THINGS TO DO THIS MONTH
Outdoor: This is it, the busiest month in Bonsai. Once the danger of temperatures in the low twenties or less seems to have passed, it is time to bring your trees out of winter protection and into their summer homes. If anything needs to be done (or set up) for this, it should be done very soon. For trees in mulch beds, be sure that the mulch has thawed to below the pots before lifting the trees out of it. Do not force trees from a frozen mulch bed as significant damage can result. Watering requirements will increase, so be prepared to water on a more frequent basis. Fertilization can begin as soon as new growth is seen. Lower nitrogen types will help maintain smaller foliage sizes. Do not fertilize newly potted trees until about 3 or 4 weeks after the repotting. A transplant solution containing vitamin B can be used on these trees. Remove any wire that may become tight during the spring growing season. Replace wire more loosely, if needed. Wire deciduous trees before the appearance of new foliage. Repot trees as they come out of dormancy. Usually, pines, larches, and spruces are done first, deciduous trees and junipers. Reused pots need a thorough cleaning before the tree is placed in them. Pinch off a portion of each new growth on spruces before it hardens. Candle prune pines if further development is sufficiently developed. Also, pinch back new growth on junipers and deciduous trees. Do not prune spring-flowering (apple, azalea, etc.) and “bleeders” (maple, birch) at this time.
Indoor: Watering needs may increase as light intensity and day length increase. Fertilize as needed. Pinch back overly long growth. Do not move these trees outdoors as yet. Do not report
at this time. Check wires and remove any that may become tight during spring growth. Replace wires as needed.
(from BonsaiHai, April 2010)