Why Do Young Trees Need Watering?

Young trees can take a few years to fully establish, especially those in urban environments. Root balls are tightly packed to make transporting new trees easier, but it does mean that their roots can take a little longer to spread out. While mature trees can lengthen their roots to seek out water during drought, young trees have smaller root systems, so often need a little extra help.

Without watering, young trees run the risk of dying during very dry and hot spells, or can struggle to reach their full potential, meaning they don’t get to properly establish, thrive and provide their many benefits, from cooler streets, to cleaner air and enhanced biodiversity.

What Happens When Trees Don’t Get Enough Water?

Much like us humans, trees start to feel dried out when they don’t get enough water. Long periods of dry, hot weather can restrict important processes like photosynthesis from taking place. Extended periods of drought can also lead to permanent cell damage in trees, which can be detrimental to younger trees, especially if they start to lose whole shoots, branches or roots.

The signs of drought can vary from species to species, but when faced with long periods without sufficient water, the leaves on trees can turn brown or wilting, canopies can thin out, and bark can split. In some cases, like we have experienced recently in the UK, drought can also lead to premature leaf fall.

Why Does Watering Trees Matter for Cities?

During drought, we risk losing a number of the key benefits urban trees provide. Less shade from leaves exacerbates the urban heat island effect and trees facing long-term drought can fail to grow as tall as they should, providing less shade in the long term. It’s not just shade, though. Transpiration (the process of trees releasing water through their leaves) is minimised when trees are thirsty, meaning we don’t benefit from the cooler air that transpiration provides.

Air pollution is also a major issue in the UK, with up to 30,000 premature deaths per year linked with the air we breathe. We know that trees can protect us from air pollution, removing harmful pollutants from the air, but this ability is reduced when trees don’t get enough water.

How To Water Urban Trees

The good news is that you can help young urban trees near you thrive this summer. Our team has been working hard to water new trees over the years so they establish and thrive, and has found these tips incredibly useful:

• Give young trees at least 50L per week in warmer months
• Water your trees in the early morning or late evening when it’s cooler to avoid losing water to evaporation
• Use watering pipes and bags where available to give young trees the best access to water
• Add mulch to the base of your trees. It helps retain water, keeping the ground moist and also prevents root competition
• If you can, source your water sustainably. Rainwater is a great option, but greywater from your washing up, baths or showers works just as well! 

How Can You Help Urban Trees Thrive?

Now you’ve learnt the importance of keeping urban trees watered this summer, it’s time to take action. If you have a young tree on your street (usually the trees still supported by stakes), you can keep a close eye on it this summer and give it an extra drink during hot weather. Your care could make all the difference!