December in Your Orchid Collection
Average high: 77.5
Average low: 62.2
Average mean: 69.9
Average rainfall: 2.18"
Excerpted from Florida Orchid Growing: Month by Month by Martin Motes. All rights reserved.
December marks the beginning of the serious dry season in South Florida. While this additional dryness provides relief from the autumnal rains that can bring so many fungal problems, December is also the month of shortest day lengths. This contracted period of light, on the contrary, reduces severely the drying potential for our plants. Nature thus both gives and takes away from us in December. We must make sure, therefore, that we do not aid the dark side of the force by improper watering. In December, above all, one must stick strictly to the two cardinal principles of orchid watering: water early in the day so your plants have as many hours as possible to dry, and water heavily when you water, allowing longer intervals between watering to dry plants thoroughly. This practice maximizes the benefit of the dryer air of December and minimizes the adverse effect of the shorter day lengths.
When nature has delivered a light overnight or early morning rain as she so often does in December at the leading edge of a cold front, add to her efforts by watering thoroughly that same morning and skip out watering for an extra several days afterward. With this method you can use the general dryness of December to give yourself much of the advantage of a greenhouse in terms of controlling watering. As in all aspects of orchid culture, keen observation is the key to success. In cooler weather your plants need much less water. Moreover cool air even at the same relative humidity, strips less water from your plants because cool air has less water holding capability. Always be sure that your plants really need water before you roll out the hose in December. Remember to use at least one of the standard tests for dryness: the finger dug slightly into the media test or the newly sharpened pencil coming dry like a knife from a well cooked custard, or test by hefting a pot that you know the weight of, both wet and dry and be sure that it has attained sufficient lightness. When you are sure they are dry, water them until you are sure they are very wet, then let the drying air of December do its magic to ward off leaf spotting diseases.
Himalayan dendrobiums of the nobile and Callista (D. aggregatum, chrysotoxum, etc.) Sections require no additional water (beyond rain) in December. Remember, those of you who water (or, even worse, fertilize) these dendrobiums in December, will be punished by having your flowers taken away in the Spring. Some growers who have the space, isolate these dendrobiums along with other types that want hard drying such as Catasetum, Cycnoches, Mormodes, and Calanthe. Another strategy is to hang these plants high or at the edges of the collection reminding oneself to neglect them and also to avoid watering them by mistake. Some growers achieve the same result effect by turning the pots of these genera on their side in November or December, to avoid catching water from whatever source. Plants of some of these genera that have finished flowering can even be removed from their pots and stripped to bare roots in anticipation of re-potting them in new media when they break growth in the spring.
Most sympodial orchids are resting in December and require less fertilizer. Biweekly or even monthly applications of a balanced fertilizer or 15-515 are still desirable. Nitrate nitrogen is the most readily absorbed in cooler weather; therefore at least one more application of the potassium nitrate/magnesium sulphate (at 1tbs. each per gal.) recommended in November is still a good idea. It’s good stuff! Vandas, Phalaenopsis and other monopodial orchids should be fertilized right through the winter although both the amount of fertilizer and the frequency of application can be reduced. Remember reddening of the foliage is not natural, nor is it a response to the cold per se but rather a symptom of nutritional deficiency. The plants are asking for more potassium and magnesium. Give them the groceries.
December can be cold. Frost has occurred in the first week of the month and unforgettably, the coldest temperatures ever recorded in South Florida were registered on December 25, 1989. If you haven’t taken some of the precautions outlined in the November Newsletter, get busy! Keep a close eye on the forecasts during this volatile month.
Remember that hard cane dendrobiums of the sections Spathulata and Phalaenanthe are the most sensitive of commonly cultivated orchids. They resent temperature much below 60 degrees F. Phalaenopsis are next most sensitive, then vandas. Protect all these genera more carefully.
If you are getting a jump on Spring potting chores by repotting sympodial orchids that have finished blooming, it is particularly important that you take extra care in securing them in their containers. These plants may not be sending out new roots for several months, enough time for them to be shaken loose from insufficient staking. Passing cold fronts can bring brisk winds in December. When new roots start to form on insufficiently secured plants, wind moves the plant and chafes the new root tips off. Improperly secured plants are never able to root properly and slowly pine away. If you love them you must tie them up, tie them down. This is also especially true of mass produced orchids sold in Home Depot, K Mart etc. The soft, peat based media used to grow these commercially produced plants in the controlled environment of a greenhouse often does not provide sufficient purchase to secure the plants in the rough and tumble of a South Florida orchid collection buffeted by harsh winter winds. You probably should have already re-potted these into more durable medium but until you do, tie ‘em up!
Keep those vandas, phalaenopsis and hard cane dendrobiums as warm as you can. Merry Christmas, Hanukkah, and Kwanza!
October in Your Orchid Collection
Average high: 85.4
Average low: 72.2
Average mean: 78.8
Average rainfall: 6.19"
Excerpted from Florida Orchid Growing: Month by Month by Martin Motes. All rights reserved.
October is a month of change in South Florida. If the Romans had lived here where we do, they would have named this month for their two faced god Janus. Usually around the middle of the month, and certainly by the end of the month, the first strong cold front pushes into South Florida bringing to a close the monolithic heat and damp of summer and ushering in weather as most of the continent knows it, alternating periods of warmer and cooler. Although warm temperatures will persist for another month or so until the technical end of the hurricane season, the tropics are in retreat and the temperate zone in the ascendancy. Each successive cold front foreshadowed by ever lessening rain storms will progressively cool our temperatures and dry our air. But days are shortening too, providing less hours of sunlight to heat the air and slowing the drying process. Nights are longer and cooler which produces the same effect, slower drying. Now we must start to move into the consciousness of winter and take greater care to insure that our plants are thoroughly dry before we water them again. The shorter days of October dictate that we rise even earlier to water if necessary. Each extra hour of daylight is to be cherished by us as well as our plants.
Most of our orchids are well aware of this sea change. The shortening days of late summer have told many genera to finish their growth and prepare to rest. We need to listen too. And look! The last smallest leaves of these highly seasonal plants will have unfolded at the tips of their new growths telling us that their growth cycle is finished for this year. Himalayan dendrobiums of the nobile type and of the section Callista (D. aggregatum et al.) now begin their five months of carefree existence in South Florida. They should be put in a bright spot and given no more water and above all, no more fertilizer until after they have bloomed in Spring. Catasetums, mormodes, Cycnoches, calanthes and other deciduous types should be treated the same way. Whatever moisture nature provides in the increasingly heavy dew and the passing rains that usher in most cold fronts will be adequate for these plants whose native environment is a seasonally monsoon one like ours. Benign neglect suits these genera just fine and what a relief to the conscience of the ever busy orchidist! The truly devoted will group these genera together, preferably at the edge of the growing area and high up where they will receive the maximum of light and air circulation. Grouped thus, the chance of an accidental watering of these while taking care of the more thirsty genera is minimized. Another strategy is to tip the pots of these dormant genera on their sides thus eliminating much natural rainfall and avoiding a misdirected hose spray. Some growers even remove plants that have finished both growing and flowering from their pots entirely. When new growth begins in the Spring they will receive a fresh start in new medium.
Many cattleyas, laelias, oncidiums and phalaenopsis-type dendrobiums will be finishing their growths and should be hardened off with reduced water and fertilizer but not the Spartan regime of the deciduous type. Lower nitrogen fertilizer applied at a lower rate and with less frequency will make these genera happy and prevent them from breaking into unwanted off-season growth that frequently hampers flowering as well. Many growers tend to use higher phosphorus, lower nitrogen fertilizers of the “Bloom Booster” type during the cooler weather. But less frequent applications of the recommended 15-5-15 is a better strategy. These applications should be spaced further apart as well, at ten to twelve day intervals. Less frequent watering will also do for these genera. When the frontal rains pass through, check to see that the pots are thoroughly wet by giving them the “heft” test and if they are not heavy enough “top them up.” Let them dry ‘hard’ before watering again. In cool weather especially, less is more.
Monopodial orchids like Vanda and Phalaenopsis which want to grow continuously, feel the change too. The broad swing of day to night temperature stimulates flower spike initiation in these genera. You can spur them on to greater excitement by giving them a shot of high Phosphorus ‘Bloom Booster’ fertilizer just before or just after the sudden drop in night temperatures precipitated by the passing of a cold front. For most of the year “Bloom Booster” fertilizer appears to be in fact “Bloom Blocker” but (perhaps from faith rather than science) high phosphorus seems to have the desired effect (perhaps from shock) when the first cold snaps are also halting vegetative growth. We like Miller’s Solugro (12-48-8) because it contains none of the ugly blue flower, clothes and hand staining dye. Other brands (with or without dye) are equally effective. Look for a very high middle number and a relatively low first number or ask at your garden center for a ‘starter solution’ which is the moniker for these fertilizers when used in planting out vegetable or annual seedlings. Because the nitrogen level is lower, you can use a full tablespoon of these or more, per gallon.
Cooler weather calls our attention to our plants’ needs for trace elements. Chief among these is magnesium, often described as the ‘major’ minor element. Magnesium deficiency shows up in orchids as a reddening of the foliage particularly when the plant is stressed. This color change is frequently attributed to cold as it occurs following spells of cooler weather. This observation is the fallacy of post hoc, ergo propter hoc; cold is merely the efficient cause: the material cause is lack of magnesium. Hopefully the new fertilizer regimen outlined in the July chapter will minimize or eliminate the reddening by keeping the magnesium level up in the plants. But... Epsom salts (MgS) is the best and most readily available source of magnesium. This can be applied with Potassium Nitrate (KNO4) at the rate of one tablespoon each per gallon. Potassium Nitrate has the formula 14-0-44. The missing number in the middle is Phosphorus. In combination with our highly alkaline water phosphorus tends to react with magnesium and the other metals of the trace element group. Never apply magnesium and the other trace elements in combination with fertilizers containing phosphorus. A general purpose trace element mixture can be added to the mix of magnesium sulfate and potassium nitrate at the rate recommended on the label.. (Concentrations vary). Goodbye red, Hello green!
September in Your Orchid Collection
Average high: 89.0
Average low: 75.7
Average mean: 82.4
Average rainfall: 8.38"
Excerpted from Florida Orchid Growing: Month by Month by Martin Motes. All rights reserved.
September looms as the only truly dismal month in South Florida. Even without the prospect of the unspeakable ‘H’ word, September disheartens since it is easily the dampest, dullest month in the year. Although more inches of rain fall in June, more hours of rain occur in the often slow, seemingly endless drizzles of September. Frequently a day or two can pass without so much as a solid hour of truly bright sunshine to lift our spirits and dry out our plants. Days are growing much shorter also, with long nights when our plants are wet from the frequent rains. Coming at the end of the rainy season when disease pressure has been building, September presents the maximum opportunity for fungal and bacterial diseases to take hold of our orchids. Hopefully careful watering practices and the judicial use of fungicides (as recommended last month) will have diminished the potential for disease in our collections. But even in the best managed collection, September calls for extra vigilance. Keep a close eye out for problems and remove immediately any plant that shows the first sign of fungus to a dry location to prevent the disease being spread by splashing rain drops. Good hygiene is particularly important this month. Clean up growing areas and remove any dead leaves, twigs or other organic debris from the plants and the ground. In September numerous diseases that linger in decaying plant material find the ideal conditions that allow them to jump to the living tissue of our prize orchids. Such problems can develop more quickly in September than in any other month. September is a month to stay home and be there for your orchids. Look at every plant, every day.
September, above all, is the month that the old Florida growers’ adage that "One needs a cat to grow good orchids," holds true. By leaving enough space between plants on a shade house bench for a cat to walk around without knocking them down, one provides the good air circulation which is absolutely essential in periods of protracted wet weather. Well spaced plants are much less likely to encounter disease problems this month. Remember that your plants will have grown considerably over the summer and that the space they occupied comfortably in the Spring has now been filled by their own growth as well as their neighbors. Space them out. Now is perhaps the time to decide to hang some of the larger ones where they will dry much more quickly. The small cute ones left behind on the bench will be very appreciative of the extra air and light.
Another excellent way to increase air circulation and enhance rapid drying is by trimming excess (particularly vertical) branches from all trees which support orchids or are near to orchid growing areas. By increasing the light and air flow one will also garner the benefit of reducing the possibility that such trees will be knocked down in a severe storm. Trees trimmed to permit proper air circulation and light for orchids were frequently the only ones which survived upright after Andrew. As there is rarely time to do such pruning when storm warnings are actually posted and creating extra debris is not then wise, now is the time to protect both your orchids and your trees. Days are shortening quickly now and more hours of rain and overcast skies mean that your orchids will benefit from all the additional light that they can get. Beginning the process of “hardening off” our plants by allowing more light to reach them will give them a leg up on the coming cool weather as well.
As orchids grown outside are so frequently wet in September, it is often difficult to apply fertilizer or fungicides to the plants because they are already damp. Catch 22! — the plants need extra protection because they are wet and because they are wet one can’t apply chemicals to protect them. In these circumstances, many growers find Quaternary ammonium compounds useful. Sold as Physan, Consan, Greenshield or Triathalon these disinfectants dissolve totally in water and can be applied to wet plants. Strengths vary so follow the label. Although Federal regulations say they should not, many growers substitute the cheap and readily available pool algicide which contain the same active ingredient. Home Depot sells a brand called ‘‘Pool Time’’ which could be purchased legally to disinfect walks and pathways at the rate of 1 to 2 tsps. per gallon and would certainly do no harm at that rate, if it came into contact with the orchids no more frequently than every 7-10 days.
This month when those brief periods of dry weather permit growers to think of applying other pesticides, they are tempted to think of giving their starving charges fertilizer as well. This is generally not a good idea with any fertilizer containing phosphorous (the second in the numerical series of three numbers). Phosphorus changes the PH of water and tends to interact with many other chemicals reducing their effectiveness. In September we need as much fire power from our chemical arsenal as we can get. A much better strategy in general to add some nutrients employs potassium nitrate (KNO3) 13-0-43 at a rate of 1 tbs per gallon of water. One should ask for the type usually referred to as ‘‘spray grade’’. In general sympodial orchids are reaching the end of their growth cycle as September progresses so a reduction in nitrogen from the potassium nitrate substitution or a missed fertilizer application usually does little harm to orchids grown outside in South Florida. Soft cane dendrobiums of the “Nobile” types will actually benefit from the reduction in feeding. It’s time to wean these deciduous types before cutting them off entirely from the grub next month. Vandas and Phalaenopsis on the other hand can be fertilized as often as weather permits and will bloom all the stronger for this extra attention in the coming months.
Snails can also be a problem again in September. Even if you earlier used the ‘‘lightly, frequently’’ baiting suggested in July, snails can travel long distances on wet ground in the dull, dark weather of September. Chances are your neighbors have not been as good as you on snail control. So, once more with feeling: snail bait "lightly, frequently" to give a warm welcome to any recently arrived mollusks. With an eye to the heavens (or at least to the TV screen), removing any old boards, empty pots or other debris that might fly about in a storm will also render the humble snails homeless. An opportunity to re-double your virtue and save some precious moments in the face of the storm that we hope never comes!
August in Your Orchid Collection
August Climate Data
Average high: 90.6
Average low: 76.5
Average mean: 83.6
Average rainfall: 8.63"
Excerpted from Florida Orchid Growing: Month by Month by Martin Motes. All rights reserved.
July and August are the two most similar months in South Florida. Most of the advice on watering, disease and pest control in last month’s calendar still apply but subtle changes are taking place. Although it may not seem so, as temperatures climb into the low nineties most afternoons, summer is in retreat: each day a little shorter, each night a little longer. With shorter days the importance of watering as early in the morning as possible comes to the fore. With less hours of sunlight to dry the plants, extra care should be taken in choosing when to water. Back to the basics of the classic saying : If a Vanda looks like it needs water, water it; If a Cattleya or Oncidium looks like it needs water, water it tomorrow. If a Paph or a Phal looks like it needs water, you should have watered it yesterday. If plants retain water even from an early morning watering, allowing them to dry a bit harder before the next watering is always a good idea. An extra day of drying rarely does harm.
August should provide numerous opportunities to dry each orchid to its desired level of dryness. Take the opportunity to dry your orchids "hard" at least once but preferably twice in August. This will give your orchids a leg up on their mortal enemies, the fungus, before the drizzle of September switches the advantage to our adversaries. August is definitely not the month to over indulge in water. September, the soggiest of months, is next up. The corollary to this calculated drying is the concept that when watering in August above all water thoroughly. If watering is necessary be sure that the roots and medium are totally saturated with the application. The drizzling rains of September are so detrimental precisely because they keep the foliage of the plants wet unduly long. We want our plants which are still growing to receive plenty of water but also plenty of drying time.
Good air circulation and proper watering are the keys to disease prevention. Remember that your plants will have increased considerably in size by this point in the growing season. They have added extra growths and extra leaves across the summer. August is a good time to evaluate the spacing of our plants. Remember the old Florida saw that one needs a cat to grow good orchids because when properly spaced a cat should be able to navigate the benches between plants without knocking them over. While we can not recommend specific chemicals, the county agent recommends Banrot, a convenient combination of Thiophanate-methyl and Truban which controls a number of leaf-spotting diseases and soft rots, for home owner use. A combination of Thiophanate-methyl and mancozeb has also been recommended. This can be found pre-packaged as Duosan. If one can over come the aversion to chemicals and can learn the safe application of them, they are valuable tools to better orchid growing. An ounce of prevention is worth a pound of cure especially before the soft, slow drizzle of September sets in.
Lengthening nights in August mean cooler nighttime temperatures. Many sympodial orchids are reaching the end of their growing cycle and require less nitrogen. Cattleyas and oncidiums have maturing bulbs. Genera that become deciduous in winter like nobile dendrobiums, calanthes and catasetums should be given much less nitrogen in August to prevent them producing an unwanted off season growth and perhaps forgetting to flower. Substitute an additional application of potassium nitrate and Epsom salt (1TBS each per gal) instead of the balanced 20-20-20. Vandas will respond well to this also, as several of the parental species of our hybrids produce blooms on shortening day lengths and lower levels of nitrogen in their fertilizer seems to egg them on. As explicated in the last chapter, modern research indicates that orchids require less phosphorous than previously thought. This concept should lead us to more judicious use of phosphorus. Fertilizer high in phosphorus may still be of some value at the end of the growing season, perhaps not so much as stimulus as shock. One or two heavy applications in succession, a week or so apart will certainly provide all the phosphorus and all the stimulus (or wake up shock) our plants require to bloom.
Snails can be somewhat of a problem in August too, but left to multiply they will be in their full glory when those slow unrelenting rains of September set in. Control them with baits in pellet or liquid/paste form. Remember, these are baits, the pests are drawn to them. Therefore apply lightly, but frequently. Because they wash away in the heavy rains, baits should be reapplied every two weeks. One pellet every two to three feet will do the job, but one application will not. Given a choice, the smallest pellets baits are best. They keep us from over applying and also pose much less threat to neighborhood pets. A small bait in a Vanda crown is a nuisance, a large bait can be a disaster.
If you have been waiting to make cuttings of the terete vandas or reed stem epidendrums, you can wait no longer. The potting season is drawing absolutely to a close. Pot up those overgrown phals before they even think of spiking. Re-set those strap leaf vandas early in August whilst they still have just enough time to re-establish themselves in the September humidity and before the cool weather arrives and their root growth slows or stops. As in all seasons be sure that the plants are firmly set in their containers. There is no "wiggle room" this late in the growing season to restart tender roots that have been chafed off a loosely set plant. As the cooler weather approaches try to give plants that have been repotted late more protection from the first cold snaps.
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