Learn About Bonsai Tree - Seasonal Care !

Spring Care

Spring is the time when new bonsai are started. It is the time for any pruning and training of last season's bonsai. The plants then have a whole growing season to readjust to these changes. 

Summer Care

Bonsai are very sensitive and thrive best in localities that offer cool nights, sunny days, and mist or rain almost daily. Most of the United States does not have this climate, so special provisions must be made to compensate for the lack of desired climatic conditions. Extremes in light, rain, and wind are to be avoided.

Place your bonsai on a platform or table in your garden where the plants can receive 3 to 5 hours of direct sunlight a day. The site should be shaded, preferably in the afternoon. If the area is subject to drying winds, put up screening around the plants to protect them. Screening also serves to provide the plants with shade.

Water the entire bonsai -- plant and soil -- daily. If you skip even 1 day you can permanently damage the plant. Make sure your plants are located where rain can fall on them. However, plants should not remain wet or waterlogged for long periods. 

Fall Care

During this period bonsai must be prepared to endure the approaching cold. Plant growth must be slowed. Water plants less frequently to slow growth, and, when growth slows, reduce applications of fertilizers.

Do not prune or cut any branches after mid-August. Do not use artificial night lighting (incandescent filament lamps) on plants after August 1. To reduce winter dieback of flowering trees and maples make light applications of 0-10-10 fertilizer. 

Winter Care

A major problem in winter is to protect bonsai against low temperatures and drying winds. Bonsai can only be left outdoors in climates where temperatures drop no lower than 28 F degrees. This is not the case throughout most of the United States, so a greenhouse, pit, or coldframe is necessary.

Winter frosts will seldom bother bonsai that are sheltered under the foliage of a spreading tree. Watch out, however, during the frost period for drying soil. 


It is easy to construct a simple coldframe for bonsai. Before the ground is frozen, dig a hole at least 1-1/2 feet in the soil. Make the hole as long and as wide as you need for all your plants. Line the sides of this hole with exterior grade plywood, which extends 6 inches above the surface. Put 4 to 6 inches of gravel in the bottom of the hole, set your plant containers on this gravel, and spread straw around and over them. Put a loose-fitting cover on the frame made of polyethylene sheeting or any similar material.

Be sure the top of your coldframe is strong enough to withstand a heavy load of snow. Ventilate on days when the air temperature is above 40 F degrees to keep the plants cool and dormant.

To purchase a coldframe kit, check your local nurseries or see catalogs of mail-order garden supply houses. 


In the summer, during hot weather when the temperature is over 90 F degrees, water the bonsai plants one or more times a day. If the plants are in an unusually sandy soil, they will require watering three or more times a day.

In early autumn, follow the watering directions for late spring. In late autumn, follow the watering directions for early spring.

In winter, keep the trees in a coldframe and ventilate the plants on one or more sides to keep them dormant. Check for dryness every 2 weeks. Water the plants every second day, or less, as required. Keep in mind that far more bonsai are killed by overwatering than by a lack of water. 


To maintain plant growth use fertilizer to supply nutrients. Maintain the nutrient level in the soil mix throughout active growth with monthly applications of a diluted liquid fertilizer. Apply fertilizer only before and during active growth. For a liquid fertilizer you can use a typical house-plant fertilizer (20-20-20 or its equivalent) diluted to one-quarter strength on the label.


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