Heatwaves during British summers appear like they are here to stay. Hosepipe bans and perilously low water reserves leave many gardeners worrying about how they can keep their outdoor plants alive, alongside responsibly using our most precious resource.
Here at Muddy Trowel, we want to reassure you that it is possible to look after your plants during a drought and keep them looking healthy and maximise how you use the water you use and reduce waste.
- What to do in an unexpected or prolonged summer drought
- A little refresher on watering in general
What to do in an unexpected or prolonged summer heatwave
Follow these three golden rules to respond responsibly to water shortages and droughts in your area.
1. Change your plant’s environment
We can’t control the weather. However, we can influence the environment our plants live in.
Potted plants and those living in containers are more susceptible to drying out because the plant roots cannot search for water beyond the container walls. Containers also have a limited quantity of compost that can retain water.
The following steps can help you look after your outdoor plants during a drought and reduce the need to water your containers as often:
- Move containers to a more sheltered spot (sheltered from direct sun and wind). If you don’t have a sheltered spot, consider improvised shading, parasols, sun sails and windbreaks. These will keep your plants protected from fierce sun that can scorch leaves, accelerate water evaporation, and breezes that wick away moisture.
- Group garden pots and containers together to create a protective microclimate. This makes watering easier but also helps plants benefit from the humidity they create together. We advise leaving a bit of space between your containers to allow air to flow around the plants and prevent mildew from developing on the leaves.
- Mulch or top dress around the base of your plants. You can do this with gravel, stones or pebbles, straw, shredded paper or better still compost or well-rotted wood chippings. This is equally effective for potted plants and flower beds and borders. The mulch helps retain water in the soil below and stops the surface of the soil from baking and becoming hardened. This means when you do water, the water will be absorbed into the soil rather than running off it.
2. Treasure every drop of water
Many of us use drinking water from our mains to water our plants. For those of us lucky enough to be able to capture and use rainwater, this becomes an invaluable resource for all plant watering. Plants prefer rainwater too. If you live in rental accommodation or apartments, there is often little alternative or option to install rainwater capture tanks.
So, how can you use this precious resource more wisely? Here are a few practical tips:
- Place pot saucers under your garden pots. This enables your containers to soak up any excess water that would otherwise drain away when you water them.
- Use grey water instead of tap water. Grey water is water you’ve already used to do the washing up, washing the car, or even washing yourself. If you use a shower over a bath, stick the plug in whilst you shower and scoop up the grey water to use on your plants. They won’t care about a bit of suds, just make sure it’s not too hot before you water them.
- Make a grey water cocktail (for your plants). It sounds a bit grim, but if you can get a large watering can or 15 to 20-litre water container and get into the habit of topping this up with your washing up water, dregs from leftover drinks, shower or bath water, then you can give your plants a really good drench. Chucking a glass or two of water into your containers or on your border every day might make you feel you are watering adequately, but it’s not enough to penetrate the soil to any meaningful depth. Your plants will benefit much more from less frequent but larger volume watering.
- Timing is everything. Sunrise or sunset watering is the most effective way to ensure your plants soak up the water as these are cooler parts of the day. Water won’t evaporate off and is less likely to scald the leaves.
3. Reduce plant stress during a drought
Plants with larger leaves and masses of tall, lush foliage will suffer more than most as they need more water to sustain their height and structure. In addition to this, they will lose more water by transpiration through their leaves (the equivalent of plants breathing in and out) owing to their larger leaf surface area.
It’s not unusual to see outdoor plants wilting in excess heat. This is part of a protection mechanism they adopt to reduce water transpiration through leaves. You may well see them perk up and stop wilting during the cooler parts of the day and during the night. However, if your plants aren’t recovering and remain wilted, you will need to give them a helping hand.
Here are a few things you can do, some are more radical than others, but extreme drought sometimes calls for extreme action:
- Reduce or stop fertilising your plants. Feeding your plants with fertilisers during a drought can do more harm than good. Watering them is the priority. Adding fertiliser whilst watering can put them under more stress as they try and expend energy on growing new leaves or developing flowers or seeds. Try to help them focus their efforts on survival rather than new growth or reproduction and this will improve their chances of weathering out the drought.
- Cut back foliage and flowers. This is very much a last resort as we know this is brutal. The reality is that by reducing the height and volume of your plant above ground, the pressure on the root system to supply the plant with water and nutrients is greatly reduced. If a plant is repeatedly struggling in prolonged heat and dry weather, then reducing its foliage to a third of its original structure can reduce stress and help it to save energy and recover. This is most effective amongst herbaceous perennials and shrubs. Don’t worry they will bounce back!
- Avoid going from drought to flood. Too much watering is as damaging to a plant as too little. Try to maintain the frequency of watering throughout a drought and water well and deeply but check the moisture of the soil before you water to ensure you aren’t overwatering.
A little refresher on our guide to watering your plants
If you’d like to learn more about how to approach watering year-round and additional considerations for container gardening, take a look at our Guide to Watering. This provides you with handy tips and gives you a checklist of what to consider when you are choosing and caring for your plants.