Tree Tips

June 2026

We have our silent auction this month so remember to bring your checkbook or cash or credit card with you, as well as bonsai related items for the auction. This can be a lot of fun and might snag you a great tree or starter. I Love this time of year. It's an opportunity to get new material to work on and develop into bonsai. It's also a great time to pare down some of my trees to make room and free up time to make new bonsai. It may be time for you to put in material you want to pass along and get something you can get excited about in your quest for the perfect bonsai. You can fill out the bidding sheet and donate 20% or more to the club - this is one of the biggest sources the club has to raise $$ for programs and events - so be as generous as you can.

Back to bonsai…

Black pines

For our hot area, decandle healthy black and red pines from now until early July. Larger trees first then shohin in early July. However the foolproof and best time (it’s not so much a time or date as it is a condition) is when the new NEEDLES extend out and away from the candles. Weak candles that have not extended at all leave intact. Short candles on inside and lower part of tree cut at the base. Medium strength candles cut about 1 to 1 ½ times the diameter of the candle above the base of the candle. Strongest, cut about 2 to 2 ½ times the diameter of the candle above the base. And/or cut the short candles one week, the medium candles the following week and the long candles a week after that. This helps give weaker candle area a head start in developing uniform budding. If your needles don’t extend by the end of June, cut them back anyway. You must allow sufficient time to form the new buds to emerge and elongate by winter. Much later and they may not set well.

If this is too complicated for you and you would like to use an alternate method, cut all candles, regardless of size or strength, at the base. Then pluck needles on the strongest areas to equalize the strength of the tree. Since you have been fertilizing heavily to this point, stop fertilizing and don’t resume until late in the summer when new candles are growing. Regardless of the technique you use, you can regulate the growth on the tree by equalizing the needle load.

Fertilize

Fertilize your trees regularly. If you keep your trees healthy throughout the year, they can stand up to the extraordinary work we want to do with them. I have described the use of organic fertilizer each year. This year, I mixed up a concoction of organic fertilizer (Dr. Earth 5-5-5) and composted chicken manure. I mix this DRY, putting an ounce of it in a tea bag. I then dip each teabag in a dilution of fish emulsion before placing two bags on a small tree or four on the corners of a larger tree. Be sure to wear latex gloves or your hands will smell nasty for a while. The nitrogen part will break down in about a month so I add a second set of bags at the 4 week mark etc. through the year. Stretch it to 6 weeks if you are trying to keep a refined tree from growing out of shape. Daily watering breaks it down steadily, and it also adds organic matter to my soil which is almost entirely aggregate. The chicken manure is Jongs Grow Better Organic Fertilizer, a composted and palletized fertilizer from chicken manure chicken. I got it at Regan's Nursery on Decoto Road off 880.

Alternately, or in conjunction with the above, you can also use chemical fertilizer as either the primary or secondary system. Peter Tea has advocated the use of Osmocote every three months as an easy way to deliver what your plants need. In addition, a product like Dr. Earth®, Dyna - Grow® or Miracle Grow® has all the trace elements that the plant needs. I have also used Bayers 2 in 1 Rose food and systemic insecticide product.

Wiring new shoots

For most trees in the developing stage, the initial shoot that has come out this year should be wired. You want to get movement for about the first three buds, or about 2 1/2 inches, that you will let grow and thicken until autumn. Then you will cut back to those three buds. This will set the movement and give you taper when the next years growth comes out and you wire the shoots from these three buds. Following this yearly pattern you will increase the buds to nine the following year (3 x 3) and 27 the next year (3 x 3 x 3). Each year the sections nearest the trunk will get a little thicker than the ones farthest out on the branch and give you increasing ramification and natural taper.

pinching and pruning

This is an important time of the year to keep the growth pinched back or pruned back on refined trees. These are the trees that you want to show this year or are at a highly refined level.

Pinching on refined trees is done with the fleshy pads of the thumb and forefinger, not the nails. It is used to pluck the new succulent growth back to 1 to 3 leaves before it has begun to elongate. By pinching it at this juvenile stage it stops the internodes (space between the leaves) from elongating. If you don’t catch it, the space between these leaves will stretch like a pulled rubber band until the shoot starts to form wood and the elongation process stops. By pinching it, the wood making process begins immediately, thus keeping the internodes compact. The farther out on the tree this is done the more crucial this work is. This is a handy technique to keep shoots from jumping out of the branch silhouette you have established. This is a technique used on trees that are in the refinement stage where you want to slow down the response of the new shoots. Because the tree is pushing out the growth and has not yet started to photosynthesize, i.e., started to get energy back in to the system of the tree, the response is weaker and the new shoots will be shorter, finer and in better scale for the refined exterior of the tree that we want.

Pruning is cutting back with scissors. If you try to pinch a shoot and it is hard to do or leaves a hardened core at the site, wood has formed and you need to use bonsai shears. Sometime the initial growth has gotten so long, i.e., the first leaf is too far out on the shoot, that the entire shoot must be cut back to the base and started over. Otherwise, the ramification will look odd and the effect will look bad. Pruning is also performed to shape the structure of the tree, or to induce back budding.  

air layering

The May and June time-frame is the perfect time to air layer a tree. If you have an interesting top or branch of a tree and what is under it is ugly, you have a candidate for this operation. Determine the angle and front of the proposed new tree on the existing trunk. Draw a line on the trunk and then use a sharp knife to cut the top line all the way around the trunk. Mark another line around the trunk about one trunk diameter below the first line. Then remove all of the bark between the two horizontal cuts making sure to removed all the bark down to the cambium layer and a little into the xylem or newest wood. Treat the bark area just above the upper cut with the rooting hormone Dip n grow®. Then wrap wet sphagnum moss around the trunk 2 inches above and below the exposed, bark-less area and place a piece of Glad Press-n-‘Seal food wrap around the moss. Tie it above and below with wire to hold the sphagnum moss in place against the bark-less area. Put some aluminum foil over the plastic wrap to shade the area from the sun. Water it regularly and check periodically to be sure that the sphagnum moss is damp and to see if any new roots have formed. Rotate the tree weekly to insure uniform root formation around trunk. Don’t remove any branches or foliage during this layering time period. Roots will form faster if the growth is unchecked above the layer. 6 to 8 weeks should do it for most deciduous trees. Conifers take longer before you can separated from the under-tree. 🌳