Bonsai is a set of practices used to shape a tree artistically. Specifically, Japanese bonsai attempts to produce pot- or container-grown miniature trees that imitate the shape and structure of real-size trees. Common tree types used for bonsai are ficus, cherry blossom, redwood, juniper and boxwood. Like any other plant, your bonsai is susceptible to the effects of underwatering if its cultural needs are not met.
Underwatered bonsai tree – Signs and how to revive
Signs of an underwatered bonsai tree
Underwatered bonsai trees will develop wilted and dry leaves that become crispy over time and eventually drop off. Other common signs include curling leaves that turn brown at the tips, premature leaf drop, and leaf scorch.
How to revive an underwatered bonsai tree
If you catch the underwatering before it has gone too far, you should be able to revive your bonsai. To do so, place the tree, in its container, in a basin or sink of water so that the water covers the entire pot. Leave it for at least five to 10 minutes so that the soil can become properly saturated. Once all of the soil has been wet and the roots have had access to sufficient water, remove the pot from the basin and allow any excess water to drain properly from the pot. This is important, as you do not want the tree’s roots to stand in waterlogged soil. Thereafter, check the bonsai tree daily and try to keep the soil damp, but not wet.
Further steps to revive your underwatered or dying bonsai tree:
1. Trim off any dead parts of the tree.
Use sharp pruning shears to remove any dead, dried or wilted foliage, stems and branches. If you are trimming branches, cut them back all the way to the trunk.
2. Trim off damaged or dead roots.
If the tree has sustained considerable damage from underwatering, you may need to remove it from its pot to prune the roots and repot it. Check the root system thoroughly and use sharp shears to prune away any infected, wilted, or damaged roots, which should be cut back to the root mass. Only firm, white roots should remain; these are the healthy roots.
3. Inspect the cambium tissue.
The cambium is a layer of plant tissue, just beneath the bark, that is responsible for the secondary growth of stems and roots. Scratch away a small section of bark to check whether the cambium is green, which is an indication that the tree is alive and healthy. If this is the case, there is a good chance that your bonsai tree can recover from underwatering.
4. Repot the bonsai tree.
If poor soil quality has contributed to the underwatering problem, you may need to repot your bonsai tree. Over time, soil can become depleted of nutrients; it could also be too well-draining, meaning that the roots do not get sufficient time to absorb water before the soil dries out again. Prepare your container and fresh potting soil of the correct type for your bonsai and repot the tree. Water it after repotting it, to settle the soil around the roots.
5. Amend your watering techniques.
Water your bonsai tree regularly, but do remember to allow the soil to dry out slightly between waterings, as the roots also need access to oxygen. Check the soil regularly and, if the top layer is dry to the touch, water your bonsai again.
6. Place the bonsai tree in a partially shaded location.
Position the bonsai tree in a partially-shaded spot that gets at least four to six hours of sunlight daily. Choosing a well-ventilated area will also support its recovery, although it will not appreciate strong winds. During winter, place your bonsai tree in a south-facing window so that it can still get adequate light.
Allow your bonsai tree some time to recover and regenerate. It may take until the next growing season before it shows signs of a full recovery.
How long can a bonsai tree go without watering?
Bonsai trees are quite hardy when it comes to watering, and most of these trees can go without water for up to two or three weeks. They may suffer minor damage within such a period, but with a good soak and extra care, a bonsai tree can return to health after a few days.
Bonsai tree care
A bonsai tree’s watering needs will depend on the local climate as well as the tree’s container, species and overall health. Do not let the soil dry out completely between waterings; the top layer of soil can be dry, but the lower levels should remain slightly damp. Keep in mind that, since bonsai trees are grown in shallow pots, their soil dries out faster than that of other house plants.
Pruning is what keeps bonsai trees small, and indoor trees should be trimmed or pruned back whenever there are a couple of inches of new growth. Outdoor bonsai trees need to be pruned during the growing season of spring and summer. Remove broken branches and cut off any twigs that have more than four nodes. Shape the tree and improve its aesthetic by removing branches growing in the wrong direction and those that are too close to the base of the tree.
Average bonsai trees only need to be watered every two to three weeks during the spring and summer months, and somewhat less during the autumn and winter.
Bonsai trees are widely popular for their aesthetic value, and they epitomize the superior standards of Japanese traditional arts. Tree varieties that are often made into bonsai trees include juniper, ficus and redwood. Like most plants, bonsais are prone to underwatering – possibly even more so, because their pots are shallow and do not hold a lot of soil. Common signs of underwatering include wilted, curled or droopy leaves that become crisp over time and eventually fall off. To revive an underwatered bonsai tree, give it a proper soak in a basin of water for five to 10 minutes so that the moisture can reach through the entire root system.
Image: istockphoto.com / SasinParaksa