The December meeting had a better turnout then expected due to the holidays.
Greg has been down with a cold, so I am writing his column for this month.
I am very excited to have David Toyoshima speak on Cattleya’s. Also to hear about Stewart’s Orchids, which many of us never were able to visit.
Winter is here, hoping all your outside orchids are not freezing. It has gotten very cold in Pasadena. I would like to wish each of you a Happy New Year!
Leaftip Burn - AOS
I’ve noticed the tips of the leaves of some of my orchids are brown, and guessed it was due to over-fertilizing. This morning, I discovered two small (not tiny) brown spots on a dendrobium leaf. The cane has at least seven to eight leaves, and the spotted one is top-most. By looking at the back of the leaf, I found the center of the brown spots became thinner than the leaf. Are the spots an indication of sunburn or fungus? I have the orchid at an east window, so it shouldn’t be receiving too much sun. — Elizabeth Hsu
The leaf-tip burn you
describe is not unusual in orchids grown in the home or under very
dry conditions, nor is it necessarily indicative of
over-fertilizing, but rather of salt-related damage. This occurs
when the salt concentration in the soil solution reaches a certain
critical point, either through accumulation by over-dry conditions,
or by the excess application of fertilizer. Keeping the plants more
evenly moist, and flushing thoroughly with clean water can also help
to reduce this sort of injury to orchids. I doubt that the symptom
you describe on the top leaf is fungus, and even if it is, it sounds
like a type that is the result of a secondary infection that is
rarely more than a cosmetic problem. Unusually cold water can bruise
the softer tissue of a developing leaf, making it susceptible to
infection in the same way that a cut on your hand is liable to be
infected. The infection usually stops on its own, leaving the type
of lesion you describe. — Ned Nash
Epsom Salts - AOS
I have recently learned that
Epsom salts work well for getting phalaenopsis to bloom. My
You will not read much on this topic in regard to
orchids for there has been little research done. As so often is the
case, the myths and misinformation get spread widely, often by
people selling something. However, this much is true: Magnesium is
an essential element in orchid nutrition. In Europe, fertilizer
formulas are often expressed as N-P-K-Mg, indicating that it is
considered as a macroelement rather than a micronutrient. It can be
made available to orchids in many forms. Potting mixes will often
contain dolomitic lime for a slow-release source. Growers either
top-dress with magnesium sulphate in the spring or they apply it
dissolved in water in the autumn as a stand-alone application at
1tbs per gallon. Sophisticated growers will usually add magnesium in
a chelated form to their liquid-fertilizer solutions. Plant need can
be gauged by tissue analysis but this is probably more complex than
most hobby growers can be bothered with.
Monthly Ribbon Judging
You may have a new plant (less than
6 months) that has produced beautiful blooms that you would like to
share with the other SGVOH members. You may bring it and
display it on our NEW ARRIVALS table. It will not be
judged, but you will receive a raffle ticket.
Our members work very hard watering, fertilizing, and making sure their plants are bug free so we can view them at each meeting. Please do not touch or rub the plant leaves or flowers. Be courteous, treat other peoples plants like you would like them to treat yours.
Members may purchase a personally
engraved SGVOH name badge for $15.00 each.
Members wearing their name tag at our regular meeting can obtain a special ticket for that evening’s Plant Opportunity Table.
•Divide or Repot?
•Keikis & Air Roots
•Potting a Keiki
•Recognizing Mite Damage
•Recognizing Virus Symptoms, part 1
•Removing a Damaged Leaf
•Removing a Keiki
•Repotting a Cattleya
•Repotting a Healthy Orchid
•Repotting an Unhealthy Orchid
•Selecting an Orchid
•When to Repot?