General Information and Care
Although they appear to be dwarf trees, bonsai are not genetically small. They come from regular seeds and tree stock. Pot size, shaping, and pruning all have a part to play in keeping a bonsai miniature, so the care and maintenance of bonsai is truly an art form.
Some of the more popular forms of bonsai trees include juniper, ficus, jade, powder puff, buttonwood, and bougainvillea. Like all other plants, certain bonsai plants are more suited to certain climate zones than others, so you may want to speak with someone at a garden center or bonsai club when deciding what type of tree to purchase. Generally bonsai are referred to as either “temperate” or “tropical,” depending on their ability to adapt to frost and cold. Some can grow indoors, but others will be best suited for the outdoors, and some gardeners recommend keeping all types outdoors as much as possible, with proper protection for tropicals during colder times of year.
When A Bonsai Starts Looking Yellow
Sometimes a bonsai’s leaves will start to turn yellow. While some yellowing is normal, especially with certain species, too many yellow leaves could indicate a problem. If you’re a novice bonsai grower, you may be tempted to worry, but there are some tips you can follow if this begins to happen.
Although there could be a variety of reasons for yellowing bonsai leaves, here are a few of the more common:
Underwatering the tree – This is probably the most common cause of yellow leaves.
Exposure to cold – This can be especially true for a tropical species of tree.
Stress – A sudden move to a different position, especially effecting a change in light, can cause a bonsai to drop leaves.
Mineral deficiency in the soil – This is especially possible for species, like azaleas, that need a more acidic soil.
Solutions to these common difficulties are fairly easy to implement.
Watering Your Bonsai
Watering is crucial to the survival and health of your bonsai. It’s so important to bonsai care that apprentices learning the art of bonsai growing in Japan are given pruning shears long before they’re given watering cans. But don’t let that daunt you. You can learn to water your bonsai well.
If a bonsai’s leaves are turning yellow and dropping, it could be a sign of underwatering. Just like a person, a plant that is not receiving enough water can become dehydrated. While there doesn’t seem to be a hard and fast rule regarding how frequently you water your bonsai – it depends on the type of plant and the type of soil, and you’ll need to check the pot often for dryness – there are a few things to keep in mind.
It’s good to water your bonsai early in the day.
It’s important to water both the soil and the leaves. While it’s true watering the soil is important, and that bonsai develop complex root systems, washing off the leaves can also help keep the bonsai healthy. If you have a bonsai that needs higher humidity, you may need to mist the plant periodically if you have it indoors in the winter too. A mist setting on an outdoor hose can also help you wash the leaves on the tree outside.
Perhaps the most important guidance is this one: once a week, water the soil thoroughly by actually immersing the pot in water. The bonsai will take in what it needs. When the water stops bubbling, the bonsai has had a thorough “drink.” Watering once a week this way should help the plant stay hydrated.
Keeping Your Bonsai Happy
Stress can affect plants, and bonsai are no exceptions. Moving a bonsai from one location to another, particularly from outdoors to indoors, could cause leaves to yellow and drop off. Depending on whether the bonsai is considered temperate or tropical, and depending on where you live, you may need to adjust its indoor location to make sure it’s getting enough sunlight, or provide it with some time outdoors.
It can also take a while for a bonsai that has been recently moved from location to another to adjust to temperature, especially if you’ve made a big move from one climate zone to another. Since so many of these questions are specific to where you live and what type of bonsai you have, it would probably be helpful to check in with an expert. Websites like the Helpful Gardener have bonsai discussion forums set up where you can ask questions very specific to your situation.
A mineral deficiency in the soil will likely be improved by providing some fertilizer for your bonsai. Once again, much will depend on the type of bonsai you have, and a veteran bonsai grower will be best equipped to help you understand what type of fertilizer to use and when.