Considering the fact that a bonsai tree can technically outlive its owner, you surely want to get the most enjoyment possible out of it by keeping it healthy. Because bonsai are made of normal plant species, they can vulnerable to many of the same ailments as the flowers, shrubs, and trees in your yard. Whether you’re caring for your existing bonsai or getting ready to purchase a ready-made tree from us these tips will help you recognize and solve a bonsai health problem quickly:
- Yellowing or drying leaves: often a sign of over- or under-watering. Overwatering is a frequent killer of bonsai, so be sure to maintain a balance, watering thoroughly once the top half of the soil has begun to dry.
- Damaged leaves: a sign of pest infestation. You want to take action quickly, as pests can destroy a bonsai in short order. Aphids are the most common bonsai pest, but these trees can also suffer from insects such as caterpillars, scale, and red spider mites. In some cases the pests can be removed manually or by wiping the leaves down, or you can use a surface or soil insecticide.
- Swollen bark: this can be a sign of canker or scab disease, typically caused by problems with fertilizing or pruning improperly. The diseased portion must be cut away and wound paste put on the affected area.
- Visible pests or insects: these must be identified and removed. Scale can be taken off by hand, and aphids may be washed off gently with a hose. Other pests will require chemical removal.
- Falling leaves or needles (in the wrong season): leaf fall can be due to black spot, leaf spot, or rust. If any of these diseases are present, spots will appear on the leaves and they will eventually drop. Remove affected leaves and apply fungicide.
- Dieback of branches: if branches and shoots begin to die away, starting at the tips, this can be a sign of mold or mildew. Affected areas must be removed and a fungicide applied.
- Instability in the pot: if the plant wobbles in its container, it may have a weak root system, possibly due to over-watering. Adjust water administration.
- Slow growth: poor or stunted growth can be an indicator of scab or canker disease, or root rot due to poor drainage. In the case of root rot, prune affected roots and move tree into new soil.
- Branches that droop or are wilted: drooping shoots can have a number of causes including mold, mildew, or chlorosis (caused by nutrient deficiency, commonly iron).
- Black, red, brown or other colored spots on leaves: spots of any color on bonsai leaves are not normal and are typically signs of fungi. Fungal infections spread quickly, so the infected leaves must be removed and a fungicide applied to the rest of the plant.
It’s not difficult to recognize an unhealthy bonsai if you know what you’re looking for. Once identified, most problems are treatable, allowing your bonsai to give you many more years of beauty and joy!