Azalea

This page will feature a growing collection of bonsai plant material description and infomation on care and culture.
While originally written for the North Alabama micro-climate in the Tennessee Valley region 
of the southeastern United States, these articles should apply for other medium - high humidity areas in USDA
agricultural zones seven and eight.

Paul Barrett Notes from Kathy Shaner Workshop - 10/16/05

Styling - Azaleas can be trained for either flowers or bonsai but not really for both. Azaleas trained primarily for flowers usually have a shrubby appearance - much like a landscape azalea in a pot. Most often, azalea bonsai are trained in the informal upright, "pine tree" style, though they're suitable for other styles as well. In designing an azalea bonsai, follow the strength that's already there. If there is a choice between two different styles, choose the one that uses the tree's natural features to best advantage.
Wiring - Use heavier wire than you think you need. Too light wire may be easier to put on, but it makes it easier to break branches, it doesn't hold as well, and it's harder to bend branches to the desired shape.
Wire primary branches first. Give movement that echoes the trunk movement, i.e., curves that diminish and get tighter toward the ends of the branches. Secondary branches should start out paralleling the primary branch, then move outward away from it. Learn to use two pairs of pliers to bend wired branches. Use one pair to provide an anchor, use a second pair to bend the wire and, with it, the branch.
The more mass you remove from the bottom of an azalea, the stronger the top becomes. In general, don't worry about branches at the top that are a little larger in diameter than lower branches. Usually, the lower branches will grow fast enough to catch up and get bigger than the upper branches. If you do remove a large branch, particularly at or near the apex, remove only a part of it at a time to encourage back-budding, from which new, smaller branches can be developed.
Azaleas are like a number of other plants used for bonsai in that they have distinct sap lines running along the length of the trunk into specific sections of roots. When a large azalea branch is pruned, it will heal over but the callus will only cover the wound - it will not form a new sap line. So, be very careful about removing large, low branches.

In developing azalea bonsai, follow a three year cycle:

    1.    Allow to flower one year;

    2.    Repot the year after flowering;

    3.    Perform moto bedome the year after repotting.

First Year

Allow azaleas to flower only once every 3 years, but leave new flower buds on through the winter every year. Each flower bud sends a signal to the plant to keep feeding that branch and keep it alive. Removing flower buds prematurely stops that signal. Without the bud, the plant may well give up on that branch and let it die, so any available energy can be redirected to branches with flower buds. Remove flower buds in the spring as soon as they start to swell.

Leave little or no red or dark pink at the top of an azalea bonsai. Remove branches at or near the top if the flowers bloom red or dark pink.

Second Year

In the year for flowering, remove all of the blooms which open first. The first blooms usually are different from the blooms which follow later, and usually are not true to the variety of azalea. For flowering, remove most of the buds, and select the blooms to be kept. Leave about 2 inches between blooms. Water the soil heavily during blooming, but try not to get water on the blooms. Remove blooms as soon as they start to wilt - don't wait for the flowers to drop.
In late February or early March of the year after repotting, perform moto bedome. Strip all or most of the leaves from leggy branches or twigs, and use sharp scissors to cut across the apical flower buds. Leave about ⅛ inch of green at the tip of the branch. This process can be used every 2 years on young, developing trees, but no more often than that - skip at least one year between treatments. The bottom part of the tree can be done without doing the rest of the tree.

Third Year

Repot the same time as deciduous trees - February/March. When repotting, use a sharp knife or scissors to make clean, straight cuts across the bottom and sides. Do not rake or hose out old bonsai soil. If the azalea is a nursery plant, it may need a thorough root cleaning to get rid of the old peat/pine bark soil mix, but otherwise don't disturb the root mass of an azalea bonsai. Exposed roots left hanging out of the root ball will be pressed against the side of the root ball and may well die. New roots don't like to, and often won't grow through the other roots, even fine hair roots. For azaleas that really need more new soil than just around the outside of the root ball (e.g., the old soil has very different moisture retention), use a sharp knife or scissors to cut out wedges at intervals around the root mass. At the next repotting, remove wedges from different sections. Scissors used for cutting roots may be sharpened with almost a 90° angle on the edges. They still can be made sharp, but they'll be less prone to damage from bits of aggregate or other hard material in the soil.
Keep the soil moist after repotting - don't ever let it go dry. Later, after the tree has recovered from repotting, you can encourage root growth by watering less. The tree will send out more roots seeking water. Contrary to some current advice, don't put newly repotted azaleas right back in full sun. Keep them in light shade or at most part sun for the first month after repotting.
Soil - Use more inorganic material than organic. Kathy Shaner uses ¾ kanuma and ¼ sphagnum (sold for use with for orchids). For young trees or trees in need of TLC, you can use a mix of ⅓ sphagnum, ⅓ pine bark, and ⅓ Perlite.
Prepared by:
Paul Barrett
10/16/05

 Satsuki Azalea
Rhododendron indicum

 Satsuki azalea is a cultivar group of azaleas that are native to the mountains of Japan, and are extensively
cultivated by the Japanese, being hybridized there for at least 500 years.  Satsuki azaleas have a diverse range
of flower forms and color patterns with multiple patterns often appearing on a single plant.

Satsuki bloom from May to June; the name “Satsuki” in Japanese is reference to their blooming period, the fifth
month of the Asian lunar calendar. They generally have 1 to 5 inch single flowers, although some have hose-in-hose,
semi-double and fully double flowers.  Satsuki flower shapes range from rounded overlapping lobes to narrow
wide-spaced lobes, with lobe edges ranging from flat to frilled.  Flower colors vary from white to pink, yellowish pink,
red, reddish orange and purple. Color patterns include solids, and stripes, flakes, lines, sectors and margins of color
on a lighter background. The complete range of color patterns can appear on the same plant, differently each year.

Satsuki Azaleas are very popular as bonsai, and many bonsai enthusiasts, and some shows, are dedicated
solely to them.  Satsuki Azaleas can take a hard pruning when needed, the flowers are amazing, and with proper
care they can grow quite fast.

In developing Satsuki azalea bonsai, follow a three year cycle:

Although allowing Satsuki azaleas to flower only once every 3 years, leave new flower buds on through the
winter every year.  Each flower bud sends a signal to the plant to keep feeding that branch and keep it alive.
Removing flower buds prematurely stops that signal.  Without the bud, the plant may well give up on that
branch and let it die, so any available energy can be redirected to branches with flower buds.  Remove flower
buds in the spring as soon as they start to show color.  Leave little or no red or dark pink at the top of an azalea
bonsai.  Remove branches at or near the top if the flowers bloom red or dark pink.

In the year for flowering, remove all of the blooms which open first.  The first blooms usually are different from 
the blooms which follow later, and usually are not true to the variety of azalea.  For flowering, remove most of the
buds, and select the blooms to be kept.  Leave some spacing between blooms.  Water the soil heavily during
blooming, but try not to get water on the blooms.  Remove blooms as soon as they start to wilt - don't wait
for the flowers to drop.

Light:    Satsukis prefer partial to almost full shade. They are understory bushes or shrubs.

Hardiness:     A Satsuki is an outdoor tree.  If left outside over winter, cover with fine pine bark mulch
                     to about one inch above the pot.  During late winter or very early spring, many of the 
older leaves will yellow and fall.  Azaleas are evergreen, but no leaf lasts forever.

Watering:    Water daily throughout the growing season. Satsukis can tolerate some drought, but   
not for an extended period. Water sparingly during winter months
. 
Feeding:    Feed once a month from March through June with a slow-acting organic fertilizer and
then once or twice with a low Nitrogen fertilizer in October or early November.
Feed more often if the soil is inorganic.  Hold off on feeding until one month after repotting.
Satsukis, like most plants, love foliar feeding.  They will love a rotating regimen of diluted beer
(1 Tbs / 40 or 50 oz spray bottle) one week,  HB-101 or super thrive the next week, an application
of Miracid the third week and finally, a spritzing with diluted Hydrogen  peroxide ( 1 Tbs / spray bottle
of water) during  the fourth week.  Foliar feeding is best in the morning when the stomata are open. 
Do not foliar feed after the temperature reaches 70 degrees.   

Styling:    Keep styling minimal during the repotting year.  Wiring may be done at any time, with
the wire remaining on for up to a year. Because the bark on an azalea is very thin, 
for smaller branches it is advised to wrap the wire with a heavy paper first.(paper cut from 
temporary window blinds works very well)  . Wire primary branches first.  Give movement that 
echoes the trunk movement, i.e., curves that diminish and get tighter toward the ends of the branches.  

Secondary branches should start out paralleling the primary branch, then move outward away from it. 
Learn to use two pairs of pliers to bend wired branches.  Use one pair to provide an anchor, use a second 
pair to bend the wire and, with it, the branch.  Check for wire bite starting at 3 months.  If it is not biting,
leave it on but check often.  Prune and pinch carefully at the apex.  Azaleas are not apical, that is, they are 
more likely to sprout new growth from the bottom.  

Do major styling immediately after blooming has finished.  A new growth spurt is about to happen.
Pruning in late summer will reduce next years’ bloom as buds are set in late August.  Removal of all 
foliage on a branch will be the death of that branch, as well as a line on the trunk down to the roots. 

If you wish to encourage significant back-budding and ramification, you can perform moto bedome.
This is done by cutting all flower buds and leaves, leaving just about 1/8” to 3/16” of green on each bud and leaf. 
This can be done the year after repotting.  Azaleas develop veins or water lines wherein some roots feed 
particular branches directly.  When pushing back foliage, be sure to leave some green on the branch.  Thinning
is important as it lets light into the interior of the plant and encourages back-budding.  Always remove spent 
flowers AND the seed pods to conserve the strength of the tree.
Flowering is subjected to the three year schedule.  

Potting:    Repot every 3 years for young trees or every 3 to 5 years for trees over 10 years old.
Repotting is typically done from mid winter through early spring.    Many artists
repot azaleas after blooming but it is ill-advised in the Tennessee Valley due to fierce 
Summers that can begin in late May.   A glazed pot that is not too shallow is preferred.

When repotting, use a sharp knife or scissors to make clean, straight cuts across the bottom and sides.
Do not rake or hose out old bonsai soil.  If the azalea is a nursery plant, it may need a thorough root cleaning to
get rid of the old peat/pine bark soil mix, but otherwise don't disturb the root mass of an azalea bonsai.  

Exposed roots left hanging out of the root ball will be pressed against the side of the root ball and may well die.
New roots don't like to, and often won't grow through the other roots, even fine hair roots.  For azaleas that really
need more new soil than just around the outside of the root ball (e.g., the old soil has very different moisture
retention), use a sharp knife or scissors to cut out wedges at intervals around the root mass.  At the next repotting,
remove wedges from different sections.  Scissors used for cutting roots may be sharpened with almost a 90° angle
on the edges.  They still can be made sharp, but they'll be less prone to damage from bits of aggregate or other 
hard material in the soil.

Keep the soil moist after repotting - don't ever let it go dry.  Later, after the tree has recovered from repotting,
you can encourage root growth by watering less.  The tree will send out more roots seeking water.  Don't put newly
repotted azaleas right back in full sun.  Keep them in light shade or at most part sun for the first month after repotting.

Pests:    The most common pest for azaleas are lacebugs.  These are easily controlled with fine 
horticultural oil, watering with a heavy foliage spray, systemic pest control and thinning
foliage to maintain good airflow and maximize pest spray contact.   Spray with dormant oil in 
January or early February. 

Diseases:    Fungus presents a significant threat in the Tennessee Valley.  From March through June
or July, alternate weekly treatments with a copper fungicide and daconil.  Good 
airflow maintained by thinning foliage is critical to good control.  Spray with a mixture of 1 tablespoon of 
3% Hydrogen Peroxide in a 40 to 50 oz. Spray bottle at least every other week during the Spring.