SEASONAL SUGGESTIONS

No. 74 - March/April- 2002

SPRING-- RENEWAL TIME…. REACTIVATE EVERYTHING!
 

Spring is the time of renewal. It’s time to take stock of your trees, whether in pots or still in training stages. Review their future. It’s time to resume a regular schedule of fertilization since the nutrients in the soil have been leached during the dormant winter months. Bud swelling, the sign of spring awakening, begins to show and repotting time is upon us.

Last month was the time to ready repotting supplies - a well drained soil mix, clean pots, supplies of insecticides and fungicides, etc. etc. Now is time for a repotting schedule-- before the buds really open up. Finish your activity before the leaves begin to show. This timing applies primarily to deciduous and flowering trees. Evergreens and conifers such as junipers, fir, spruce and pines can follow. If the tree has begun to flower or develop fruit delay repotting until after blooming. Until the plants become re-established- water cautiously

It's a good idea to include a small amount of Bone Meal and Ironite in your soil mix¬ture to encourage the development of new fine rootage. There is a differ¬ence of opinion as to the value of including cottonseed meal too early. I believe that this fertilizer is better applied later in March to encourage new green growth. Even if bone meal is a slow starter it does adds nutrient benefit to the plant. Don’t overdo your fertilizing. It’s a common mistake to consider the idea that a little good is better if more is applied. Repotted plants may be fed as soon as signs of new growth are apparent. A suggested standard mix is 75% cottonseed meal / 25% bone meal. Trees may also be given an interim push by using a liquid food like Miracle Gro® between regular monthly feedings.

Winter dormancy is over. Bring your trees out of their winter protection from cold winds. Deciduous trees may show the first signs of bud breaking. Keep an eye on any fast growing branches that quickly create elongated internodes. Light pruning of growing tips is in order to control this situation, however do not do any serious trimming until the new growth has hardened. Maintain the shape of the tree as the branches begin to grow. Twiggy branching will be the benefit of regular pinching. Watch for wire scars that may have developed during the past few months.

As each new shoot develops, determine if it is to play a part in your overall design plan. If you need a longer branch - let it grow. If you need more twiggyness or fullness cut the shoots back to two or three sets of leaves. New shoots develop from the cut areas. Don't allow the tree to spend its energy growing unwanted shoots.

Some transplanting and repotting activities may have begun last month but do most of the traumatic replanting work before the growth develops. As warmer weather arrives the root systems will begin to push new hair roots. Repotting at this time prevents excessive damage to the existing root ball.

Newly potted trees should be shaded from direct sun until new growth begins. By moving your trees into sunny areas you stimulate the growth of foliage. Newly potted trees should be allowed to develop new fine rootage that support new foliage. When new growth is evident it’s time to begin light fertilization. Full sun encourages smaller leaves and shorter internodes.

Early bloomers such as Forsythia, Sasanqua Camellias and Quince develop during the early spring months. After the flowers have faded the tree can be pruned back to restore shape and allow new growth and bud setting. Azaleas can be bare rooted and repotted in March. Be sure to comb out as much of the old soil or growing medium peat without destroying the fine root system. Incorporate as much new coarse azalea soil mix as you can when repotting to develop strong healthy new roots.

Take the opportunity in March to change from training pots or oversized pots to appropriate display pots suitable to the finished bonsai. Determine the best size, shape, color and style to compliment your tree. Showtime is coming!

A bonsai, to be ready for repotting, should be somewhat dry. This makes it easier to remove the root ball from its previous home where it became root bound. When repotting a healthy plant be sure to remove heavy roots that have circled the old pot. If roots are cut back some of the foliage can be trimmed to compensate for the tree's inability to move nutrients to the branches and leaves. Don’t allow exposed roots to dry out. Keep them misted and if possible cover them with a slurry of soil dust as a protective coating.

Plan your repotting activity around the following guidelines.

Very old trees(15 years or more) –- repot every 3 to 6 years Younger trees (5 to 20 years)-- repot every 2 to 4 years
Young tree (less than 5 years) - repot every 1 or 2 years.

In every case the decision to repot should be governed by the health of the tree, the condition of its root mass and its growing conditions.

Recent spring rains have been retained deep into every root ball. This creates a haven for a surge of fungus growth. Treat everything as if it’s already infected. Use an all purpose fungicide. Follow manufacturers directions as to strength.

Topical sprays of Bravo® are an excellent deterrent for pine needle cast infections as well as problems on most other conifers and deciduous material. A common complaint we hear is the difficulty of finding Bravo® in most nursery supply houses. Let me give you it’s chemical name-the active ingredient is ‘Clorothalonil Tetrachoroisophthalonitrile’. Bravo® comes in a 40% active solution however the same ingredient is found in the more readily available product called ‘Daconil®’, usually in a 29% solution. It can therefore be used just as effectively as the strengthened solution.

If root rot is threatening, a recommended sub-soil fungicide is Subdue®. Ask your supplier to get it for you or to recommend a substitute. For your information, the active ingredient (25%) is- ‘Metalaxyl: N-(2,6-dimethylphenyl)-N-(methoxyacetyl) alanine methyl ester. (You really wanted to know this didn’t you?) There are numerous fungicide products on the market. Look for comparable ingredients. Be sure that you de¬termine what they treat-below or above the soil level. Most cannot do both.

In addition to the training and care of bonsai this is an excellent time for air layering. Spring is the time when fast growth takes place. New buds are forming and propagation conditions are at their best. Look around the garden. Look at the training stock or ma¬ture bonsai. Pick a branch division that can create an almost instant bon¬sai miniature. Air layering succeeds on maples, azaleas, liquid ambers, pomegranates and elms.

Here is a basic procedure for a high success rate of air layering.

Early in the growing season cut a round band of bark, 1 1/2 times the di¬ameter of the branch from which the air layer is being taken. Cut deep enough to penetrate the cambium layer and into the heartwood. If any cambium tissue is allowed to remain it will permit the tree to rejoin the channels of nutrient flow and will prevent the formation of new roots at the edge of the cut.

Next, use a twist of strong copper wire to form a circle around the upper lip of the cut area. Pull tightly to strangle the trunk or branch to prevent any nu¬trient flow below this area. Apply powdered Rootone® to the upper lip of the cut. Apply a pad of shredded sphagnum peat moss, saturated with a solution of B-1 or Superthrive® and wrap the entire bulge with plastic. Tie the upper and lower edge of this ball with another twisted wire but allow a small entry area to permit the introduction of water when the roots begin to form. Do’t allow the ball to dry.

Several weeks may elapse before evidence of new roots appear. The time will vary with the variety of tree stock as well as the weather conditions. Inspect frequently. When new roots become clearly visible through the plastic and appear to be strong, choose a cool day to cut the branch off below the ball. Plant the new tree in a well draining soil mix. Be especially careful to prevent damage to the young roots when removing the plastic wrap. Do not disturb or remove the moss. It will, in time, disintegrate into the soil. Keep the leaf growth at a mini¬mum to encourage continued root development as the new tree becomes acclimatized to its new home.

Remember,
• The early bird gets the worm but the second mouse gets the cheese.
• For every action there is an equal and opposite criticism.
• Doesn’t this seem to apply to bonsai? The best way to escape your problem is to solve it.

Marty Mann