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Monthly Tasks – August

Based on San Francisco Bay Area Climate

by Mitsuo Umehara

Early August

Red Spider Mites (from redspidermites.net)
Red Spider Mites (from redspidermites.net)
  1. Summer watering – temperatures over 85 degrees
    1. Deciduous trees, berry trees such as akebia, karin, crabapple, citrus trees, bittersweet, persimmon, etc., should be watered as many times as needed or move them to a shady area. Don’t allow them to dry out.
    2. Any bonsai for which the trunk base is raised higher than the pot’s edge, or the bonsai is root bound, soak in water first. When the soil is softened, spike several deep holes with a chopstick or a pick and pour in some sand. This will improve water penetration.
    3. Willows, tamarix, and other water-loving trees can be placed in a shallow tray filled with water.
  2. Pest Control – With hot weather, red spider mites often invade and ruin the color of pines and shimpaku. Spray with Ultrafine oil. Remember to move sprayed trees to a shaded area for a week to avoid damaging the tree. Repeat two or three times at ten-day intervals, as the eggs will keep hatching.
  3. Conifers – Daily evening – mist-spraying the leaves will prevent damage from the red spider mites.


  1. Midsummer cuttings
    1. At this time of the year, the pot with the cuttings should be placed in a shallow tray with water.
    2. Materials suitable for midsummer cuttings are quince, cotoneaster, and Ume.
    3. Make cuttings from matured branches of this year’s growth.
    4. Put a layer of coarse decomposed granite in the bottom of a small pot. The height of the decomposed granite should be at an equal height to the water level of the shallow tray.
    5. Fill the rest of the pot with regular sand and proceed with cuttings. Place in the water tray and put in full sun. They will root in a short time.


  1. Beech
    1. A characteristic of the beech is that new buds for the next year will form only on the last two to three leaves at the tip, which creates an elongated branchlet.
    2. The way to control this is to start cutting the branchlet back in the latter part of August. Start with the weak ones first and finish the cut back by early September. Cut back to the last two to three leaves on each branch, cut those leaves off leaving 1/12th to 1/10th inches attached to the branches.
    3. Leaf buds will form at the base of cut leaves. Also, cutting will induce new buds on last year’s branches and stimulate inner branchlets to grow as the sunlight penetrates through.
  2. Cork bark Japanese black pine – this year’s growth can be cut back during the latter part of August through early September. New buds will form immediately, but will not grow until next year. Pull some old needles from the tip and clean up.
  3. Grass – An assorted group planting of grass materials can be made at this time. Select what’s in season and put them together. Have fun!
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