SF Bay Area Suggestions 

By Mr. Umehara

April

Early Part of the Month

Transplanting

This is the best time to transplant cryptomeria, needle juniper, citrus
trees, pomegranate, crepemyrtle, and willows. Conifers missed 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 at this
period.  The sun will warm turned pots evenly to stimulate the roots,
and the foliage will receive the light it needs. Spring Fertilization
Wait three weeks before fertilizing any transplanted trees.  After the
first application, then once a month until October.

For fruit/berry-bearing tree, confirm that the fruit or berry buds are
formed and  stabilized before fertilizing.  The first applications
should be a liquid fertilizer, followed by cake fertilizer every two
weeks or monthly intervals.

For maple and other trees that need control of growth of new buds to
maintain the delicate looks of the branch tips, fertilizer application
should start only after the bud nipping  is finished.

Fertilization Application Guidelines

The following table is applicable to trees  that are fertilized once a
month from April to October.

Plant Species        Pot Size        # of Cakes
Black pine,                12 inch          8 - 1-inch cakes
needle junipers
Other conifers,          12 inch           4 - 1-inch cakes
flowering & fruiting trees
Deciduous trees       12 inch           2 - 1-inch cakes

Remove fertilizer cakes when the temperature goes above 90o F.  Satsuki
blooming can be controlled to some degree by transplanting at this time
if a delay in blooming is desired.  Thinning of the flower buds is
necessary if there are too many. Cut back overgrown new shoots and spray
with Benolate to prevent flower blight damage.

Mid Month

Black Pine - Spring Candle Nipping

When the candle reaches its height and the needle buds (like pimples)
appear on the candle, it is time to nip the candle.  First decide on the
height of the apex and nip the candle accordingly.  Even if no more
height was desired, leave a few buds on anyway. On a finished pine in
good health, that has been transplanted in the prior year, NOT THIS YEAR,
the candle can be removed from the base as is done
in the shortening of pine needles.  Within two weeks, the new buds will
develop, and by October, those buds will become new shorter needles.

This method is better for the Bay Area, where the weather is cool and
the regular method of needle shortening does not work that well.  Also,
in this method, the apex height stays the same and induces new buds of
the branches.  Leave the inside branchlets alone.  Eliminate all needle
buds growing downwards.  After 20 days, eliminate all strong buds.

Late Part of the Month

The time to air-layer deciduous trees is as soon as the new leaf is
stabilized.

To attain new flower buds for next year for:
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 on.
2. Crabapple and karin:  Leave 2-3 strong wild branches on to slow
down the growth of the other desired branches that will produce the
flower buds.  In the fall, cut off the wild branches.
3. Bittersweet:  Recognize the berry buds and cut off beyond the next bud.

For Miyame Kirishima and kurume tsutsuji, clean after flowers.  Cut back
and transplant. For Ezo spruce, cryptomeria, needle junipers:  when the
buds grow to about an inch long, pinch back by fingers to about 1/3 the
length.