Tallahassee Bonsai Society

Now that the hectic level of Spring activities is slowing down, it doesn’t mean that you can relax now.  There’s still plenty to do with your bonsai during the Summer months.  Below is a list, though not exhaustive and in no particular order:

• Pruning/pinching – For mature trees, to increase ramification on deciduous trees, in late May,  cut branches back to two sets of leaves after the branch has extended about 8-10 sets of leaves.  Leave the embryonic bud on the side you want the branch to continue growing in, while pinching out the other one. This is also the time for major limb/trunk chops.  For trees in training this is optional, as you want to increase the girth/height of the tree. Let them grow freely unless it is interfering with the final design of the tree.

• Check wires – Check existing wires on all trees as Spring growth may have caused some of them to begin biting into the bark.  Remove wire that is too tight. If branch has not held the desired position, then rewire in a different wiring pattern. This is an excellent time to wire if the tree is being defoliated (see below) as the branch structure can be seen and accessed easier.

• Water – It is best to water from mornng until mid-day if possible during the Summer, in order to cool off the soil and pot, and to ensure that the tree has enough water when it needs it the most. It is not advised to water in the evenings in order to prevent fungal infections.

   – During rainy spells, when pots are continually soaked, treat trees and pots with fungicide.  Some are for above ground (leaves) and others are for below ground (roots) such as ‘Sub-Due’ and ‘Ban-Rot’. Systemics are easier to use.  Pots can also be tilted to allow excess standing water to drain more effectively.

• During dry spells it is good to soak pots in a pan/tub of water occasionally (at least once/month) in order to ensure that all of the soil is getting soaked when watering.

  -Consider buying an automatic watering timer, available at Wal-Mart and garden centers for when you will be away on vacation. They attach to your hose and are programmable to come on and off when  you want.  No more worries about leaving your trees for an extended period of time in fear of them not getting watered. Only use automated systems when you are not available to water your trees yourself.  Different trees have differing watering requirements.

• Azaleas – After your azalea’s blooms begin to fade remove them and make sure that you also pinch off the seed pod.   Don’t water azaleas from overhead when in bloom, for the water can discolor the flowers.  After old blooms are removed, style and repot.

• Shade – Keep understory deciduous trees such as maples, elms, beech, birch, etc. in shade during the Summer months.  Their natural habitat involves being sheltered from the strong rays of the sun.  However, prolonged deep shade will encourage long internodes and weak, spindly branches.

• Fertilizing – Continue your fertilizing schedule until temperatures are constantly about 95* F.  Most trees and plants enter a Summer dormancy at temps. Above 95*.  The tree will not benefit from fertilizer when it is not growing.  When the temp.’s cool again and you begin fertilizing until late Fall. Use a well-balanced fertilizer, preferably organic.   Withhold fertilizer from a weak or diseased tree.

• Cuttings/Air-layering/grafting – Early Summer is the time to strike greenwood cuttings (from current seasons growth). It’s not too late to start semi-hardwood cuttings either.  Dip in Rootone, and plant in moist sand in a shaded area.
• Approach graft and air layer trees from May – June.

• Heat protection for pots – Studies have shown that plant/tree roots begin to die at temps. above 118*F.  ceramic/clay pots in S.GA. during the Summer can surely exceed those temps. if not protected.  Watering in early afternoon helps, as it cools the soil and pot at the hottest time of the day.  However,  studies have shown that even 30 minutes at temp.’s above 118* can kill roots.   That means that the good habit of rotating pots can even be more detrimental if your pots are not protected, because you are exposing even more of the roots to lethal temperatures!  If your  trees spend more than 1hr. in full sun, the best solution is to either erect a shade cloth that will shade the pots for a few hours during the hottest part of the day, or cover each individual ceramic/clay pot with a fabric of some sort that will shade the pot, yet not impede water flow.  I use burlap, which is available at Wal-Mart. It is cut out to fit each pot, then  pinned (bonsai wire shaped like candy cane) onto the pots to keep it from blowing away.  Aluminum foil can also be used. Plastic or mica pots do not need to be protected.

• Preserve dead wood – Reapply lime-sulfur to your jin and shari, to prevent fungus growth. Wood should be moist in order to allow the preservative to penetrate properly.  Consider applying a wood-hardener (Minwax wood hardener available at Home Depot) to any delicate dead wood to prevent rot and breakage. Do not let the lime-sulfur or wood hardener get into the soil. If using both, the lime sulfur must be applied first and allowed to dry before applying the wood hardner.

• Leaf prune (defoliation)– You can leaf-prune most healthy deciduous trees from early to late Summer. (exceptions: do not defoliate red maples {japanese as well}, hornbeam, beech, birch, crabapple, cherry) Trident maples can actually be defoliated twice in a growing season, if healthy. To strengthen weak branches and distribute energy evenly throughout the tree, only partially leaf-prune them (or not at all) while completely leaf-pruning the stronger ones.  The trees will put out a nice shiny set of smaller leaves. Also, this will allow more light into the tree, which may encourage back-budding, and thus more ramification of the entire tree.  This can be performed every other year, but only if the tree is healthy and has been fertilized a few weeks before, and has not been repotted earlier the same year. If you want the branch to elongate, do not cut off the terminal bud. However, for ramification and back-budding, remove the terminal bud of the branch in question.  Keep newly leafed trees out of full sun, and limit water/fertilizer until the new leaves have hardened off. 

• Repot Tropical’s – Now is the time to repot your Tropical trees.  Make sure to keep the roots sprayed with water during the repotting process. Do not ever let roots dry out completely. They can be hard-pruned at the same time.

• Wisteria / willows / bald  cypress– Can be kept in a shallow pan of water in July – August. 

I’m sure that there are many activities that I’ve left out of this list, but at least this list will keep us busy for a while.  Enjoy the fruit of your labor this Summer by enjoying the beautiful little trees that you have created.