Maple bonsai can be grown from seed

Press, 7 September 1989, Page 10

Maple bonsai can be grown from seed

By

BERNARD RUMSEY

Of all the deciduous trees that can be trained into bonsai, few surpass the maple for all-round good looks. Its brilliant foliage in the autumn can, depending on the variety, turn to every shade of yellow, orange, red or brown.

Suitable maples are available from nurseries but they' are difficult to find as now the many cultivars available have been grafted on to root stock. In rare cases these grafts can be used in the design of the bonsai, but it takes many years for the graft to figure as a “tanoshii” pleasant effect.

In most cases the scar detracts from the over-all beauty of the tree. So the bonsai grower must look for other sources of supply.

Because of crosspollination, maple seeds do not grow true so there will be some slight differences in the bonsai raised from seed.

Although using seed can take a number of years to produce bonsai, it does have one major advan-

tage; it allows the grower total control over the trees’ development.

There are two commonly used methods for raising seedlings: seed trays or open ground seed beds. Each method has its own benefits. Seed trays may be more convenient, but the seedlings will develop faster in the open ground. Maple seeds require stratifaction and this can be done in the traditional manner by exposing them to the elements. Simply mix the seeds with sharp sand and place the mixture in a container and leave outside over winter.

Be sure that whatever container is used has drainage holes.

Another method of stratifaction is to use the kitchen refrigerator. Using moist sand, mix seed

and sand together and place in an airtight container and keep in the refrigerator for eight weeks. Remove from the refrigerator and soak the seed overnight in water that has had a fungicide added. Good seed will sink to the bottom. Remove seed that floats. Rinse the seed in clean water and sow in seed flats. Cover the seed to a depth of two to three times the diameter of the seed and firm down. Place the flats in a sheltered position and protect from the frost. When seedlings have germinated, in about a month’s time, apply fungicide to prevent damping off.

If you are fortunate enough to have access to maple seedlings that have sprouted in the ground from the parent tree, they should be lifted in the spring when the central bud begins to open. Maple seedlings will not develop

fully near the parent tree, so if the open ground method is to be used, the seedlings will still have to be transplanted. To keep the seedlings from drying out a wet towel can be used or else they can be placed in a bowl of water until potted. Transplant seedlings into individual threequarter planter bags as soon as the central bud begins to open. The tap root is cut off leaving the small side roots.

Begin fertiliser and pesticide schedule 10 days after transplanting, and continue every ten days throughout the growing season for two years. In the spring of the third year the seedlings will have attained a height of approximately eight inches. Prune all roots to the same length. Cut directly across the entire root system, leaving the radiating roots about one inch long. Repot into five inch containers. Be sure that

the roots are spread out evenly and are well covered with mix.

As the tree grows these radiating roots will thicken and will be exposed, creating the buttress of the tree.

Do not remove any foliage or buds. Ten days after potting begin fertilizer schedule during the growing season. Turn pots periodically for even sunshine only when growth has started to develop.

By the spring of the fourth year the plants will have developed individual shapes in the lower trunk. Prune trunks back to one to four inches in height. Allow the uppermost shoots to lengthen. Water and fertilise throughout the growing season. In the fifth year the plants will have two leaders growing opposite

each other from the previous year’s cut. One of these leaders is removed and the other cut back to the shortest internode.

Trim roots and repot. Continue to fertilise.

Unneeded auxiliary growth is retained to thicken the trunk. Keep short internodes and prune the long ones.

Wire the first and back branches. This first branch can be on either side of the tree and will be situated about one third of the total height of the tree. Remove the wire after two or three weeks as maples mark very easily. When you develop bonsai from seed some basic horticulture techniques have to be employed, such as root pruning. Root pruning is one of the secrets of container gardening. It increases the number of feeder roots. The more feeder roots the more food, and the more food the quicker the growth. By allowing the tree to develop long leaders, trunk development in-

creases in diameter. After pruning the new shoot system is much smaller, and this is how the trunk is tapered in relatively short time.

Give lots of water, pruning, and food for the first five years.

In the sixth year the development of the bonsai’s crown begins. Prune the previous year’s growth back to one or two nodes on the trunk and main branches. Rewire branches as before and fertilise.

Seventh year, and once again you prune the previous years’ growth back to one or more nodes on the trunk and main branches.

Transplant into a bonsai pot after root-pruning, and leave in a sheltered position.

Again in the eighth year the previous year’s growth is pruned back to one or two buds. New growth tips are pinched and the styling is continued with scissors.

At about this time leaf reducing can be started. In bonsai leaf reducing techniques are used for two reasons; to reduce the over-all size of the leaf in the crown, thereby creating a better balanced tree and to slow growth so that the internodes are as short as possible. This creates a light, dense twiggy effect which greatly adds to the bonsai’s “Wa.”

The fertilising schedule should, if possible, now be carried out by foliar feeding. If this is not possible, use a low nitrogen fertiliser.

All maples can be trained into bonsai from seed, although some Varieties are easier than others.

The Trident Maple (Acer Buergerianum)’ and the Japanese Maple (Acer Palmatum) and its cultivars are the most popular.

Keep seed in refrigerator for eight weeks

Water, and feed throughout growing season

Some varieties are easier than others