ADJUSTING TO A VOLATILE CLIMATE

Gardening in the future may require you to grow different plants and grow them in different ways.

The increasing volatility of our climate is challenging us all to adapt.

We must learn new ways of gardening and reconsider what plants we choose to grow. 

Climate change has different potential implications for gardeners

Cooler areas are becoming warmer – e.g. plants that were previously most suited to the subtropics may in future be more suited to warm temperate climates.

Different rates of warming – warming will be different in different regions. Some areas will warm faster, and others will have delayed warming.

Change in moisture – the ‘usual’ soil moisture and humidity conditions may become wetter in some places and drier in others.

Unpredictability – more extreme weather events are likely e.g. cyclones, floods, heat waves, extreme heat or cold, increased winds, higher or lower rainfall, etc.

It’s More Than Dealing with Extreme Weather  

Climate change can impact gardeners in other ways besides extreme weather events. It will make gardening more challenging for all of us.

Shifting seasons can impact the timing of pollination – flowering times may not align with pollination times because insects may emerge at a different time than usual (before or after the plant flowers). Reduced pollinator activity also leads to reduced food crops.

Plants can become more vulnerable to pests and diseases. Increased humidity encourages some diseases.

Ecosystems can be compromised if weeds flourish in a warmer climate and outcompete garden plants.

Droughts can increase soil degradation.

Plants adapted to drier conditions may die via floods, heavy rains, and waterlogged soils.

Edible plants may be damaged by heat stress from hotter growing seasons.

Plant selection will be more important as growing zones shift.

It Isn’t All Bad News

Even if you cannot do all the things you used to do in the garden, some things may become easier to do in the future.

For example, you may find that some plants that were once easy to grow become harder to grow, but other plants that were once challenging become easier to grow.

The key is, like plants, we must all find ways to adapt.

Choose Your Plants Wisely

To garden successfully with climate change, you need a broad knowledge of plants. Research your plants well and choose those that are resilient, adaptable to environmental changes, and best suited to your region.

For example, don’t try to grow tropical plants in cold regions if the change has not been great enough for these plants to grow well yet.

Learn And Use Different Gardening Techniques

If you’ve been gardening for a long time, it can a challenge learning to do things differently. But there are easy fixes that don’t require much effort.

Things you can try:

Choosing and Using Plants

Use plants to alter the microclimate in your garden. The heat around a building can be lowered by growing evergreen climbers on the outside.

Use dense shrubs to insulate your home and trap air pollution. Consider growing hedges – choose hedging plants that are tough and adaptable to change.

For garden beds, choose perennials rather than annuals. These have deeper root systems that tap into the water table. They are less likely to become drought-stressed and require extra watering. Also, the soil doesn’t need to be dug over regularly so it retains its integrity.

Choose plants or cultivars that suit a slightly warmer climate than those which grew in your region years ago.

Select plants with a proven track record of heat tolerance in extreme summer heat.

In areas likely to experience more frequent flooding, choose plants that can withstand waterlogging e.g. some ornamental grasses.

Where possible, choose resilient plants adaptable to a wider range of conditions (flooding, drought, extreme temperatures).

Choose plants with multiple benefits (cool the garden, reduce pollution, provide habitat, etc.).

To overcome pollinator and flowering misalignment, create a biodiverse pollinator garden with a range of plants flowering throughout the year. Avoid pesticides and weedicides to protect beneficial insects.

Using Water

For trees and shrubs, dig a shallow moat in the soil beneath the edges of the canopy to capture water runoff. Add a soil wetting agent every few months when watering to stop soil becoming water repellent.

For more efficient watering, place plants with similar watering needs together.

Water heat-stressed plants with a seaweed solution combined with a wetting agent.

During hot weather, water in the coolest part of the day so plants can absorb moisture, and foliage can dry off before it gets hot. Watering early also reduces the risk of disease and lowers evaporation. Consider collecting rainwater.

Water deeply to encourage deep root systems with greater drought resilience.

Consider misting plants with a fine mist on very hot days. Do this when plants are in the shade.

Prepare for heat spikes by watering soil deeply in advance. Most damage is done to plants when temperatures suddenly rise significantly and there is not enough soil moisture for roots to tap into.

Avoid overwatering plants in containers on very hot days. Water will fill the air spaces, and they will suffocate. It is better to water and allow the water to drain through before watering again.

Prune, water, and feed at different times to what you have traditionally done.

Pruning and Feeding

Don’t feed heat stressed plants until they have put on signs of new growth.

Don’t be tempted to prune off dead or dying branches on trees and shrubs during excessive heat. Some may send out new buds later, but even if they don’t – they offer protection from direct sunlight to the trunk and healthy stems.

To prevent heat stress, consider pruning flowers and perhaps the most recent set of new leaves of heat-prone shrubs before the weather gets too hot.

Sheltered Environments

Some plants typically grown in flat garden beds might need to be grown in raised beds or in pots in future if your area becomes more prone to flooding. Slopes, rocks and trees can also be used to create shelter and to protect plants from extremes.

Make use of temporary shade, e.g. protect heat sensitive plants and fruits like tomatoes and cucumbers with portable screens of shade cloth during heat spikes and heatwaves.

Create windbreaks and shade in larger gardens with shrubs, hedges or fences – this reduces moisture loss and creates a more conducive environment.

Make sure that your garden has good airflow, even when protected by hedges etc. Leave gaps or use slats for fencing. Choose plants that allow airflow through the hedge. This will help prevent fungal diseases if a garden becomes too sheltered.

Encouraging Healthy Soil

Add organic matter to soil to improve soil health (moisture holding ability, structure, fertility) and create a buffer against weather extremes.

Apply a layer of organic mulch to stop soil and plant roots from drying out. Mulch regulates the soil temperature, retains moisture, and reduces evaporation. Always apply mulch onto damp soils.

Amend sandy soils or those with poor water retention ahead of extreme temperatures by adding organic matter e.g. compost. Do this regularly.

For lawns, apply a liquid wetting agent several times over summer. Water it in well. Turn on sprinklers for a short burst during hot days to cool the lawn (rather than to water the roots).

Avoid soil disturbance as much as possible. It compromises soil structure and discourages microbial activity of soil microorganisms (e.g. fungi, bacteria, nematodes) essential for healthy soil.

Using Containers

Grow plants in pots or containers and move them to more protected positions as needed, e.g. onto a shaded deck, to avoid extreme cold or wind.

For larger immovable potted plants, consider wrapping hessian or cardboard around the pots to prevent them from overheating.

Other Thoughts

Collect seeds from resilient plants in your garden – those that have adjusted well to more difficult environments.

Keep an eye on weather forecasts and act before extreme weather events.

By making some, or all, of the above changes – you can continue to enjoy your garden regardless of the conditions.

Discover More

Want to learn more about how to successfully grow plants in different environmental conditions? Then you’re in the right place.

Choose from a range of self-paced 20 or 100 hr horticulture courses provided by ACS Distance Education. Contact [email protected]