Based on San Francisco Bay Area Climate

by Mitsuo Umehara

Early April

  1. Transplanting: Transplanting time that started in late February is still applicable.
    1. Now is the best time to transplant cryptomeria, needle juniper, citrus trees, pomegranate, crepe myrtle and willows.
    2. Conifers: Missed transplanting in March? It can be done in April after the bud nipping. In March, all the transplanted trees were immediately placed in direct sun. However, in April, sudden rises in the temperature and unforeseeable strong wind occurs. Trees transplanted now need protection for a week or so before they are exposed to the full sun. Also, it makes a difference in the growth of trees to have the pots turned around once a week as this period. The sun will warm turned pots evenly to stimulate the roots, and the foliage will receive the light it needs.
  2. Spring Fertilization:
    1. Wait three weeks before fertilizing any transplanted trees. After the first application reply once a month until October.
      Also see Fertilizer Basics.
    2. Fruit/berry bearing trees – Confirm fruit or berry buds are formed and stabilized before fertilizing.
    3. Maple and other trees that need control of growth of new buds to maintain the delicate looks of branch tips, fertilizer application should start only after the bud nipping is finished.
    4. Remove fertilizer when temp > 90 degrees F.


  1. Black Pine – Spring candle nipping is done when the needles on the new candle are open and spread. Usually done in May or June, but if the previous winter was warmer than usual some pines will be ready to cut back in April. See Black Pine Basics


  1. Air-layering: The time to air-layer the deciduous trees is as soon as the new leaf is stabilized
  2. Attaining new flower buds for next year:
    1. Ume – Cut back leaving 3-4 leaf buds on each branch. Let the secondary buds grow until you are certain the new flower buds are one.
    2. Crabapple, Chinese quince – Leave 2-3 strong wild branches on to slow down the growth of the other desired branches which will produce the flower buds. In the fall, cut off the wild branches.
    3. Bittersweet – Recognize the berry buds, cut off beyond the next bud
    4. Miyama kirishima ‘Kakuo’ azalea, Japanese kurume tsutsuji (Rhododendron obtusum) – Clean after flowering. Cut back and transplant.
    5. Ezo Spruce, cryptomeria and needle juniper – When the buds grow to about an inch long, pinch back by fingers to about 1/3 the length.
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