Mugo Pine

This pine is a small tree or shrub from Alpine Europe. The dark green, stiff needles grow in pairs, 1-1½ inches long. According to Simon & Schuster's, there are many subspecies of Mugo Pine, because the tree tends to hybridize in the wild. This tree is quite popular as a bonsai subject.

Repotting In early spring or late summer, every 2-3 years for young specimens and every 3-5 years for older ones. Pines need deep, well drained soil, so plant in a fairly deep container. Simon & Schuster's recommends 50% soil and 50% coarse sand. Rémy Samson recommends 1 part leaf mould, 1 part loam, and 1 part coarse sand. Peter Chan recommends 1 part loam, 1 part peat, and 3 parts coarse sand. See comments on soils as well.

Pines and other conifers grow in association with a symbiotic fungus which grows in the root ball of the tree. If this fungus is not present, the tree may die. For this reason, pines and other conifers should never be bare-rooted, unless steps are taken to re-introduce the fungus to the repotted plant, such as making a slurry (thin mud) of the old soil and pouring it over the newly potted soil.

Some experts feel that it is more important to be sure that the tree always has a healthy root system with sufficient feeder roots than to worry about symbiotic fungi. They feel that trees are more likely to die from having their root systems reduced too much at once than from not having the fungus present. Certainly it is good advice in any case to be sure the tree has sufficient roots.

Pruning and wiring Initial pruning should be carried out at the same time as repotting. When repotting, be sure to leave a good root system. Subsequent pruning can be carried out when wiring in the fall. Pinch by shortening new shoots (candles) by two thirds in the spring, before the needles open. Pinch the candles in two stages, pinching the most vigorous candles first and a week later pinching the weaker candles. In the fall, reduce the number of buds on each branch to two to encourage ramification. Also in the fall, thin the needles by removing any needles that are too long or that are growing downward. Thin more at the apex of the tree and less as you work down the tree. This will allow light to reach the lower branches and will slow the growth of the apex.

Wiring should be done in late fall or early winter, and the wire removed 6-8 months later at most.

Feeding Simon & Schuster's recommends feeding once a month in spring and autumn using a slow-acting organic fertilizer.

If you prefer to feed using chemical fertilizers, feed the tree once every two weeks with a half-strength solution of a fertilizer meant for acid-loving plants, such as Miracid. Suspend feeding for two months during the hot part of summer (July and August in the northern hemisphere).

Do not feed if the tree is ailing or has been repotted recently (2-4 weeks).

Notes Spray the foliage with water daily during the summer. With healthy trees, it is possible to remove all the new candles every other year, before they harden. The following fall, buds will appear where the candles were removed. This serves to shorten the internodes and encourage more dense foliage. Turn the tree from time to time so that all parts of the foliage receive adequate light.