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!

July in Your Orchid Collection

July Climate Data

• Average high: 90.9

• Average low: 76.5

• Average mean: 83.7

• Average rainfall: 5.79"

Excerpted from Florida Orchid Growing: Month by Month by Martin Motes. All rights reserved.

    Although it mostly passes unnoticed to millions locked in their air-conditioned bubbles, July in South Florida is quite different from June. While the pattern of afternoon showers built from the moisture of the morning’s sea breeze persists in July, the thunder-storms are sharper and shorter. The clouds linger less and the foliage dries more quickly. Less quantity of rain falls in July than in June and periods of several days typically pass without a drop. This is good news for orchid growers. July (and August) allow orchidists to focus on the first essential of orchid growing, drying the plant out.

            Frequently, neophyte growers ask “What if I go away for several weeks in the summer and there is no one to water the plants?” The response is “That’s wonderful”. Experienced growers use the break in the rainfall during July and August to dry their plants “hard”. Depriving orchids of water for several days until they and the media or baskets they grow in are bone dry is essential to good orchid culture. By drying the plants hard, one deals a severe blow to orchids natural enemy, fungus. Orchids have evolved to withstand drought because fungus can not. During severe drought fungus’ only defense is to cease all growth and retreat into a spore stage. Hopefully (and with good cultural management) these pathogens will not be aroused from this slumber until the first drizzle of September sets in, allowing our plants two months to mature and harden their growth making them less vulnerable to the September conditions which give some advantage again to the fungi.

            Careful watering and judicious drying will do more than any other practice to ensure healthy plants. Drought is the orchid plants armor against disease. Be sure that your plants dry as completely as the weather of July permits. Nonetheless, as our plants are in full growth they need adequate water in July therefor after a hard drying, orchid plants need a thorough re-hydration. If the next rain fall is insufficient to saturate pot, roots and media, the grower should add to the natural moisture until he is sure both roots and media are saturated, using two or three applications of water spaced a few minutes apart. When the plants stop dripping is the time to apply the next dose of water. Don’t stop watering until the “heft” of the pot tells you that it is holding as much water as it can. More typically in July, orchidists should use these opportunities when more moisture is required to substitute fertilizer for water and saturate the roots and the media in the same thorough manner. In July typically think of fertilizing rather than watering. Weekly application of a commonly available balanced fertilizer (20-20-20 or 18-18-18) at two teaspoons per gal. will supply the nutrients that our plants require in this period of lush growth. This balanced formula should be alternated every other week with potassium nitrate and Epsom salts (one tablespoon each) to supply the extra magnesium and potassium we now know are plants need on a regular basis. Even better (although not so readily available) lower phosphorus fertilizers containing extra magnesium and calcium with a formula like Peter’s Excel (15-5-15) have been shown to be the precise fertilizer our plants need. This formula is recommended year round. Hopefully such orchid specific fertilizers will become more widely available. Lowering the phosphorus intake of our plants is particularly important in South Florida because of our alkaline water. Always apply fertilizer in the same way as water, in two to three doses spaced a few minutes apart. Apply the fertilizer to the point of “run off” IE.when the solution starts to fall off the plants; stop and move on to the next plant. Repeat the application a few minutes later when the plants stop dripping. In July more than ever, never, never follow the frequently heard and disastrously bad advice of watering before fertilizing. Always substitute fertilizer for water: now and at every season. Roots saturated with water cannot absorb fertilizer but the prolonged wetness can rot your plants. Don’t give fungus the upper hand by wetting the plant’s foliage and roots more often or longer than necessary. Careful watering is especially important throughout the rainy season.

            The wise orchidist will have long since finished all of his potting of sympodials and the top working of his vandas but for the rest of us this is the eleventh hour. Autumn is closer than we think and vandas will need at least three months to settle in to their new baskets or pots before the first chill of October tickles their root tips. Unless you can protect them thoroughly from cold, Vandatop cuttings and keikies should not be made after the end of July. If you do take cuttings remember the “3 root rule”. Count down from the crown and make the cutting beneath the third or fourth root. Keep as many leaves as possible on the stump and you will be rewarded with a greater abundance of offshoots. Always slip the sterile knife or shears down between the stem and the leaves and then cut transversely to save as many leaves as possible. Be sure to anchor the cutting firmly in its new lodging. Tie them up and tie them down! There is no time for mistakes in July.

            Thrips are much less of a problem in July as the rain tends to wash them away and doubtless there is an abundance of other lush fodder for them elsewhere in our yards. They can reappear in a prolonged patch of dryness, so if you need to think of watering in July it may be dry enough to worry about thrips. A prophylactic spraying for thrips in July will also put a damper on scale crawlers. If a second spraying with soap follows the first by seven to 10 days, the population of mites will be scotched as well.

Treating Cold Damaged Orchids

Cold damage appears on orchids as whitening of the foliage and stems. The white gradually turns to brown as the effected tissue dies. Often this dead tissue simply dries and the damage is limited to the unsightly patches that are left. Frequently, however, the damaged tissue is infected with bacterial rot which can spread in the plant and cause further damage. 
 
Softening of the edges of the cold damaged areas or oozing of brown fluid indicates bacterial infection. Removal of the leaf or stem is a simple but somewhat drastic solution. If one is loath to lose so much of the plant, the most effective treatment for bacterial infection is treatment with cupric hydroxide (Kocide or Champion) which should if possible be combined in equal parts with mancozeb (Manzate or Dithane M45). 
 
This combination is packaged, pre-mixed as Junction. By adding a small amount of water to the chemicals in a jam, one can make a slurry that can be brushed on the lesions.

Be cautious when making the slurry not to inhale any of the dust and never, never, dust these chemicals without wearing a mask.

An old toothbrush is efficient in applying this and your dentist will be happy to have it out of your mouth. Any left over slurry can be placed on a high shelf (brush and all) and re-hydrated later. This stuff is also the cure for those soft spots that appear on Phal. leaves in summer. 
 
For large collections, with extensive damage, one tablespoon per gallon of cupric hydroxide and mancozeb can be sprayed. Mix the two and wait an hour or more before spraying. Do not apply this mixture to dendrobiums which are hyper-sensitive to copper or to bromeliads (ditto).