Serving the Pikes Peak Area since 1987



CARE  INFORMATION,  PART III

This Page Last Updated: October 3, 2011




Outdoor Trees
Indoor Trees
Watering
Fertilizing
Transplanting / Repotting
Soil Mixes
Winterization
Digging Trees in Spring
Mountain-Collecting Criteria
Other



SOIL  MIXES

Coarse for good drainage and oxygen flow for the roots with enough organic matter
to retain the proper amount of moisture for each type of plant and its micro-climate location.

A general-purpose mix would be one part decomposed granite (1/4" minus) or chicken / poultry grit + one part general-purpose potting soil mix; or
three parts chicken grit + two parts potting soil; or
four parts chicken grit + four parts forest mulch + one part peat moss.  For acid-loving plants, switch the last two ingredients to one part mulch + four parts peat moss.

A recommended mix for conifers would be one part Turface® + one part pine bark mulch + one part pea gravel.

Another pine mix is
one part hard Akadama + one part lava + one part pumice, with 5% of the total mix decomposed granite and 5% charcoal, all washed and screened down to 1/4 inch.
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WINTERIZATION

Why?

    To Moderate the Temperature Fluctuations that We Have

1) Low temperatures between -20° and -10° F (USDA Zone 5).

     2) Moisture-withdrawing winds and low humidity.

     3) Temperature fluctuations (sometimes up to 70°F during days) which can bring trees out of dormancy before late winter freezes.


How?

     1) Before mid-August: stop fertilizing, especially with high-Nitrogen products.
(For outdoor plants here, regular fertilization is recommended from early May to early August -- "feed weekly weakly".)

     2) September: start slowly cutting back on watering to help harden the wood.

     3) No heavy pruning after mid-summer, otherwise too much delicate new growth will be stimulated.

     4) Thin any thick foliage masses on junipers to allow more light in during winter, then the new spring buds will be fatter.

     5) Pack outdoor bonsai trees to keep an even temperature. 
Use a non-glazed cold frame/poly frame (can be made with 3/4" galvanized steel and 60+ mil poly plastic), unheated shed or garage, vented greenhouse,  bottom shelf of a sheltered workbench, a non-southern corner of the house protected from the wind, the north or east side under a large and protective landscape tree, and/or bury the bonsai trees still in their pots in the ground.
Then, surround and cover with several inches of some type of mulch (wheat straw, oak leaves, pine needles, bark, snow, foam peanuts, etc.).  (Be aware that in a very small and humid setting, however, spores on the non-oak mulch leaves could multiply into a potential fungal or other infection for your bonsai.)
Be careful your trees do not get too long of direct exposure to sunlight (or snow-reflected sunlight): sun-scald in winter is caused by the heating up of one side of the tree so that the sap rises prematurely during the day and then is frozen at night, sometimes resulting in bark splits.
Once deciduous trees have lost their leaves they can be kept cold and dark.  (As soon as deciduous trees start to bud in late winter/early spring, you will need to put the plants in light -- with temperature protection -- so that the new growth doesn't get too weak and leggy.)  Evergreens probably do not need some type of light during the daytime.

     5) Check regularly and water as needed.  Dehydration can quickly happen.

     6) Pots most likely to break during the winter are either low-fired terra cotta-like or contain wet, muddy soil that expands.  If during winter a bonsai pot is discovered to have broken/split, as long as the roots are not exposed, leave until spring and then re-pot.  If the roots are exposed, tie the pot together and mulch around it extra well.  Pay extra attention to #4 above.

     7) Tropicals brought outside on occasion in the summer need to be kept inside when outdoor nightly temperatures are consistently in the 50s.  Indoor plants need very good LIGHT and good air-circulation.  Be sure they are not too close to the glass of an uninsulated window.  It is recommended to get a small personal-type fan and let it blow across your indoor trees for a few hours two or three times a week to help keep insects at bay.  Feed indoor plants monthly throughout the winter.

     See also this in-depth Freeze Damage article.
 



     ROCKY  MOUNTAIN  WINTER  CARE

     "Since you may not be familiar with winter care of bonsai in this area, I should like to mention a few of my numerous bitter experiences.  Colorado has extremely changeable winter weather.  The sunny daytime temperature of 60° F is very fine; but after sunset the temperature has been known to drop to -0° F to as much as -20° F at midnight.  Under these variations, bonsai in ceramic pots, which are sitting on the ground, cannot take and have not taken the extra severe changes of the winter climate.

     "Some 15 years ago, give or take a few years, I had not known these facts and, regretfully to this day, lost many beautiful bonsai of untold value.  Still reminiscing, what heart-breaking times for many of us bonsai growers!  In spite of or because of this, we've put our heads together in earnest and furthered dedicated research.  There have been numerous conclusions, the most important of which is to understand and follow the natural way of forest or field.

     "1.  Be ready, even as early as September, to winterize bonsai, since it is always 'later than you think.'

     "2.  Bury every bonsai in a pot, to be buried in the ground, up to the rim of the pot in gravel or sand.

     "3.  Why in gravel or sand?  Because either provides excellent drainage.

     "4.  Reason: in freezing weather, ground and pot freeze together; when thawing in mild temperatures, they thaw together.

     "5.  If bonsai are set on top of the ground or atop shelves, there may be freezing, then thawing, which would injure the fine root system inside the pots.

     "6.  Then, with approaching spring, the root system invariably cannot regain activity.

     "7.  To this day, by unsoothed bitter experience in these areas, I have known a cold snap to occur even the first week in September for three or four days.  One must always be on the alert.  Most bonsai must be protected and covered at night with heavy plastic sheets, which are removed in daytime.

     "8.  In freezing weather, just let the bonsai alone; do not water.

     "9.  During a spell of warmer temperatures, apply water.

     "10.  Lastly, though mighty important, based on my own experiences and findings: The first year after planting is not bad, because the root system has not stretched out too far nor become established inside the pot.  In the second year, many roots will have stretched toward the outer circumference of the pot.  In the third and later years, more roots will have encircled within the pot; these are the crucial, dangerous years, if bonsai are not buried in the ground in sand or gravel.  I cannot stress this point too much, for I have suffered losses and hope that you will benefit from my experience and thus be saved some losses."

(George T. Fukuma (1902-1974), Denver, ABS Journal, Fall 1971, pp. 54-55)




     SCHEDULES for the Rocky Mountain & Great Plains Region

Dec - Feb     give bonsai winter protection
Mar - midApr     acclimate trees for spring conditions
midApr - midAug     best time to transplant bonsai
Oct - Nov     acclimate trees for winter conditions

May - Jul     wire and shape deciduous plants
Dec - Mar     wire and shape evergreen plants

(from Jerry Stowell's The Beginner's Guide to American Bonsai, 1986, 1978, Appendix C, pp. 120-121)

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Outdoor Trees
Indoor Trees
Watering
Fertilizing
Transplanting / Repotting
Soil Mixes
Winterization
Digging Trees in Spring
Mountain-Collecting Criteria
Other

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