Bonsai Watering – tips for beginners

  • Bonsai should ideally be checked twice a day to assess soil moisture and water requirements. The aim is to water bonsai in the Goldilocks zone – not too wet, not too dry.
  • Only water when the tree is ready to be watered. Continued over watering will have a detrimental impact on bonsai health. Over watering can kill your bonsai. Under watering will kill your bonsai.
  • To tell if the tree is ready to be watered:
    • The top soil should be dry
    • Stick a wooden chopstick into the soil and see if it comes out dry, slightly moist or wet. If its dry or very slightly moist you can water.
    • Feel the weight of the bonsai. Get used to the weight of each bonsai, pick up tree and if it is heavy there is water in it, if it is light then tree is dry
    • Anything bonsai that’s soil is more than slightly moist should be left alone. The only exception to this is if it is going to be a hot day and you are pre watering because you can’t water later. This should only be done occasionally in summer.
  • The goal of watering is to water until all the soil is wet, let the soil dry until the surface soil is just dry, then water again.
  • Water with a soft rain rose head on a hose or watering can. Watering by hand is superior to a watering system.
  • Water the whole tree including the leaves.
  • Water until all the soil is completely saturated. To achieve this; water until the water runs through the pot, leave the bonsai until the water has finished running through, then completely water the bonsai again. Then repeat this process a third time. All the soil must be saturated.
  • Be aware of dead spots (spots that water can get to). Behind the trunk, slopping pots, over packed areas, pot bound bonsai are all at risk of this.
  • The amount of water stays the same but the frequency should change to suit the tree or conditions.
  • Watering in the morning is best, watering in the evening is ok as well. Be careful watering in the middle of the day, droplets on leaves can burn leaves.
  • Learn what your bonsai needs. They are all going to need slightly different watering frequency. This will change from day to day depending on tree species, weather conditions and the time of year.
  • Tree species, size, pot type and shape all impact watering requirements.
  • Learn the environment where your bonsai are. Areas that receive all day sun will require more watering than others.
  • Frequency of watering is affected by seasons. As a general rule:
    • Summer: watering every day or as needed very hot days may require three or four waters
    • Autumn: every one to two days
    • Winter every second, third or fourth day. Assess the bonsai every day.
    • Spring: every one to two days
  • Type of tree will affect the amount of water it needs. Junipers are hardy with small leaves and have adapted to living around rocks. Australian natives love water. Some can be grown with a water tray under them. It is hard to over water many Australian natives.
  • Do not routinely completely immerse or dunk trees as this can leaches soil and the soil will become hard and calcified. Only completely immerse if it is an emergency, tree is root bound or that type of watering suits the species i.e. some Australian Natives.
  • Tree should be watered pre and post being inside as air conditioning and heaters will dry out trees due to decreased humidity. Note: Bonsai must live outside, only bring them inside for display for less than 48hrs.
  • Watering systems are a good backup or when you are going on holidays. For best results water by hand and use watering systems occasionally.
  • Enjoy watering your bonsai, it’s good for your mental health.

PDF Download – Bonsai Watering Tips For Beginners – MBB 2020

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