A Beginners Guide to Watering your Bonsai by David C
“To water or not to water that is the question”
One of the fundamental requirements of your Bonsai is water. If you think that you are the only one who is puzzled by the how, when and why of watering then think again. Many people starting their bonsai journey are naturally and rightly concerned as to their bonsai’s watering requirements. However, no- one can actually tell you how often you will need to water your trees. That’s simply because there are many factors that influence your tree’s water usage. Hopefully these few suggestions will assist you on your way.
How to tell if you tree needs watering
The simplest, easiest and most important way is to look i.e. using you finger, scrape away some of the soil in the pot to see if the soil underneath is dry or moist – if it is dry then water, if not, leave it until it is dry. However this may mean that if the soil is wet in the morning and therefore does not need watering, it may be dry by the afternoon and will need watering.
The other important issue with watering, is that when you do water your tree, make sure that you really water it thoroughly to the point that water is running out of the drainage holes in the bottom of the pot. Also it is important that you water all sides of the tree so as to ensure that all the roots receive water not just the ones on one particular side.
Factors that influence watering requirements
There are a number of factors that you do need to consider in determining how often you need to water your trees. These factors include but are not limited to-
Heat – Summer conditions here in the sub-tropics will obviously mean that you will need to water more often, perhaps even two or three times a day.
Wind – Windy days, even in Winter, will dry your trees out very quickly so make sure that you check.
Rain – Be mindful of how much rain you have received. Sometimes you think that you may have received enough rain to save you watering but be aware that if your tree has a full canopy of leaves it can act as an umbrella preventing lighter rain from penetrating down into the soil.
Type of tree
Flowering trees- Generally speaking a Bonsai in flower will demand more water. This is especially true for Azaleas and Camellias. If allowed to become dry, the flowers will quickly wilt.
Deciduous trees – During Winter their demand for water will decrease but will still need watering when dry, just not as regularly. However, just be mindful that during the growing season i.e. Spring and Summer, deciduous trees generally require more water than evergreen trees.
Water lovers – Some Bonsai just love water, in particular Swamp Cypress and Wisteria. Enthusiasts even place these varieties in a tray of water all through the growing season. Please do not do this with other species.
Location – Your Bonsai will love sun, after all it’s a tree and should be located where it receives plenty of sun. However this means that it will dry out more quickly.
Size of pot – This also relates to the location of your tree. Generally speaking, bigger trees (in bigger pots) will withstand longer periods in the sun. Trees in small pots, while still needing sun, will only tolerate morning sun. For example if your tree is reasonably small (less than 30cm) it will not survive being located in full sun all day in the sub-tropics.
Look before you water;
Do not water if the soil is still moist/damp; and
Water thoroughly when you do water.
The above points are only meant as a guide but I hope that they do assist you in understanding your trees water requirements.