The last month of the calendar winter. The weather is similar to January. The nights will still be below freezing. Toward the end of the month, there are some warm, balmy, spring days. Close the cold frame or the trees get too warm and start budding. The average high for the month is 52 degrees; average low is 27 degrees. The record high is 75 degrees and record low -6 degrees. Relative humidity around 48%.
Watering: As in January, DO NOT allow the bonsai to dry out. Dormant trees in a cold frame do not use much water. Every ten days to two weeks should be enough, but check every week to be sure. Water trees planted in the ground once a week to ten days when the dirt has thawed, usually around noon. DO NOT water frozen bonsai. Toward end of month on warm days the planted trees may need more frequent watering.
Fertilizing: Once during the month add small amount of MirAcid to the water again and a weak solution (2 recommended) of 5-50-17 fertilizer. No nitrogen yet.
Spraying: Not necessary.
Repotting: At end of month, the warm weather may have started the Japanese Maples and other deciduous trees to swell before budding. If they need repotting this year, do it before the buds open. Put them back in the cold frame after repotting. Prepare soil mixtures for repotting the next two months. If you use any garden dirt, bake it at 150N for 1 hour to kill snail eggs, pill bugs, and weed seeds. Soil mixtures may be found in Naka’s Bonsai Techniques I. Add a bit more peat moss to hold water in our drier climate.