Caring for Bonsai

BONSAI means “planted in a shallow vessel” or “tray planting”. This art form started in China as early as 1200 years ago during the Tang Dynasty. Plants that are commonly grown as bonsai include pine, juniper, cypress, maple, fig and schefflera. Bonsai have been grown for many centuries by following some basic and simple growing procedures.


Soil should be kept moist, not wet. Smaller pots require more frequent watering. To water, soak pots thoroughly in a pan, tub or sink, then let drain. While soaking, rinse the foliage to clean the leaves. Plants with or sending out new leaves require more water than those resting. In our dry Calgary climate, it is recommended to check the soil daily, to see if watering is required.


Adequate nutrition is essential to maintain the health of your bonsai.
Plant Prod 20-20-20 water soluble fertilizer applied at half strength every 1 to 2 weeks during the growth period (spring and early summer) will keep plants healthy.


Most bonsai prefer indoor temperatures between 15 - 25 ºC (65 - 80 ºF). Some varieties of bonsai will benefit from experiencing cooler temperatures in the fall, for a period of 8 - 10 weeks. During this period, the temperature can range between 10 - 15 ºC (50 - 60ºF). These varieties include pine, juniper, cypress and maple.


Filtered (shaded) natural light is necessary for growing bonsai. Avoid direct sunlight, as it may prove too intense for most varieties of bonsai.


Humidity around bonsai may be maintained by the following procedure. Fill an oversize drainage tray with pebbles (or other non-absorbent material). Then fill tray with water to within 1/2” of the top (so that the water level is just beneath the surface of the top layer of pebbles). Place the bonsai pot on top of the pebbles. As the water in the tray evaporates, the humidity will rise around the bonsai. Water in the tray will have to be replaced as evaporation occurs. To prevent excessive moisture loss from the bonsai, ensure that it is not situated near a heat register or air vent.

Pruning and Shaping

Adequate and timely pruning is essential to good bonsai development and styling. Prune by cutting or pinching back new growth 1/3 to 1/2 or to the desired shape. Root pruning is done when the bonsai is repotted to generate new feeder roots. Frequency and extent of pruning depends upon the variety of bonsai as well as the style and size desired and cannot be adequately covered here.

Branch bending and shaping can be done on some varieties by utilizing bonsai wire. This is a soft textured wire that is wound around branches and then anchored to the trunk. The wire maintains the structure of the branch, as it is gently bent into position. The wire must be left in place for several months in order for the new branch shape to hold. Consult the information counter for details regarding this procedure.


To keep plants healthy, repot bonsai every two to four years. Early spring, just as the buds begin to swell is the best time. Carefully remove the plant and root ball from the pot, soil should be on the dry side. With fork or chopsticks, loosen and remove about 1/2 of the ball, working in from around the edges. Cut off any exposed portions of length. Reposition the plant in the same or new pot and fill carefully and firmly with fresh new soil. The soil should be comprised of 3/4 all purpose potting soil to 1/4 horticultural sand. After potting, water the bonsai thoroughly.

Good Luck!

These much condensed suggestions though basic, are sufficient to keep your bonsai healthy and attractive. You will find much more information in the many publications and internet sites that are available.