Motes Orchids 5/2/21 Motes Orchids 5/2/21

April in Your Orchid Collection

April Climate Data

Average high: 83.8
Average low: 67.6
Average mean: 75.7
Average rainfall: 3.36"

Far from the cruelest, April is the kindest month to South Florida orchid growers. The weather in April is definitely settled into warm, even deliciously hot, with passing cold fronts only adding the delight of a pleasant change in temperature. The clean, bright days brimming with abundant sunlight and the low relative humidity create the high drying potential that orchids love. Now we can get our orchids off to a great start on the growing season by practicing our very best watering skills under ideal conditions. Water heavily when you water and allow the plants to dry thoroughly before watering heavily again. Drying ‘hard’ in the Spring will produce benefits all season. We want to get our plants well launched while leaving all the fungi high and dry.

The new shoots of Oncidinae, grammatophyllums and dendrobiums are quite cup-like; care must be taken that water does not stand too long in these immature growths. Water these types very thoroughly with two or three applications of water spaced 10-15 minutes apart. Water should run freely through the pot on each application. Saturated thoroughly in this fashion the plants will need only weekly watering. Even more care should be taken with the soft plicate leafed genera like Catasetum, Mormodes, Cycnoches, Gongora, Calanthe and Thunia The new growths of this type are rolled together (the fancy word is convolute) like a collapsible drinking cup. These should be grown in water retentive media that should be saturated at each watering to permit the developing roots to have abundant water but allow the vulnerable new growth extra time to dry. Feel the weight of a pot when you have finished watering. Be sure it is heavy with water. If it’s not water one more time. With plants properly spaced, good drying should not be difficult in the hot dry air of April. But do be careful to water early enough in the day to allow the tender new growth to throughly dry by twilight.

With vandaceous orchids grown in slatted baskets, most growers find that they dry altogether too well in April. Vandas can be watered almost every morning in April. Indeed, a second light watering or misting in mid-afternoon in April and early May is often beneficial provided the crowns and leaf axils of the plants have time to dry completely by nightfall. Another strategy under high drying conditions is to bend the rules, at least occasionally, and water heavily in mid to late morning. Late waterings on weekend mornings (you didn’t want to get up early, any way) provide relief for plants that are more stressed on week days with their owners absent. Very occasionally, one needs to break the rules absolutely and water thoroughly (not just mist) in the mid to late afternoon so the plants can slowly absorb the water across the cool hours of the night. This is the season that one must be sure that Vanda roots have turned overall dark green when we have finished watering. Two applications of water to the point of runoff spaced several minutes apart should accomplish the required color change from white to totally green. Saturated roots are absolutely necessary to provide the plants the moisture the plants need to withstand the heat and dry air typical of April. Sometimes, particularly at this season, the roots will not change color even after the second or third application of water. This lack of response to water is because the roots have become so dry that they are repelling rather than absorbing water. They are behaving like a cork in a wine bottle. The grower must exert special effort to re-saturate the roots. Often this will require 4 or 5 waterings to the point of run off spaced 15 minutes apart. Once the roots have been changed to the healthy overall green, normal applications of water should bring them around in future.

With increased heat and light and the onset of growth, fertilizer becomes more crucially important to the plants. Balanced time release pellets (13-13-13) can still be applied to potted plants provided the duration is 180 days or less. Most time release fertilizer breaks down faster under South Florida conditions and should be exhausted by October when we will want our plants to slow down. The brand marketed at retail as “Dynamite” is generally considered by professionals as superior in reliability to other types. In April, 15-5-15 can be applied to most genera at the rate of 2 tsp. per gal every two weeks. Vandas, ascocendas, Aerides, et al will benefit from a full tablespoon of 15-5-15 weekly during this high energy period. One can also apply high phosphorous ‘Bloom Booster’ fertilizer once or twice at this time to stimulate them to flower for Mothers’ Day or failing that to win those trophies and A.O.S. awards at the Redland International Orchid Festival the next weekend. High phosphorous (we use Millers’ Solugrow 8-48-12) also stimulates root action and is important in getting all genera off to a good start on the growing season. This is one of the few times that high phosphorus is perhaps beneficial. During the rest of the year it is to be avoid particularly with our alkaline water. Current science recommends fertilizers lower in nitrogen, much lower in phosphorus and higher in potassium, magnesium and calcium. Peter’s Excel 15-5-15 is now the standard for year round use.

The warmth of April, alas, stimulates the growth of bugs as well as plants. Both thrips and mites thrive in the dry heat of April. Liquid dishwashing soap (at 2 oz per gal) will control both but be mindful that soap should not be applied to plants that are suffering from drought stress. Be sure that your plants are well hydrated before you apply soap. Water them extra hard the day before. To be effective soap must be used profusely. The plants should be washed in the solution to the point of wetting every nook and cranny of both the plant and its container. Only such thorough treatment can reach the reclusive thrips and be sure to touch all of the ever prolific mites. A second treatment at 7-10 days is necessary to control mites and a miticide such as Kelthane might be advised. Orthene which is the insecticide of choice for thrips (because of its residual action) is compatible with many miticides. Check with your county agent if in doubt.

April is the classic month to catch up with all the re-potting which you meant to do across the winter. New roots form fast in April; don’t rot them off by over-potting or break them off by allowing the plant to wiggle in the pot. Tie them up: tie them down!

April is a month for great moral decisions. When turning on the air conditioner for the first time, consider how much better an orchid grower you would be if you set the thermostat 2 or 3 degrees higher. You will find that you spend more time with your plants when you are accustomed to slightly higher temperatures and it is the master’s shadow that makes the plants grow. Besides spending more time enjoying your orchids, when the FPL bill arrives, you can celebrate with some splendid additions to your collection.

April is a great month for naturalizing orchids in the garden. Perhaps its time to think of new homes for some of our burgeoning collection.

Motes Orchids 3/12/21 Motes Orchids 3/12/21

March in Your Orchid Collection

MARCH CLIMATE DATA

Average high: 80.7
Average low: 64
Average mean: 72.4
Average rainfall: 2.56"

Whilst March never comes in like a lion in South Florida, occasionally it slinks in like a bob cat. Frost is not unheard of in the first few days of the month. The more cold sensitive genera, hard cane dendrobiums, phalaenopsis and vandas may well need some protection even into the middle of the month. Overall, however, March brings us some of the most ideal orchid growing conditions of the entire year. Dry air, low humidity and wide swings of day to night temperatures optimize both blooming and rooting of most orchids. In March, Nature gives orchidists growing outside a free sample of what life would be like with a covered green house. With little or no additional water falling from the sky and drying breezes acting like fans, we are in total control of our plants’ water needs. Now, we can water properly: very heavily, and allow the plants to dry thoroughly in the near desert air before the next heavy application of water.

The ideal growing conditions of March present a great opportunity to get our plants off to a superlative start on the new growing season. The virtuous among us, who have already re-potted their cattleyas and other sympodials as they have finished blooming across the winter, can smile serenely, assured of their place in orchid heaven. For us few reprobate it is still not too late to catch up with virtue. In addition to flowered-out plants, now is also the time to replant those genera which are breaking or ready to break their dormancy; i.e. catasetums, mormodes, calanthes and those Himalayan species that have finished flowering. Now is also an excellent time to re-pot those hard cane dendrobiums that need it, with the reminder that they really don’t like to be disturbed and relish their roots being crowded in the pot. For those commercially mass produced plants grown in peat based mixtures, repotting is necessary in any case as the peat mix will not last out the summer and will likely rot all the roots. Hopefully these will have rooted so thoroughly that the roots have formed a solid mass that can be shifted undisturbed to a new only slightly larger pot. Otherwise the roots will need to be washed clean and lightly trimmed. Rock, tree fern, coconut husk, charcoal/wood chip mixes are best replacement media for the long haul. All of these materials have a life expectancy of several years before they break down in South Florida wet humid summers.

Attention to fertilizer in March will pay high dividends later on. As many sympodial orchids are commencing their growth cycle, now is a good time to apply slow release fertilizer to last the season. The 13-13-13, 180 day formula marketed at Home Depot as ‘Dynamite’ (Nutri-cote in commercial sizes) is the best available. Its plastic coating is superior to others and relatively unaffected by heat, an especially important consideration in S. Florida. Applied now it will be exhausted by September when we want to slow our plants down in anticipation of bloom and dormancy. The wide temperature swings of March also maximize the effectiveness of high phosphorous ‘Bloom Booster’ fertilizer. The extra phosphorous in these formulas probably does not really stimulate flowers ( most likely the opposite) but does help rooting. Two applications a week apart will speed the rooting process. Return to regular 15-5-15 fertilizer weekly thereafter as the excess phosphorus in the “Bloom Booster” interferes with minor element absorption to an inordinate degree in our highly alkaline South Florida water.

Vandaceous orchids should be breaking vigorous new roots in March. This is the moment to top them if they have grown too tall and if they have three good roots on the top cutting. Conserving one or more leaves on the old plant’s stump will insure a bountiful production of offshoots. Sliding the knife or shears down the stem before making the horizontal cut usually preserves an extra set of leaves. Now is also the ideal time to remove and reset offshoots of vandas and ascocendas. Again take care each has three or more roots and be sure you tie them firmly in their new container until they have rooted solidly.

March is also the month for acclimatizing sun-loving plants to full sun. Vandas, dendrobiums and reed-stemmed epidendrums that have not been blooming as they should because they are in too deep shade can be gradually moved to more light. This is best done in two or three stages, moving the plants a short distance every few days and always keeping them with the same side orientated towards the sun. Without this gradual acclimatization, The bright clear sunlight of March can scorch even the most sun-loving of orchids.

The chief blot on the otherwise nearly ideal growing scenario of March is thrips. March is the month when we are asked most frequently “Why do my vanda flower spikes grow ½ inch and then die?” The answer, like the answer to so many problems with orchids in South Florida, is thrips. The hot dry weather of March favors thrips which are ubiquitous in our landscapes. The drought of March drives them from their homes in our lawns and shrubberies to seek the cool lush oasis of our orchid collections. Most orchidists recognize the symptoms of thrips on their flowers, :the silvered, sand blasted appearance and the withering of the flower parts. Many do not recognize the earlier symptoms which show up on the root tips of vandas and ascocendas as a pitted ring at the point where the green growing root tip is maturing into white. Left unchecked, this damage will cause the root tip to wither. When it re-starts growth, a brown ring remains. Orthene (acephate)is the chemical of choice for thrips because of its low toxicity and residual action. Knoxout and Malathion are recommended also by the Florida Department of Agriculture. A non-chemical solution is liquid dish soap applied at the rate of 2oz (6tbs) per gallon of water. Be sure to water the plants the day before applying soap and take care to drench the plants thoroughly, covering not only all the surfaces but penetrating into leaf axils and other nooks and crannies where the reclusive thrips loves to loiter. Root the thrips out of your collection and you will get the growing season off to a good start.

Motes Orchids 2/3/21 Motes Orchids 2/3/21

February in Your Orchid Collection

FEBRUARY CLIMATE DATA
Average high: 77.7
Average low: 60.7
Average mean: 69.1
Average rainfall: 2.07"

Despite the bloom on the avocados and the burgeoning new leaves on the live oaks, February is not spring in South Florida. Danger of freeze continues past mid month and frost can occur still into March. Even if the weather is balmy it’s too early to let down our guard or take down any protection we have mounted against the cold. The trend however is toward the positive as each lengthening day brings extra hours of warming sunshine to begin waking our plants from their long winter’s rest.

February characteristically brings a wide swing of day to night temperatures, ideal for spiking ascocendas and vandas but also wringing from the air heavy dews and dense fog. Whilst these add a romantic atmosphere to the South Florida landscape, Wuthering Heights is singularly devoid of snails and slugs (much less Botrytis). The silvery carpet of dew provides a silky path to our orchids for snails and slugs which can range far, under these favorable conditions. They are eager to make a nice meal of your Phalaenopsis leaves or the soft crowns of your vandas before they retire during the dry months of March and April only to dream of the fresh shoots of the sympodial orchids brought forth by the first rains of May. Now is the time to give them a rude awakening. Remember that snail bait is most effectively applied lightly (scatter the pellets every few feet) and frequently (every 7 to 10 days). Two or three applications should do the job.

The heavy fog which can cause condensation on leaves even under cover can also bring trouble. Botrytis is a fungus disease that can disfigure flowers with small black spots. Particularly apparent and annoying on white Phalaenopsis, Botrytis can ruin other flowers as well. Control is typically achieved in commercial greenhouses with fungicide in aerosol forms and by running fans to prevent condensation on the flowers. The latter option is also available to collectors. A small fan turned on the spiking and opened flowers at night will greatly alleviate the pressure of Botrytis. So will, to a degree, the application of soap which we suggested in January to control mites. Bicarbonate of soda, ordinary baking soda, at 1Tbs. per gal will help as well. Quaternary ammonium compounds (Physan, RD40, Consan, pool algicide) also give some control. Maintaining long lasting flowers like Phalaenopsis, dendrobiums and bi-foliate cattleyas in more perfect condition is well worth the effort. Having waited so long for the flowers we want to enjoy them as long as possible and they do all last longer in cool weather.

The lower overall temperatures of February call for less frequent and lighter applications of fertilizer as was the practice in January. If any reddening of the foliage persists another application of Epsom salts (1Tbs per gal), preferably in combination with Potassium nitrate, is called for; Nitrate nitrogen being more available to the plants under cooler conditions. If your resolve holds steady not to water (or above all) fertilize those Himalayan dendrobiums, your reward may shortly become evident in bursting flower spikes.

Like the avocados and the live oaks, many cattleyas and other sympodial orchids have bloomed and are just commencing new growth in February. Right after flowering is usually an excellent time for repotting from the plant’s perspective and the cool day time temperatures in the greenhouse are hospitable to the orchid grower as well. It’s still a bit early to re-basket vandas But an early start on the cattleyas will allow plenty of time and energy for those Spring chores which are right around the corner. With that thought setting out to secure a good supply of pots in anticipation of the potting season ahead is on February’s agenda.

Click here to purchase the new, updated, second edition of Florida Orchid Growing: Month by Month.

Motes Orchids 1/14/21 Motes Orchids 1/14/21

January in Your Orchid Collection

Average high: 76.5
Average low: 59.6
Average mean: 68.1
Average rainfall: 1.88"

January is somewhat like December but in reverse, with each succeeding day bringing longer hours of sunlight until days are long enough that afternoons return at the end of the month bringing extra sunshine to warm us after the extra sharp cold snaps. January, like December, is cold and dry, in fact even colder and drier. Dry is good, cold can be very bad. We need to accentuate the positive by especially careful watering in January. By keeping our plants as dry as possible and spacing our waterings as far apart as possible, we conserve our potential to use water to protect our plants from the cold, keeping our powder dry, as it were. In January water early, water thoroughly when you do and do so sparingly. The cooler overall temperatures of January are much less dehydrating even to plants which have received less water. remember, many of our orchids come from seasonally dry and cool climates not so different from South Florida. Many orchids are equipped to handle the drier cooler conditions of our January. A good strategy is to “top-up” the light watering that our plants receive with the passing showers that each successive cold front brings. This slight additional irrigation may prove to be all the watering that many genera need. Such parsimony, preserves the possibility of using water on truly cold nights to warm our plants.
Water is the only feasible source of heat available to plants grown in the open, under trees, in shade houses or on patios in South Florida. Ground water here (and in most of the rest of the world is about 63 F. (16C). Water out of municipal systems is not far different. On truly cold nights turning on the water can be of great benefit to our plants, provided that they have not been over-watered in the days and weeks preceding, thus inviting the ever present fungi to do more damage than the cold. For this reason as well, in general, orchids are better off dry until temperatures approach frost or freezing. The logic for maintaining plants dry is not only to minimize fungal problems but also because cold air is typically very dry air. If plants are wet in very dry and rapidly moving air say 10 or more MPH, evaporative cooling can take place, chilling our orchids further and faster than they would if dry. When the water goes on it needs to be in heavy volume and it needs to stay on to keep the plants thoroughly bathed in its warmth. Very still air on the other hand, presents a different danger as frost is possible at temperatures higher than is commonly realized. In calm air frost can form at higher elevations and settle in on plants while the surface temperature is only in the upper 30's. The best forecast for nights when the temperature will hover near 40 is a light wind of 2-5 miles per hour. This light wind mixes the warm air near the surface and draws warm from the earth. Clear, cloudless, still nights with bright shining stars elevate the spirit but harbingers frost.
Forecasts of temperatures below 40 F should stimulate us to action.
If it is not practical to bring all the Phalaenopsis, vandas and hard cane dendrobiums into the house or garage, think of using water to help protect them. Shade cloth or even patio screen hold in a surprising amount of heat like an lacy Mantilla. Under screen, a fine mist head attached to a hose and left running beneath the bench or plant rack will provide several degrees of additional warmth that will often sufficiently temper the chill and ward of any light frost settling in. Growers with swimming pools frequently turn on the recirculating pump to keep a supply of warm water near the pool’s surface where it can add heat to the ambient environment. A few degrees of warmth frequently makes all the difference to our sensitive orchids. In more open areas not protected by a permanent irrigation system, an oscillating sprinkler at the end of a garden hose is very effective. These are readily available at Home Depot and garden shops for a few dollars. On frosty nights, start the water at bedtime and let it run until the sun is up. The extra water once or twice in a month will do no harm to orchids that have been properly and judiciously watered the remainder of the month. In fact, these occasions present the opportunity to be sure that excess fertilizer salts have been leached from the pots and medium. A good work can be born of necessity!
Remember that Himalayan dendrobiums and ‘‘warm growing’’ Cymbidium hybrids will positively relish temperatures down to 32F and a light frost is just the ticket for great bloom. Keep the water off these!
In the drought of January, mites, which affect nearly all genera of orchids, continue to be a serious problem that will only get worse. They will reach a crescendo in March and April but January is a good time to scotch them. Paphiopedilum and other softy leaved genera are particularly susceptible but no genus is free of them. One theory on why deciduous genera such as Catasetum, Calanthe and others lose their leaves hypothesizes that this totally rids them of mites.
Being totally rid of mites is a good thing! Sometimes this is easier said than done because mites reproduce with such voluminous speed. Their life cycle from egg to reproductive adult being is as short as twelve days. In order to control mites one must achieve as total a kill of the population as possible. Total control can only be achieved with two successive sprays. After spraying for mites initially, one must spray again in 7 — 10 days. No single spray is totally effective in killing both adults and eggs and a second spraying is necessary to kill any survivors before they can reproduce. Oil as recommended in the December chapter at 1.5 oz per gal followed in7-10 days by soap at the rate of 2 oz per gallon is very effective. These treatments are also quite effective against scale and mealy bugs which thrive on drought as well. Be sure your plants are well watered the day before applying both oil and soap and be sure that you cover thoroughly all leaf surfaces especially the lower ones which are mites favorite hide outs.

For those who wish to be more aggressive, the University of Florida IFAS recommended chemicals for mite control are:
Avid 0.15 EC
Kelthane T/O
Mavarik Aquaflow
Talstar Flowable
Always follow label instructions for use. Any of the can be alternated with the soap or the oil in the 7-10 day cycle.
Controlling mites pays huge dividends! You’ll be surprised at the extra vigor your plants display.

Cold Watch
As cold is a major theme of this month, a review of some factors effecting temperatures in South Florida should be particularly valuable to new comers in the wide world of orchid growing.
   While we bask in the warm glow of a tourist board’s vision of winter, (made all the warmer by thoughts of our envious friends and relatives stuck in the northern snow and ice) we should be mindful that January can produce quite severe cold. The majority of hard freezes in Florida take place in January, and even short of that catastrophe, the month usually brings the coldest weather of the year. We need to keep a sharp eye on the weather reports while remembering that in our almost island of Florida a number of factors influence the severity of the cold which will impact us.
   First the shape of the cold front interacting with the shape of the peninsula. The weather that delights the tourist board and all of us while plunging most of the US into the throes of ice and snow usually result from particularly large, slow-moving masses of cold air that have spread across much of the continent before reaching Florida. Large broad masses of cold air that seep downward over a broad front also cover the Gulf of Mexico and the Atlantic as they progress southward. These tempering bodies of water bathe the cold to merely refreshingly brisk temperatures. More dangerous to our plants are the smaller, tighter, fast-moving fronts which plunge like a dagger of cold straight down the peninsula to the tropical heart of South Florida. Such fronts typically spawn the freezes and severe plant-damaging cold that is of the greatest concern to orchidists and other plant people. These Siberian Express fronts bring winds out of the Northwest that are un-influenced by the benign, protective bodies of water flanking the peninsula as they drive down the central landmass of Florida. When the winds from an approaching front start out from the southwest and move gradually to the northwest and then quickly to the north and northeast, we can expect cold nights and warm days that reasonably well-protected orchids not only tolerate but in some case actually relish. The more savage fast moving fronts where winds start in the Northwest and stay there are the ones to send us thinking of moving plants or providing additional heat.
   Wind direction is always critical in South Florida. Because of the peninsula’s decided eastward cant, winds from the north in much of South Florida are in fact relatively mild. North winds here are blowing across the warm Gulf Stream. The first shift to the northeast absolutely spells relief as the warm Atlantic has absorbed the cold.
   Wind speed is also important. Strong winds at low temperatures chill our plants more rapidly, exposing them to additional hours of chilling. “Wind chill factor” has no relevance to plants until the actual air temperature drops to a level unacceptable to the plant. After that, the more rapidly the plant itself’s temperature falls to that damaging level and the longer it stays there the worse the case. Wind speed enters the equation only if the final low temperature is below our plants’ tolerance. Wind breaks of vegetation or manmade are always to be sought. Native epiphytic orchids hide out in the most protected hammocks and sloughs. We can learn from them.
Dead, still air looms with another threat: radiational cooling which can allow frost generated at higher levels of the atmosphere to settle in on our plants even when the air at the surface is only in the upper 30's. These frosts typically occur when the front has passed leaving such low humidity that there is no moisture in the air to retain ground heat which radiates quickly into the cold reaches of space. Light winds of 2-5 miles an hour are our friends on these nights. They stir additional heat from the ground and keep the colder upper air from settling in.
   Relative humidity also has a profound effect on temperatures. Dry, clear air allows heat to radiate out into space. Those bright starry nights are beautiful but as Good King Wenceslas knew they are not necessarily our comforters. The best measure of the dryness of the air relative to cold is the dew point. When water vapor is wrung from the air an incredible amount of energy is released and the heat of transformation raises the air temperature a degree or two. Because of this phenomenon, the dew point is usually the closest measure of the coldest temperature that will be reached in the night. Particularly on still clear nights it should be monitored closely.
   Wind direction, wind speed, dew point — where does one find these on a chilly night? At the Florida Agricultural Weather Network (FAWN), a system of automated weather monitoring stations, as close as your computer. There will be a station near you. There are also several at points north of the nearest location that give data on conditions that are effecting areas through which the cold front is moving toward us. FAWN is updated every 15 minutes here. Bookmark it for something other than worrying to do on those cold nights