This is the busiest month for bonsai tasks. You should start bringing your trees out of their winter hibernation. The weather is the determining factor. The deciduous trees are the first to bring out. As you take out the trees, examine each one for old wire. Remove wire if you have inadvertently left some from last year. If you have already started wiring some, make sure it is not too tight. Remember, the branches will swell quickly in the spring; and, if the wire is too tight, you will get scaring, which will take forever to repair.

 

Also examine the trunk for moss growth. You don't want moss growing on the tree. If you do see any, use an old toothbrush and a mild soap solution to gently work it off. Some trees, such as dawn redwood, benefit from a gentle trunk cleaning even if you don't see any moss (it can stimulate new branch development). Also trunk cleaning with a mild detergent can help clear the trunk of any bugs or fungi. While your cleaning the trunk, you should also clean the pot.

Repotting should begin. Deciduous trees are the first to go through this process. When buds begin to swell, it is time. Generally maples are the first to be transplanted, with oaks last. However, bud swelling is the key determining factor, and the microclimate a tree is in will control that.

Evergreens are repotted last. These trees need to be coming out of dormancy before they are repotted because root pruning may cause root rot if the roots are not actively growing. I typically don't bring my evergreens out of their winter mulch until mid to late March - again, depending on the weather.

Newly transplanted trees need to be protected from the direct sun and wind for three to four weeks. They should be kept moist but not wet – this is especially important during our wet springs. If we have extremely wet weather, I put my newly repotted trees in an enclosed porch. This way I can control the amount of moisture the trees get. Watering for non repotted trees should also be watched carefully. Trees coming out of dormancy require different amounts of water, depending on the tree species and the amount of new growth. Use the chopstick method to monitor the need to water the tree.

Never fertilize a newly repotted tree. Wait at least a month before you start using any fertilizer.

March is a month when the temperature fluctuates wildly. Be prepared to protect your trees if the weather turns cold or if there is frost predicted. Frost can kill new leaves, flower buds, and may even damage new root growth.