Halide-type high intensity lights provide a complete spectrum, and
can be used exclusively indoors. Sodium-type are often used to
supplement natural light. New fixtures with a lens do not produce
significant heat, and the lens protects the bulb from stray
moisture. The 400-watt size consumes about as much electricity as
a 25-in color TV, and plugs into any ordinary home outlet.
AOS Bulletin, 6/92:600 Two very good articles in 11/93
Bulletin (p. 1154 ff.).
Many tropical orchids come from near the equator, and thus have around 12 hours of light available to them in their natural environment. They may have difficulty adjusting to longer/shorter periods. Indeed, orchids require periods of darkness in order to absorb nutrients. Studies at the University of Calgary have concluded that photoperiods in excess of 12 hours are counter-productive. Orchids, March 2000, p 256
However, there is no consensus on the Orchid Guide Digest that this is necessarily true. Tom Hillson (email@example.com), did an experiment where he showed that 18 hours of light produced the best results.
Carl Gustafson (Carl.Gustafson@cbis.ece.drexel.edu) uses this
technique for deflasking, which came from Gerardus Staal (Palo
Alto). Take out of flask. Soak in Natriphene solution for 15-20
minutes, pot in wet spaghnum that has been soaked in Physan. Put
in zip lock bags for 6 weeks to 6 months. Orchid List Digest
After taking the plantlets from the flask, Wells soaks them for an hour to a day in the following solution: mix 1/2 tsp. Truban, 10 drops of Superthrive, and 1/2 cup sugar in 1 gallon of warm water. The plants are then rinsed and planted.
Fertilizers in Reverse Osmosis Water
Nitrogen. It is important to use the correct type of nitrogen. Urea is one type, but it is a slow-release type that should be avoided. Nitrogen should come primarily from nitrates (nitrate salts), with 25% or less from ammonium. Zuma Canyon and Dyna-Grow are two examples of fertilizers using the correct type of nitrogen. Orchid Hunter 8/91 Most useful to plants when new growth is nearing completion (Rentoul, Specialist Orchid Grower, 179 ) Miracid was originally developed as an orchid food.
Manure tea can be made with about 2 cups of composted manure in a bag suspended in about 20 gal. of water. This is a good source of nitrogen.
Suspend hanging plants from a pipe frame rather than the roof
itself. Rentoul, Specialist Orchid Grower, 10
Propane. Can use a Mr. Heater model ( see 3/91 AOS Bulletin
). Propane gauge should be used to detect problems (about
$20). Propane must be stored outside away from sun (20# tank) on
a flat surface. AOS Bulletin 8/91
After using it, place plant in total darkness for 7-10 days to
initiate keikis rather than more blooms. Orchid List Digest
To remove mineral deposits from leaves, wash gently with a cloth dipped in a slightly acidic solution (vinegar or lemon juice mixed with water--about 1 T/gal). May require more than one "treatment." AOS Bulletin 6/93: 633
The following was recommended in the AOS Bulletin, 10/93, p. 1047: SunSpray Ultrafine Spray Oil--2 Tablespoons/gal. as a drench plants every 3 weeks.
Place in clay pots with the mount not touching the bottom, and
place pot in saucer of water (for more humidity). Orchid List
Digest Cedar fence boards can be used (especially for
equitants and even phals). Good woods--persimmon (very good),
plum, cherry, lemon, cork excellent, hapo good, tree fern poor.
Orchid List Digest . In the AOS Bulletin (67:7:687), Anita Aldrich
suggested placing mounted plants into a clay pot for more humidity. If that is not humid enough,
then fill pot with coarse medium, moving to a finder medium as needed.
In repotting some genera it may be helpful to reuse a bit of the
old top moss in order to transfer some of the beneficial fungus to
the new plant. This can also be accomplished by removing a live
root tip or two from a live plant of the genus, crushing on a
saucer, mixing with cooled water which has been boiled, and placed
on the potting mix. Rentoul, Specialist Orchid Grower, 157
Alcohol . 70% isopropyl (or witch hazel as a
gentler alternative) can be used for mealybugs, whiteflies, scale,
fungus gnats, thrips and red spider mites. A series of spays
several days apart may be needed. Alcohol can damage plants, and
do not use near any fire . Can be combined with
insecticidal soaps, but not with oil. AOS Bulletin 7/90
Cloud Cover . Mix one part of this or other anti-transpirant to two parts of water to control mites, scale and aphids. (Bulletin 8/91) Mites can be controlled with 8:1 mix, scale may need repeated sprayings at 2:1. AOS Bulletin 4/92:370
"Dormant" oils. Safer and SunSpray have developed "SunSpray Ultra-Fine Spray Oil," approved for flowering and foliage plants for use during growing season. Call 1-800-745- 7476 for more information. Can be used in combination with either soaps or other insecticides (with concentrations diluted). Care must be used when combining with synthetic organics, because the oil allows for a much easier skin absorption. Do not mix with fungicides, or even spray plants with both in the same 2-week period. Also do not mix with alcohol. AOS Bulletin 7/90 Mix 2 Tablespoons per gal. and drench plants every 3 weeks, applying early on a sunny day the day after watering (ok for seedlings and adults) AOS Bulletin 10/93, p. 1047
Flea collars . Put plants in plastic bags with flea collars. Orchid List Digest
Mix. 1/3 Shultz's Insecticidal Spray, 1/3 70% isopropyl, 1/3 water with a Tbsp. of Ivory soap or insecticidal soap is one possible mix. Mavrik, a synthetic pyrethroid, is a new product that might be worth trying. AOS Bulletin 7/90
Soaps. Ivory Liquid (1 tsp. per quart) is almost as effective as insecticidal soaps, but there may be greater risk of damage. These are much more effective in soft water. Use of soaps can also increase effectiveness of other insecticides, allowing for cutting concentration up to 75% (do not combine with rotenone). Can also be used with "dormant" oils or alcohol (see above). AOS Bulletin 7/90
Systemic. Monthly spray (4), June through September of Orthene Wettable Powder Orchid Advocate 11/92, 221 . Can also be sprinkled on the surface of the planting medium, where it will be absorbed through the roots. Orchid List Digest
Knox-Out. This may be a useful form of diazanon. Duane McDowell
Thomas Sheehan's homemade bug spray. 2.5 Tablespoons mild soap/detergent mixed with 2.5 Tablespoons vegetable oil/gallon. Contact kill. Orchid List Digest
Enstar. For white fly, aphids, scale, mealy bugs. It is a growth regulator which kills eggs and prevents insect maturation. Slow-action. Apply when cool; may need to repeat. Use spreader-sticker (silicon best). Water 24 hours before application. Can't be used outside. No mammalian toxicity. Orchid List Digest
Aspirin. To help control orchid "rots," dissolve 1 tablet of aspirin in 1 liter of water, drain off liquid, and mix at a 1:10 ratio dilution in water, spray on plants. Orchid List Digest
Fungus gnats. Physan added to the water to kill them (reduces the surface tension of the water). Can also be used to drain phal crown to prevent rot in a cool greenhouse. Aqua-Grow can be used as a non-ionic wetting agent to help prevent insects (particularly in winter). Gnats can damage orchid roots. BT, var. israelensis (Gnatrol) can be used as a drench.
Another method of controlling pests like fungus gnats is to place yellow butter/margarine containers around the plants filled with water and a small amount of surficant (Physan will do). The insects fly in and drown. Orchid List Digest
Orchid pollen can be stored (possibly for long periods) in the refrigerator in glassine envelopes such as those used by philatelists. Sources are Freeway Supplies or Subway Stamp Shop. Top
NZ Sphagnum. AOS Bulletin (9/91)
recommends using NZ sphagnum for phals (vandas also?). Problem is
too much moisture, especially roots just below the crown. Use foam
"peanuts" in bottom, and layer in NZ and "peanuts" (about 3/4 inch
layers). Top layer is NZ. Place "peanuts" just under crown of
plant. Use large "peanuts", and loosen NZ occasionally. Use clay
pots, or weight down plastic ones. May also be able to simply mix
peanuts and NZ. Cover surface with charcoal and/or gravel
(prevents algae from forming) AOS Bulletin 110/93, p. 1156
Double potting. Normal potting mix in clay interior pot, inserted into a larger outer pot, with a few strands of spaghnum in the bottom of the outer pot. Preserves moistness and humidity around plant. Can also "water" outer pot during plant dormancy. Rentoul, Specialist Orchid Grower, 182
Recycle plastic pots by soaking in RD-20/Physan solution. Heat sterilize clay pots at 350 for 1-2 hours. AOS Bulletin 5/92
Perlite. This can be used in a reservoir- type pot to take advantage of its ability to absorb water by capillary action, yet maintain aeration. This would be especially useful for odontoglossums and their hybrids. Phals and Paphs may also do fine. Use dedusted horticultural grade perlite. Dedust it by pouring about 1/3 of a bag into a garbage container half full of water/fertilizer solution. The dust goes to the bottom. Wet perlite is easiest to use. Be sure there is 4 to 5 inches of perlite above the water level. May wish to cover surface with small pea gravel. Plant somewhat deeper than you would in other media. AOS Bulletin 6/92:582 ff.
Another version of this kind of growing technique was given on the OGD listserv (Ray Barkalow of First Ray's Orchids). It is semi-hydroponic. The mix used is 50% coarse perlite (70% for paphs) and the remainder coarse charcoal in a closed bottom pot with a hole 1.5" from the bottom of the pot (on the side). It is then filled with water and allowed to drain and somewhat dry out (weekly watering).
Tall narrow pots can be purchased from TO Plastics (Chicago Floral), SVD 2.5; SVD 32 tray. Duane McDowell
For paphs, mix the following: fine grade Sequoia fir bark, ground styrofoam, coarse vermiculite, coarse sand, lime, Milorganite.
For "dirt growers": (see also Growing Orchids in Mud)
A "seldom-repot" mix for all genera:
Rockwool. Inert and will need all nutrients supplied. Old Mill Orchids (KY) has good success with this. The epiphytes are grown in 40% repellent, 60% absorbent with other types with a greater proportion of absorbent. Others mix with styrofoam (peanuts near bottom, smaller near top), 7 parts to 3 parts of rockwool, plus fine or medium bark and perlite (brings Ph down from 8 to 5) (recipe is as follows: 2 parts fine or medium bark, 2 parts medium grade absorbent rockwool, 3 parts perlite, 7 parts fine (peas size) styrofoam and lots of water). May be used without bark (listserv). Other mixes suggested on the list--50/50 rockwool to perlite with chicken grit on the top; 3 parts perlite, 8 parts fine styrofoam, 3 parts ParGrow, 2 parts medium bark. Rockwool may get stale and/or contaminated and need to be repotted annually.
Terry Glancy of Pine Ridge Orchids uses a mixture of hydrophilic and hydrophobic rock wool with Aliflor, perlite, aerolite, coir and a little bit of bark (more for paphs) mixed in to break up the rock wool and let it crumble easily. He has also used AgroDiamonds that hold water (purchase from RA/AG Enterprises - 10104 150th Ct. N., Jupiter, FL 33478 --- (888) 729-2476).
Another grower on the Orchid List Digest suggested 1/2 sphagnum, 1/2 osmunda fiber.
Builder's sand may be a good natural source of silica. Orchid List Digest
Tire crumbs can be used either in a mix (as an inert ingredient) or as the growing medium. Available in several sizes. Will not decompose, so no root disturbance. No dust. Orchids 66:11:1168
Llama manure may be an acceptable alternative.
Coconut fibre is becoming increasingly popular. JEM Orchids uses Aliflor and Charcoal half and half, then add Coco-peat to desired moisture content from 10% - 30% of A/Ch volume ie. 5 gal Aliflor, 5 gal Charcoal = 10 gal add 1 gal coco-peat for 10% mix. Don Garling uses 1/3 each of coconut (large or small chunks or a mixture of them) sponge rock and expanded clay.
It may take two layers of 50% shade cloth to actually get that much
shade. Rentoul, Specialist Orchid Grower, 19 Aluminum
shade cloth (Aluminet) actually reflects heat, and is more
effective than black shade cloth, and can be cut to size (no need
to hem). It can be gotten from Green-Tek (sometimes advertize in
the Bulletin). Orchid List Digest
Use 4 Tablespoons of TSP (trisodium phosphate) per gallon to
sterilize cutting tools. 5% Clorox will sterilize, as will heating
at 400 for 2 hours (razor blades). Orchid Advocate 7/93, 151
Use shears with thin cutting blades; close shears; put in
flame for 5-7 seconds (will hiss if placed in water). Pots can be
sterilized in water with 1 lb TSP/5 gal (can be kept--does not
evaporate or lose strength like chlorine bleach), wear eye
protection and plastic apron, keep away from kids ( Bob
Hamilton on Orchid List Digest ). Someone else on listserv
does 350 for 1 hour (razor blades).
Another method is 2 seconds in a fresh mix of 1 part household bleach, 5 parts of water, followed by a rinse in a mix of 1 part vinegar, 5 parts water, 1 tsp. salad oil. Orchid List Digest
Moisture-loving genera may benefit by a wet bench. It has a solid
top and edges, and has some solid material like gravel to retain
moisture for an extended period. It may be topped by a layer of
growing spaghnum moss. Rentoul, Specialist Orchid Grower, 8
To sprout old backbulbs, simply throw them in a bucket of water and
wait! Orchid List Digest
Air Circulation is important, may wish to pot
high in the pot, or hang plants. Orchid Advocate 11/92, 214
Buds At base of newer, almost mature growths--fat and pointed like a bullet, splitting the petiole base of the outside leaf. Orchid Advocate 9/91
Dividing Keep newly-divided cymbidiums dry at the roots for 4 to 6 weeks (encouraged new root growth). AOS Bulletin 4/94, 392-3
Fertilizer Balanced at half strength late spring through autumn. High nitrogen can be used early, with high phosphorus later (July and later). Leach salts. Orchid Advocate 9/91 Epsom salts in early summer (1 Tablespoon per 6" pot). Feed only on bright, sunny days. Orchid Advocate 11/92, 214 Cymbidiums like potassium, so feed with something like 10-5-12 Orchid Advocate 7/93, 151
Flowering 3-4 months after summer rainy season starts, and when wide diurnal temperature range ceases. May be initiated by one or both of these. Orchid Advocate 9/91 Bright days and cool nights in the fall. Orchid Advocate 3/93, 62
Humidity 80% summer and autumn; spring is 60%. Orchid Advocate 9/91
Light Bright in winter and spring; cloudy in the summer. Transitions in October & April. Orchid Advocate 9/91 Foliage should be jade green, not pale yellow and burned or too dark. Mature plants need 20-40% shade. Filtered light all day or full morning sun is adequate. Orchid Hunter 8/91 As much as possible, short of injuring foliage--grassy yellow-green. Too much shade is a common cause of non-bloom. 4,000-6,000 foot candles during the growing season. Do not change orientation to sun when spiked, or give too much light during bloom. Orchid Advocate 11/92, 213
Mix Open and fast draining. Small bark, tree fern, perlite, charcoal. Possibly use large bark in the mix in the bottom of the pot, and small in the top. Orchid Advocate 9/91 Bark and medium perlite (3:1) with dolomite lime, single superphosphate and some 3-8-0 fertilizer. Rockwool (70% retentive, 30% repellent) may also be tried. Orchid Advocate 11/92, 214 f. Picture of cymbidium grown in horse manure
Repotting Every other year, when new root growth starts (late winter or after flowering). Orchid Advocate 9/91 Every 3 to 4 years Orchid Hunter 8/91 Rentoul recommends frequent repotting (every two years Specialist Orchid Grower, 46 . It is important to know if a clone blooms on the new growth or the previous year's growth.
Temperature Summer--66-80 F; Winter--38-67 F. Orchid Advocate 9/91 Above 40 and under 90 are ideal. Damage to spikes at 27 and plants at 25. Spikes are initiated in autumn with a large diurnal temperature differentiation. Orchid Hunter 8/91 Water. Very heavy from late spring through early autumn. 6 months wet; 4 month dry rest period (Dec-Mar) with transition periods. High humidity during dry period with dew (misting). Orchid Advocate 9/91 Young plants seem to like heat at the root zone (70-75 while the air is 50-55 during the winter).
Water Very wet in summer, during winter drenched and allowed to become almost dry (but not bone dry). Leach for salts. Like misting on hot days in summer. Soluble salt level should be 25-50 ppm, not more than 100 ppm. Leaf tip die- back due to too much salt. Orchid Advocate 11/92, 213-14
Misting Mist with cold water on summer evenings to reduce temperature and extend daily diurnal temperature variations ( Orchid List Digest, from Merritt Huntington ).
Japanese forcing methods (see Orchid Advocate 1/93:20 ff. ). Flowering bulbs should start between October and December (others pruned off). Flowering bulbs take 10- 12 months to mature. Prune off those that start in the spring or summer. For a report on an experiment with mekaki, see Orchid Advocate 7/94:148 ff. Prune in spring and summer. In July and Nov., given a 1/4 tsp Mag Amp 7-40-6 time release fertilizer. Every two weeks from Aug. to Nov., 6-30-30 no urea, every two weeks in Dec. and Jan., 0-50-30, Mid-Jan. to April, 1/4 tsp. 20-5-5 time release fertilizer. Also from Feb. until July, 21-7-7, no urea.
C. calceolus likes a saturated soil and can be grown in a bog (line
a 2' x 4' hole 12" deep with a 3-mil plastic liner, fill the bottom
with 6-8" of silica sand, fasten the lip of the plastic to a wood
frame at the height of the sand--to allow drainage-- and fill the
rest of the bed with a mix of 1 part oak leaf/pine needle compost,
1 part silica sand and 1 part soil). Place the plant about 2" from
the top of the mix. Sun morning and evening, shade in the middle.
Mulch in winter. Other cyps grown here include montanum, reginae.
Fertilize in spring. Can also be grown in good loam with a good
mulch. Calceolus and reginae can use the following soil--1/2 peat
humus, 1/4 perlite/vermiculite, 1/4 sand, plus lime. Give light
shade. Orchid List Digest
C. acaule--pure decaying oak leaves or pine needles in light to full shade. Acidic loam under white pines, mulch with needles. Freeze in winter. Good drainage to dry. Orchid List Digest
Try growing on cork with a pad of NZ spaghnum Orchid List Digest
Light. Brightest possible. Full sun in summer.
Water. Copiously during active growth (daily during summer; less in fall and winter).
Fertilizer. Never with high-nitrogen fertilizer.
Temperature. Doesn't flower well when kept too warm. Grows to 35. Place outdoors early and bring in late.
Potting. Small a container as possible. Fine bark (4") over plastic chips. AOS Bulletin 2/93:156 ff.
They are a sun-loving group. Potting material should be coarse. They mature their growth well before flowering period (spring). In habitat they bloom almost from top to bottom. Very little water needed in winter until new roots appear, and then sparingly until vigorous growth commences. Roots should never become completely dry. Almost impossible to overwater in summer. Rentoul, Growing Orchids, v. 3, p. 157-58
By late autumn the growths should be completed, fattened out, and change from mid-green to green-yellow. This ripening is not necessarily the stage for bud-setting. At this time the shade should be reduced. Once the swelling of the buds is noted, be very careful of overwatering. Rentoul, Growing Orchids, v. 3, p. 168
Maximum light required (can take full sun as long as there's adequate air movement). Begin watering when flowering starts. Place outdoors early; daily water by summer. Stop watering Nov. 1 until blooms open. Plenty of nutrients; do not use high-nitrogen fertilizer (10-30-20 in summer, 0-44-20 in fall). Can take down to 29. Place out early, bring in late (watch for fall rains). Should be pot-bound (infrequent repotting), in medium bark. AOS Bulletin 2/93: 158 ff.
Dendrobium, phalaenopsis type
Don't let them get cold; control fungus; give lots of sun and air (high humidity apparently not a requirement) Also keep warm, high humidity and light (full summer a.m. sun), lots of water, open medium (coarse tree fern in a clay pot or basket) Orchid List Digest
These are essentially terrestrial orchids, which need to be wet and
not hot. They also like fresh air. Acme Orchids uses the
following mix in a net pot--1/3 vermiculite (the good ingredient),
1/3 perlite, 1/3 redwood fiber (or substitute peat). Burkhardt and
Pui Chin use NZ spaghnum. They grow like weeds and seem to like
coming out the sides of the pot. They are also not necessarily
reliably perennial, but are easily grown from seed. Someone on the
Orchid List Digest noted that clear, mineral-free water is the most
essential element in growing disas, and that he has seen them take
up to 102 degrees in Baltimore with no problem as long as the water
See AOS Bulletin, July 1994, p. 766 ff. Repot in Oct. in NZ sphagnum, temps can go into 40s, 50% shade in summer, water 2-3 times/week in summer, once per week in winter. Good water--never let them dry out. Fertilize every other week with 1/4 strength 20-20-20.
Like bright light, good water (pure rain water, no fertilizer), pure peat moss and pots in peat moss also. Another grower uses air cone pots, a mix of 3-1 of spaghnum and perlite, and has standing in water. Very little fertilizer. Likes to have live spaghnum on surface. Orchid List Digest
Wally Orchard (disa list) uses a mixture of sphagnum and perlite as a medium.
Disas for the New Millennium by Sid Cywes
Equitant oncidiums (tolumnias)
Kenneth Wilson's advice is as follows. Use cedar shingles (not
pine) or use small pot. Very bright light. Mist in the morning,
be sure it's dry by evening. Little fertilizer (use fish
emulsion). Use soft water. Double pot (styrofoam or charcoal in
larger pot) for more humidity around plant. Medium--small charcoal
with small fir bark. Mist outsides of pots to increase humidity.
AOS Bulletin (5/91) makes following suggestions. Mount plants on cork, and then set them inside 2 1/2 inch pots, possibly with sheet moss around the roots.
Media. Larry Galdes recommends using NZ spaghnum, mixed with any of the following (or all): large perlite, charcoal, long tree fern fiber. Water every 4 days or so as it dries out. Too much misting causes algae. At 1990 Greater Lansing show observed fine specimens growing in pure tree fern.
Krull reports ( AOS Bulletin 2/92 ) that they need lots of air. He has best success in small clay pots in a 50/50 mix of medium tree fern and fine #4 grade charcoal. They can be grown this way very hot. They must have rapid drainage, and are misted daily.
Other options are tree fern and charcoal (50/50) in pot; peanuts in bottom, fill clay pot with charcoal; mounted on cork or treefern; potted in repellent rockwool (Indiana OS show--11/93).
Pot in clay pots with broken clay pot sherds inside; huge amounts of air movement (need to be swaying in the breeze). Orchid List Digest Another option is very coarse bark (1/2" size) in 2-3" pots; daily watering with pure water; 50-70% humidity; 100-1500 foot candles; warm temperatures. Another grows with cool nights, clay pots, constant humidity without wet feet. Orchid List Digest
Article in August 1994 Bulletin (p. 904 ff.) Intermediate temperatures, 50-70% humidity, bright light (between phals and catts), must dry out between waterings (mist mounted plants daily). Mounting is the method of choice. Pad of moss of coconut fiber around the roots. If that's too dry, set mounted plant in clay pot, if it's still too dry sift potting mixture around the base of the plant in the container (porous).
My observation of FL growers is that placing them in a wood basket with perhaps some aliflor or other expanded rock in the bottom seems to produce excellent results.
Culture. Plastic pot with a mix of 3 parts bark, one part perlite
and 1 part charcoal. Temp. 45 min. - 60 max. AOS Bulletin
Users in SF area use a lot of NZ spaghnum for this. Many respond
to intermediate conditions (50 to 80). They need a 15 degree
temperature differential (particularly in summer). High humidity
helps (70-100%). Air movement is also important. Relatively shady
conditions (1,000 to 1,400 fc). Leaves should be medium to light
green. Water often (moist but not wet). Not heavy feeders (too
much food causes leaf burn). Mix should be free-draining yet
moisture retentive. Can contain fine bark, medium grade tree fern,
NZ spaghnum. Early spring best time to repot (not summer).
AOS Bulletin 4/93:401f Plastic rain gutter netting, folded
over and filled with NZ spaghnum is good. Orchid List Digest
Another on the listserv is growing in marbles and clay pot
(water with 1/4 strength fertilizer every 2 days).
Try growing in marbles in a clay pot! Orchid List Digest
These are not cool-growing like odonts and masdevallias, though
they do not like hot weather. They should be grown 58-upper 70s.
Light levels should be like phals. Repot annually in tight pots.
Humidity should be 55-70% (information from Beall Orchid Co. order
form). Orchid Zone uses rock wool with excellent results.
Generally they like it cool and damp (see above under wet bench).
With a wet bench, use terracotta pots in direct contact with the
bench or plastic pots elevated above the wet bench. It is also
possible to double-pot them. Best grown with moving air. They
also appreciate some shading. In growth much of the year, so can
be repotted when in growth. Cultivate growing spaghnum moss on
surface of pot. Rentoul, Specialist Orchid Grower
Grown in small clay pots, odontoglossums do not need a great amount of nutrient at any time in their annual cycle. Once the spike commences, the watering should allow for the merest hint of dryness. It is natural for the pseudobulb to shrivel a little at this time. The plants are seldom entirely inactive, although they may be so for about 2 months following flowering. Rentoul, Growing Orchids, v. 2, p. 184
Terry Root (Orchid Zone) grows his odonts in rockwool and reports very good success in doing so. Charles Marden Fitch ( AOS Bulletin 2/92 ) uses NZ sphagnum moss set over a layer of charcoal or straight NZ sphagnum for odontiodas. He pots them in a small clay pot with porous mix, giving cool temperatures and bright light in winter. Larry Sanford, from Greater Cincinnati OS grows in wet rock wool and coarse perlite in an air cone pot.
AOS Bulletin article (4/92: 335 ff.) gives these directions: 50/55-70-80; 50% humidity; good air movement; 500 to 4,000 foot candles of light; mix--3 parts of bark to 1 part perlite; repot in fall or spring when new growths are 2-3" tall; neither swamp or completely dry.
AOS Bulletin article on odontoglossum and oncidium intergenerics (1/94, 10 ff.) gives these directions--high humidity, good air movement light (1,500-4,000 foot candles), constant moisture at the roots, but with good drainage, moderate amounts of balanced fertilizer. Report phenomenal success with 70:30 (absorbent: repellent) rockwool.
Bob Hamilton on Orchid List Digest recommends this mix: 50% bark, 25% perlite, 25% rockwool. This is what is used at Sequoia with good success.
In their native environment, the dormant resting period may be
almost totally arid for up to 6 months of the year. Despite severe
shrivelling of the pseudobulbs, the plants fatten out again
completely when the new roots begin to feed the plant.
Rentoul, Growing Orchids, v. 2, p. 190
The Ladyslipper Page is an excellent source for all kinds of information, including taxonomy and culture.
Air Essential at roots. Use medium bark in mix and/or "peanuts" (not concave ones). Flowers on long stems should be barely moving. Fans under bench are helpful. Novelty Paphs, 20
Light Should barely see shadow of hand at 12" above plant. 1,000 to 2,000 foot candles ( Novelty Paphs, 19 f. ). Klehm uses either 63% or 75-78% shade in summer (varies). Duane McDowell
Potting Use eggshells or oyster shells in mix. AOS Bulletin 8/91 May is the ideal month for repotting. Bulletin 5/92 Some growers pot in sheet moss, particularly for parvisepalums. Orchid List Digest Put nothing in bottom of pot; new mix every year; use sand, coarse vermiculite and lime in mix (60% calcium carbonate--or dolomitic limestone). Duane McDowell California growers use lava rock in their mixes. Bone meal in mix provides both calcium and nutrition. Orchid List Digest Eric Young Orchid Foundation (Alan Moon) recommend using rockwool for multiflowered paphs). AOS Bulletin 10/93, p. 1026 Perlite, limestone, charcoal, Green Sand also recommended Bulletin 119/3, p. 1155 A teaspoon of lime in each pot every so often leads to improved growth Orchid List Digest
Temperature Cool or intermediate. Mottled leaves can take higher temperatures, but will tolerate cooler ones. 55-80 F. is ideal. Reluctant bloomers (e.g. roth) may need fluctuating temperatures over several seasons to set buds. Novelty Paphs, 21
Water Can be taken up by leaves. Can dry out more than most people realize. Flush regularly and use good- quality water. RO water needs trace elements every 3-6 mo. and regular feeding. In fall and winter do not let water stay in leaf axils. Novelty Paphs 20 f.
Chinese paphs (parvis). These need lots of light, with wet/dry, cool/warm seasons. Cool nights in late summer and early fall (with 30 degree temperature differentials) may be useful. Bulletin 6/92: 598 Sheet moss is used as a medium by some growers. Orchid List Digest Use big pots, lots of water, bright light and good air movement. Duane McDowell
A magnificent Haynaldianum was observed at the 1995 Madison show growing in pure NZ spaghnum.
Philippinense Dry out for 2 weeks at end of February. Duane McDowell
Rothchildianum may prefer full sun in summer (listserv). It also likes to be over-potted (may use medium bark in the bottom). Orchid List Digest
Sanderianum wants warm nights. Terry Root
Following is the "Standard Paphiopedilum Culture" used by Fox Valley Orchids:
Light: adult plants like 12,000 Lux in summer, 18,000 in winter. Seedlings like 9,000 Lux in summer, 12,000 in winter.
Temperature: adult and seedlings like 80 days and 70 nights in summer; in winter adults like 72 days and 62 nights; seedlings 76 days and 66 nights.
Humidity: summer 80%, winter 50%
Air movement: adults, high; seedlings, moderate.
Watering: pH between 5.5 and 8.0 in order to get nutrients. Can't be overwatered if mix is good. Summer adults get 2 x week and seedlings 3 x week; winter adults and seedlings get 3 x week. May wish to consider Culligan weak based demineralizer instead of RO (pay for each tank rather than rental).
Fertilizer: 1 Tablespoon/gal of Epsom salts in fall and spring. Live in a nitrogen-poor environment. For demineralized water, use 1/2 or 3/4 t. every watering. Peters Excell Cal-Mag excellent fertilizer; GroMore is good for hydroponics (all nutrients). For regular water use 1/8 t/gal every 2 weeks in winter, 1/4 t/gal every 2 weeks in summer. Because of calcium needs, Peter's Excel Cal Mag a good fertilizer, along with straight calcium nitrate (1 Tablespoon/gal) every three weeks (listserv). Another writer suggested 1/2 teaspoon of calcium nitrate every 2 weeks (he got 500 g. of the tetrahydrate from Aldrich for $16.90). May want to limit this to 2-4 times/year (some growers use on all orchids).
Repotting: adults every 18 months, seedlings every 12 months. Leave some mix clinging to roots when shaking out. Harvest moss by liquefying it in blender and placing 1 t./pot. Purchase pots directly from McConkie in or near Tacoma, WA.
Dividing: adults when plant is too large for a 4" pot. Do not divide into less than 4 growths. Dust wound with Roottone. Don't divide mechanically. Water immediately and daily for 7 days.
Insect/disease control. Sunspray or 90% isopropyl for contact kill. Phyton 27 (OFE) for rots; GreenShield (similar to Physan but not phytotoxic--Florist Products) for general disinfectant.
No NZ spaghnum in paph mixes. Don't crock pots. Try to get ingredients that are the same size.
For newly deflasked paph and phrag seedlings (do not put directly in 2 1/2" pots): 8 parts Sequoia brand seedling bark, 2 parts Krum coarse perlite, 4 parts coarse Garden Magic peat moss (Franks), 1/2 c steamed bone meal, 1/2 c. dolomitic lime powder, 1/2 c Super Gro (trace element powder). Mix material dry in plastic garbage bag and store in plastic garbage can with small holes in bottom for drainage. Season mix before use by running water through it 3 times/day for 5 days. Keep covered. [a "part" is a standard 6" pot]
For seedlings coming out of community flats into 2 1/2" pots, and for repotting at smaller than 4" pot size: 12 parts Sequoia seedling bark, 2 parts Krum coarse perlite, 2 parts #3 charcoal, 1/10 part dried oak leaf mold (Frank's Nursery), 1/2 c dolomitic lime powder. Same standard and mixing as above.
For adults (over 4" pots) use 6 parts seedling bark and 6 parts medium bark.
This is the mix used by Terry Glancy of Pine Ridge Orchids (Florida):
Potting. Clay pot, lined with NY Spaghnum (1/2"-3/4"), filled in
around roots with foam packing chips with a layer of moss on top of
the chips. AOS Bulletin 2/93:143
Tips from Dick Wells (Hilltop Orchids)--Mid-America Orchid Seminar (South Bend, IN, Sept. 18, 1993): minimum ordinary night temperature of 63, except for 6 weeks in fall, when 58. 85 should be maximum day temp. in summer. 2-3 drops of Greenshield in water should help stop rots before they start. He grows in ProMix BX or MetroMix 360, with bottom third of pot in "peanuts." Color is enhanced with 1 tsp Epsom salts/gal. every 1-3 months. 1/2 teaspoon/gal of calcium nitrate every 6 mo. is also helpful. He suggests a daytime humidity of 50% and good air movement. He uses 4 1/2" azalea pots half full of peanuts as compots. He uses Knox- Out (Florist Products) 3/year. Bottom heat is also useful to young plants (especially in fall). When potting, dust broken places with BanRot, Terrachlor or Captan. The following mixes were recommended on the listserv: rockwool mixed with perlite with some chicken grit on the top; 2 parts Pro-Mix, 1 part medium fir bark, 1 part large perlite, 1 part chopped "peanuts."
Light--bright. Temperature--58-85. Water--lots (purity helpful),
acidic helpful. When in doubt, water anyway. Pot in spring using
mixes of medium and fine bark, charcoal, spaghnum, perlite.
AOS Bulletin, 6/91 Some growers report good success with
Fox Valley recommends 50% of their paph mix, and 50% Pargro horticultural rock wool.
Clark Riley (firstname.lastname@example.org) has best success in air cone pots (presumably in bark mix) in trays of rain water. Here is his description:
I have grown hundreds of Phrags standing in trays of rainwater. For me, this change marked the upward turnaround in this genus. I use aircone pots sitting in plastic trays with the water filled to the level of the openings at the bottom of the aircone pots. Once a week, plants are removed from the trays, flushed with fresh rainwater followed by a very light fertilizer watering. The trays are rinsed and drained, the plants are returned to the trays and water is added to the vent level again, not watering through the mix.
Fresh water is critical. Don't let it sit or it builds up foul-smelling, fatal toxins. When one reads the literature on this genus, the term "trickling water" or equivalent comes up over and over. Under my conditions, roots fill the pot and go wandering out into the tray water.
It was reported that phrags do better when potbound. Orchid List Digest
Besseae. Cool nights will give larger, better shaped and more brightly colored flowers. Terry Root Orchids (61:12:1226)suggests that they are shady growers, preferring 1800 foot candles.
Fertilizer. In summer, supplementary fertilizing can be done by
placing rubber-topped plastic flower tubes containing stale beer
(!) on a rigid, emerging new root. AOS Bulletin 8/92: 7/94
Pruning. The Whackerback method, cut the top off an ungainly vanda leaving the top with at least 4 strong roots, and the bottom at least 12" of growth above the container. Seal the cut ends. The lower part (with several growths) is what's really wanted AOS Bulletin 8:92: 796
See November 1992 AOS Bulletin (116 ff.) for growing
information. Vanilla extract can be made with 1/2 cup cognac and
4 vanilla beans, halved lengthwise. Cut beans, submerge in cognac,
steep for 2-3 weeks. Vanilla sugar can be made with 2 cups of
granulated sugar and 1 vanilla bean, split lengthwise. Cover bean
with sugar, store for week in closed container, shake occasionally.
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