Forget about how you water other house plants. Bonsai are different, but not difficult. Bonsai have small, confined root systems and need to be watered more frequently than a regular houseplant. Learning to gauge the water needs of your tree is one of the most important skills you'll develop as a bonsai gardener. Use the answers in this FAQ as guidelines; however, they should not substitute the detailed care guide you may have received with the purchase of your bonsai.
How often should I water my bonsai?
No single watering schedule can be applied to a bonsai. Unlike a houseplant, bonsai can dry out quickly because they are planted in coarse soil and shallow pots. There are many factors that will determine your watering frequency: for example, temperature, lighting conditions, type of soil, and the changing season. After a few weeks and a perhaps little research, you will get to know your bonsai and become familiar with its watering requirements.
How do I know when my bonsai needs water?
The best way to tell if the bonsai needs water is to feel the soil. Stick your finger a half inch or so into the soil. If you do not feel much moisture in the top half inch of the soil, then it is likely time to water your bonsai. Remember, this is a general rule, but it may not apply to all types of bonsai. For example, a succulent bonsai such as a Jade will welcome a dry period. That's ehy it is important to research your bonsai and read your care guide.
With time, you will get to know when your tree needs to be watered by observing the foliage or just by the weight of the pot. The drier the tree, the lighter it will feel.
How should I water my bonsai?
There are two methods to watering your bonsai. The overhead watering method
uses a hose or watering can. Make sure you deliver a fine spray of water, otherwise a strong blast of water can dislodge soil or damage your bonsai. We recommend using a watering can rosette for just the right spray.
To water, simply pour over the plant and allow it to flow into the soil. If water puddles on the surface of the soil, let it drain into the soil and water again. Keep going until water begins to run out of the drainage holes in the bottom of the pot. Have a humidity tray to catch the dripping watering and protect your furniture. Keep watering for a minute or two more to make sure the entire soil mass is soaked.
The immersion method is the most popular and cost--effective method for watering an indoor bonsai. Fill a bucket or sink full of water to the point where the water should be about one inch up the trunk of your bonsai. As you submerge your tree, you will see bubbling from the root ball. Pay close attention. The vigorousness of this bubbling will indicate just how much water your tree needs. As you become more in tune to your bonsai, you will come to recognize various levels of bubbling. If your tree produces bubbles like boiling water, chances are that you're not watering enough. If it bubbles slowly, you may not be watering enough. Keep your bonsai immersed until bubbles stop rising to the surface. When they are done, so are you. No more bubbles means that the root mass is thoroughly soaked. Slowly remove the tree and allow it to drain.
While submerging your tree for a few minutes won't hurt it, it may wash soil, rocks, and fertilizer away. Make sure you keep plenty of extra supplies on hand. Humidity trays can help too. A soaked bonsai may need to drain for several minutes, and humidity trays can help trap the water. If you are displaying your bonsai on fine furniture, you should consider placing your tree on a well-matched bonsai stand. Why risk water damage or other unsightly water marks?
Should I water all my bonsai at the same time?
Probably not. Watering daily without knowing the condition of the bonsai soil could result in over watering. Some bonsai may require water on a daily basis, especially during hot summer days. Follow the steps above to determine if your bonsai needs water.
What time of day should I water my bonsai?
We talk to a lot of bonsai gardeners, and the only rule of thumb is to avoid watering during the hottest time of the day when your bonsai is exposed to full sun. Try watering your bonsai in the late afternoon or evening to ensure that your soil remains moist all night and into the morning. If it is very hot during the day and your tree is in the full sun, it may need an additional drink. But, take care not to water or splash moisture on the foliage if watering your bonsai during full sun. The sun's rays may cause water droplets to act as a lens and potentially burning its leaves.
Can I use regular tap water?
In most cases, the answer is yes. If you can drink your tap water, you can use it to water your bonsai. If you have hard tap water (leaving white salt deposits around the pot or trunk), you may want to occasionally use collected rain water, but this is not essential. The purpose of the rain water is to rid the soil of any build up of salts. A tip: if your tap water has a lot of chlorine it is a good idea to let it sit overnight in the watering can. That way the chlorine evaporates and your bonsai will appreciate the clean water.
Do I need to mist my bonsai?
Misting is a method of creating humidity for your bonsai. Misting will clean and refresh foliage, but it is not a substitute for watering. When misting, only give the foliage a brief spritz. Do not drench your bonsai. Misting only creates a temporary humid atmosphere. If you are going to mist your bonsai, consider using a gentle water mister like the Haws Water Mister.
Most indoor bonsai require humidity, especially during the winter months. In winter, central heat will dry out the air and any moisture in the room. Fortunately, there are some easy and inexpensive methods to increase humidity around your bonsai.
To increase humidity by evaporation, place your bonsai on a flat tray filled with river pebbles and water. The tray should be larger than your bonsai pot by an inch or two on each side. Fill the water regularly. As it evaporates, the humidity around your bonsai will increase. Stones provide a decorative surface for displaying the tree and elevate the bonsai pot above water to prevent root rot. Humidity trays make watering simple, provide essential humidity for your tree, and protect furniture from stain and damage. For a few dollars it is worth the investment.
Do I need to use a special bonsai watering can?
No, but it will be one of the best investment you make. Rarely do you hear bonsai gardeners comparing notes on their favorite watering cans. However, serious gardeners know that a quality watering can is an essential tool and will make watering bonsai a pleasure rather than a chore.
Watering cans may seem to function in essentially the same way, but there are some major differences among them. The most important differences for a bonsai gardener are the length and shape of the spout. A standard-sized spout is ideal for all-purpose watering and fertilizing, but a brass rose spout, sometimes called a rosette, works best for mimicking a soft rain shower, which is what your bonsai is accustomed to and will help it thrive.
We recommend Haws English watering cans, which are famous for their splendid designs and generally considered the best watering cans money can buy. But more importantly, they are perfect for watering bonsai. The long curve spouts are designed to control the flow of water. The s mall holes in the rose soften water flow so it's gentle enough for tender bonsai seedlings and won't wash away the soil every time you water your bonsai.
How do I water my bonsai when I go on vacation?
If you're leaving for a few days, you probably have nothing to worry about. Bonsai like to get a little dry in between waterings, but they must never be allowed to become bone dry. If you are leaving for several days or weeks, ask a friend to come over and water your bonsai. There is no substitute to having a person water your bonsai.
You can purchase a "vacation drip" watering tool, but these should only be used in the event a friend forgets to water your bonsai for a day or two. The bonsai dripper allows a slow trickle of water and never lets your bonsai accidentally dry out. We don't recommend using a watering drip for several weeks at a time.
Another vacation option is to water your bonsai and then wrap a plastic bag around the pot and soil. Close the bag around the trunk with a wire tie. You do not have to enclose the entire bonsai, just the soil so it does not dry out. You don't want to place your bonsai near the hot sun, but you do need bright light and a place where your bonsai will stay cool. If you plan on trying this vacation method, please do so before you go on vacation. This will allow you to observe your bonsai health and see how long you can it can go without water.
Remember, your bonsai is not a plan and it will not revive itself with a splash of water like a plant will. Your best option is always to have a person monitor and water your bonsai while on vacation.