Tree Tips

May 2024

Just got done with the Cherry Blossom Festival. What a blast! I got a ton of work done on my boxwoods and talked to a lot of interested potential bonsai enthusiasts. Hope they can make it to our meeting on Thursday.

Watering and Shade Cloth

The days are longer and warmer, and the sun angle has been sneaking up on us, so we need to get into watering mode now, in earnest, as the growing season is in full swing. My shade cloth is up and operating!

Wiring and Ramification

May is a big time in bonsai. For all except the refined trees, we want to wire the first few inches of the new shoots once they have hardened off. This is the area that we will cut back to in the fall. This is the beginning or continuation of ramification for the branches and will pay big dividends later on if we do the work now. Don't cut back and pinch these shoots now. The exception is if the longest shoots reach out past where you want, pinch the terminal shoot but not the inside shoots behind it. We need those to fill our branch with secondary and tertiary branches and twigs. This will help to thicken and set the movement of the branch.

Watch the wire so it doesn't cut in. You may need to remove the wire and rewire with a larger size to keep the shape. If you didn't cut back to where you need the branch to start, do so now and then, when a new shoot appears and then hardens, wire it and follow the above procedure.

Shaping Established Trees

On trees that have the shape you want, let the shoot extend to four or five leaves and then cut back to two. Or when there are shoots extended, cut back beyond the beginning of the shoot and into the woody branch, and wire any new shoots that pop from there into the new branch tips. Many times we need to do this to get the taper back under control.

Thickening Trunks and Branches

On developing trees that need thickening of trunk or branches, loosely wire and shape the beginning of the branch and let the tips run wild. This should give you a section of branch that you can cut back later that will have shape and girth. But watch out for the wire digging in. It may only take a matter of a few weeks while it sets.

Specific Care for Different Tree Types

Black pine: Don't worry about overly long candles. We will cut the candles from the end of this month through June, depending on when the needles come about half an inch out and pull away from their sheaths. Feed up to the time you candle cut.

White pine: Pinch off all but four sets of needles on succulent, healthy candles and none on weaker ones. We will not be cutting the candles entirely off as in black pines.

Spruces, cedars, redwoods, and the like: Pinch off 2/3 of the succulent new shoot as it emerges with the fleshy parts of your fingertips (not the nails).

Azaleas: If you wish to enjoy the flowers, wait until about 3/4 of the blooms have finished before stripping all the buds off and cutting back to two shoots and two leaves.

Pinching Shoots and Internode Length

I have noticed that sometimes on the same branch, there are shoots with short internodes and some with longer internodes. Sometimes the shorter ones don't extend out. If they don't extend, don't bother to pinch them. But if they are elongating, do pinch them short. Shoots are elastic. The buds contain all of the new leaves when they first push out, but as they grow out into a shoot, the internodal distances between the leaves stretch out like a rubber band. Before the internodes get too long, you can pinch them. This will stop the elongation process and start the hardening process of lignification (wood formation). After they have elongated, they form wood and can no longer be pinched and must be cut with scissors.

Pest and Weed Control

This is a crucial time for pest and weed control, so be prepared to battle everything from aphids to snails, dandelions to oxalis. Spray and bait to tackle these critters. I would suggest using a product with Merit (imidacloprid), such as Bayer's 12 Month Tree and Shrub or Bayer's Merit 0.5g granular insecticide. While pinching, examine your trees for any signs of stress, disease, or insects. Remember to check the underside of the leaves, as many sneaky pests hide there. Mealybugs, spider mites, moths, and beetles—just a few bugs can wreak havoc and ruin foliage before you realize it. Scale, aphids, beetles, and others are best dealt with now before they burrow and sap your tree of its vitality.

Watering and Fertilizing

When watering, spray from the bottom and all around the tree to wash away as many pests as possible. Remove any stubborn ones by hand. If you still notice signs of their presence, spray with a solution of Malathion®.

For healthy trees in pots, continuously fertilize with organic fertilizers like Dr. Earth 5-5-5, with an intermittent application of Dyna-Gro, Miracle-Gro, or another water-soluble, full-spectrum fertilizer. 🌳