Harry HarringtonArtist and Author, Bonsai4me · Author, Publisher, Webmaster, Bonsai Artist

How To Water Your Bonsai In The Summer

25 Jun 2022 · 5 min

Watch on YouTube

4:30

In this instructional video, the presenter explains how to water bonsai trees effectively during the hot summer months. He emphasizes that many species need daily watering, with the frequency potentially rising to two or three times per day when temperatures exceed 30 °C (85 °F) in the UK. To reduce workload and prevent trees from drying out, he teaches a two‑stage watering method: the first pour wets the surface and opens pathways in the substrate, while a second pour ensures the soil mass fully absorbs water. He advises against over‑watering and recommends using rainwater or a pumped 800‑liter water butt rather than chlorinated tap water; thirsty trees can be soaked in a container for 10–15 minutes. Species‑specific guidance is provided: azaleas and other very thirsty, dense‑rooted bonsai benefit from thorough soaking, whereas pines, junipers, and olives prefer drier conditions and should only be watered after the top inch of soil dries. The video underscores that mastering bonsai watering requires experience, daily observation, and an understanding of each tree’s unique needs.

Chapters

In today's video, I'm discussing one of the most important daily tasks for bonsai during the growing season, which is watering. Many species must be watered liberally and at least once a day throughout the growing season. During the heat of the summer, the frequency of watering can increase to twice a day or even 3 times a day. This video is aimed at helping you water your trees in such a way that the period of time between each watering is lengthened. This will help reduce the workload a little in the summer and make life easier for those of you who don't work from home and have the risk of your trees drying out during the day. When you first water a bonsai, the water you apply to the soil surface will run through the substrate, taking the easiest and fastest route. This means that there will be areas of the soil mass that will still remain dry. The first watering should be seen as one that sets up the soil to accept water. When watering, you should avoid watering too heavily. water, particularly if the water tends to run off the dry surface of the soil until it has been wetted. One of the most important things to do when watering your trees is to water twice. The second watering will be the one where the soil is able to accept water properly. Water all your trees a first time and then go back round and water them a second second time, and this is where water will be truly absorbed into the soil mass. I tend to use small bonsai pots for my trees, and when we have hot weather approaching, I will take a slightly different approach with bonsai that are very thirsty or difficult to water thoroughly. Bear in mind here that for us in the UK, temperatures of above 30°C or 85°F are considered hot and require careful watering of our trees. Many enthusiasts use water from the tap without problems. However, it will contain chemicals such as chloramine, chlorine, and ammonia. If you have access to rainwater, use it for your trees. They will thank you. I use a pump fitted to an 800-liter water butt situated at the bottom of the garden. Stand thirsty trees in water for 10 to 15 minutes to really thoroughly soak that soil. The super hydration of the root ball will keep the tree wet for a surprisingly long amount of time. This azalea Shohin bonsai is very thirsty and lives in a very small pot, so has a very dense root ball, so it is soaked in water ahead of very hot Singa, singa. Whereas most bonsai trees will die if allowed to dry out completely and are grateful for plenty of water during the growing season, there are some species used for bonsai that require the soil to be kept on the slightly dry side, even during the summer. Pines, junipers, and olives require a drier environment to keep them healthy. These species should not be watered until the top 1 inch of the soil surface, if not more, is dried out. So don't do it— overdo it with them. There is much more to watering the bonsai in your collection than you might expect at first. It really does take years of experience to learn the nuances of when and how to water a myriad of different tree species and the requirements of individual trees in your garden. But the time spent with them each and every day is also an invaluable way of staying connected and enjoying them.