SEASONAL SUGGESTIONS
By Marty Mann
May/June - 2001

SUMMER --THE GROWING/MAINTAINING TIME

The ongoing process of snipping new growth, when it hardens, continues into the early months of May and June. This must be done before the more aggressive new growth of summer creates long and undesirable internodes. The constant reshaping and cutting back the growth of all trees encourage delicate side branching and create a softer, overall look. Remember, the object of new growth cut back is to maintain a relationship between the size of the leaves and branches to the overall size of the tree. This process encourages branch thickening and adds an aged look. The best time to do any major branch trimming is when the leaves are small and trimmed. Watch the exposed end cuts. Apply a tree seal, or just old-fashioned Elmer's glue, to larger cuts or carvings.

This training produces the most apparent design results. The technique that makes pinching effective is quite complex. Recognize, that in a normal plant growing cycle a plant that is living in a healthy light environment, creates new stems that usually tend to grow straight up -- where the most light falls. This phenomenon is called apical dominance--meaning the bud at its very top dominates the plant. If nature (or the bonsaiist) removes this bud, a message is conveyed to the plant. Growth in that direction is discouraged. A plant that has been pinched back therefore sprouts new branches up and down the older parts of the stem. Side branches appear when the leader is removed. Growing tips at the apex of a branch produces a hormone called AUXIN and has the effects of keeping new buds from growing. There is, however, another hormone group called KININS that conflict with AUXINS and essentially spur dormant side buds to grow. This lateral growth develops twiggyness and the intricate quality of design that makes a mature bonsai compact, small and bushy.

Eliminate spurts of new branch growth. Cutting back young whips to two or three leaf clusters encourages fine twiggy branching and shorter internodes. Remove opposite branches that tend to form on many species naturally. Avoid bar branches throughout your design. This is not as important in the upper structures.

May's milder weather conditions encourage the population of undesirable insects such as aphids, white flies, spider mites and that nasty scale. Particularly, if you failed to spray the wintering trees with a dormant spray you will have to be attentive to the presence of a new crop of insects. Pay attention to regular applications of insecticides such as MalathionÒ, SevinÒ, IsotexÒ, etc. Maples are particularly susceptible to fungus diseases such as mildew when kept in to much shade. Apply general-purpose fungicides such as CaptanÒ, BravoÒ or DonocilÒ at this time to ward off early summer damage. Avoid watering the foliage and allow air circulation and good light exposure.

You may wish to try some of the recommended non-toxic homemade insecticides that combine a tablespoon of dishwasher detergent or mild soap with a half-cup of cooking oil as a concentrate. Dilute this mixture with six ounces of water and spray it on the bark and foliage every two weeks. The detergent emulsifies the oil and spreads it lightly on plant surfaces to smother and kill chewing and sucking insects.

If Pine grooming is taking place in May then care in removal of candles and needles is important. The techniques shown by Japanese masters suggested pruning pine branches by forming clusters of 6 to 10 needles at the end of each branch. New buds and needles are created on old wood--the forming new side branching. Pine buds customarily grow around the sheath covers surrounding needle clusters. Take care not to damage these sheaths.

Watering instruction, relating to the care of Bonsai, is a rather imprecise art. So much depends on whether trees are kept in an environment of sheltered or windy areas. Other conditions, such as humidity or dryness of the surrounding air also affect the health of the tree. The size of the pot and the kind of soil mixture are also factors in the drying out process. Individual trees may react differently under varied sun and light conditions. The best advice, as a sort of rule of thumb, is to water until the excess drains out of the pot. Watch the soil. The object is to keep the plants only 'damp', not 'wet' and never 'dry'. As the weather warms up the watering, requirements must increase, as well as your watchfulness. Keep watering down to a minimum--just enough to keep moisture in the root ball full of fine root hairs. The single most common factor that kills many trees is the tendency to over water. Deep watering accumulates in a soil that may not drain well. This condition causes root rot. Your finger in the soil is still the best test instrument.

With the renewal of active growth, pay attention to those ugly predators, insects and fungus. Aphids multiply actively in warm weather. Fruit flies are attracted to the new young growth as the sugary sap flows. Continue a program of constant attention by the application of good commercial insecticides and fungicides. Check the underside of leafy trees -- a favorite hiding place for insect eggs and larvae's growth. When spraying, be sure to cover the upper and lower surfaces as well as the woody branches and trunk areas. While regularly scheduled spraying is the usual recommendation, it should be noted that too strong a chemical mixture could often do more harm than good. Don't overdo. Emphasis is always on bugs and spores but attention must be given to the accumulation of 'trash' in pots and in growing containers. Keep all plant surfaces clean to discourage the harboring of unwanted tenants. Keep pulling those aggressive weeds that seem to find a home in well-fed plants in containers. Get them out before they become too much a part of your root ball.

Review all deciduous material now, whether potted or in training. Plan leaf defoliation later in June. Leaf pruning improves leaf size and ramification (that's a fancy word for twigging and bushiness). Remember, leaves are ‘food factories’ that produce the sugar that promotes trunk and branch diameters and liqnification (hardening). Leaf pruning works well on Trident Maple, Japanese Maple, Liquid Amber and Hornbean. Some varieties, such as Beech, should not be defoliated since they do not readily develop new secondary leaves.

Pay attention to the azaleas. March or April was the best months to repot and trim last year’s spring whips and branches. May is the blooming season for most bonsai varieties (remember-Satsuki means 5th month) you may enjoy the flowers without any concern for feeding and trimming. Keep the plants moist but avoid overhead watering as this causes the blooms to quickly lose their color and vigor. Cut back any shoots that have outgrown the design perimeters. After flowers have reached their peak, remove all faded blooms. A flat cut at the base of the flower will remove excessive stem elongation and allow new flower buds to form during the summer.

Keep all trees evenly exposed to the warming rays of sunshine and stronger light. Develop a habit of turning each tree on the bench frequently. Be particularly watchful of trees that are backed by a light wall or fence. Strong light reflection induces excess back growth or, in certain conditions, will burn this growth due to reflected heat. Be watchful. Consider the light conditions of each tree. Keeping material in a sheltered or shaded area produces lanky and weak growth. Protect deciduous trees from burning if the weather becomes unusually warm.  Conifers and junipers thrive in a well-lighted area and produce firmer, greener foliage. Remember to compensate for the benefits of good light condition by adjusting your watering schedules.

Growing time is also feeding time for all varieties of bonsai. Feed everything on a regular weekly or monthly schedule. The usual recommended fertilizers should be high in phosphorus and phosphates, such as a 5-10-10 or 5-15-15 formula. Nitrogen, the first ingredient, should be approximately 1/2 to 1/3 of the phosphorous. Feed a tree at least two weeks before doing any serious cut back or leaf pruning. Use a low nitrogen formula in order to restrain any spurts of fast growth.

Check your root over rock plantings from last year. It may be time to remove most of the wire and starts brushing away some of the muck and moss to expose the trunk and roots. The surfaces of the roots should be taking on the texture and color of the bark of the tree.

Take new cuttings of deciduous trees during this period of vigorous growth. Dip the damp cuttings into a powered rooting hormone. Insert cuttings into pure sand or perlite to insure a well-drained mix. Keep the mix moist and out of direct sunlight until signs of new growth appear.

Don’t let the healthy growth mislead you. A tree requires constant care and training. Bonsai is a living art form. These months are the best of times for the green growing activities. Enjoy them and live with them--they are really for your pleasure.