is even more important to avoid yo-yo watering where the soil bounces between being too wet and then too dry.

During the heat of summer, it is prudent to check for local water restrictions before watering your plants. If you need to save water, grey water can be used on ornamental gardens, so long as the cleaning products you use are environmentally sensitive. For edible gardens, catch wasted sources of fresh water, like using a bucket to catch the water from the shower before it heats up.

Look after the gardener

And finally, keep the gardener safe and well in the garden. Stay hydrated by drinking plenty of water. Wear a wide brimmed hat, regularly apply sunscreen and take plenty of breaks in the shade. Avoid working in the heat of the day and leave jobs that demand lots of energy to the coolest hours.