Motes Orchids 5/5/17 Motes Orchids 5/5/17

May in Your Orchid Collection

May Climate Data

Average high: 87.2
Average low: 72
Average mean: 79.6
Average rainfall: 5.52"

May is a month of transition in South Florida. Early in the month we can expect the driest weather of the year. Because of the clarity of the air and lack of cloud cover, temperatures rise rapidly in the late morning and can reach the upper eighties or nineties by mid afternoon before cooling substantially in late afternoon. Fortunately, over night radiant cooling rapidly dissipates the previous day’s heat. May mornings are a delight, the wise orchidist rises early to enjoy them and to finish his chores before the heat sets in. Chief of these should be extensive dragging of hoses.

May’s wide temperature swings and dry air suit our orchids to a tee. New growths on sympodial orchids are developing apace and by continuing the careful watering practices of April (i.e drenching them thoroughly with repeated applications of water to saturate their roots and potting media, then allowing them to dry to nearly ‘hard’ dry) we can launch them into the summer in vigorous, disease-free growth. Remember, this saturation can only be achieved with two or more soakings to the point of runoff spaced a few minutes apart. Merely holding the water on the plant extra long will not suffice. The water needs to slowly soak into the roots and media. Test the weight of a “benchmark” plant to be satisfied that it is sufficiently heavy to be totally soaked. The arid air of early May will quickly dry the foliage but the roots can draw on the deep reservoir of water that you have provided with this careful, complete watering.

With the increased heat and light of May we do not want to put our orchids on too lean a diet. Fertilize with up to 2 tsp. of 15-5-15 per gal of water every week or so. Alternating with Epsom salts and potassium nitrate at 1 tbs. each per gal. is still a best practice during May. Always substitute fertilizer for a watering and apply like the water in two doses to the point of saturation. Never follow the widely stated but antiquated advice to “water before fertilizing”. It’s a receipt for over watering without any basis in logic or science, Now is also a good time to apply a soluble trace or micro element fertilizer. Follow the dilution rates on the package as mixtures and strengths differ. You can apply this in conjunction with the Epsom salts/potassium nitrate but never with the 15-5-15, 20-20-20 or any other fertilizer containing phosphorus. In South Florida’s highly alkaline water the phosphorus interacts with the other metallic elements, reducing the effectiveness of the trace elements. Potassium nitrate, 13-0-46, is the perfect companion to minor elements because it not only lacks phosphorus which would hinder the absorption of the trace elements but the nitrate nitrogen seems to enhance their uptake.

May is still prime time for re-potting. With cattleyas, dendrobiums and other sympodials, the virtuous among us have long since finished this labor of love, but the majority of us are faced with the moral dilemma of doing the potting now or waiting until next year with the pseudo bulbs of our plants overhanging their pots and proclaiming to the world our sloth. The one instance in which this dilemma must be resolved absolutely in favor of the plant, is when the media has broken down in the pot. This condition will encourage root rot to become stem rot which will pursue the rhizome even into those over arching bulbs. If in doubt, give the media the “nose test”. A pinch of media taken from below the surface of the pot should smell “sweet”. A sour smell or the odor of a pond bottom indicates media that is broken down and must be replaced as soon as possible.

The case in which this is almost universally true is with plants potted in sphagnum moss. Sphagnum simply will not last beyond one year (even under cover) in South Florida. As the vast majority of commercially produced Phalaenopsis are now grown in sphagnum, recently acquired plants MUST be re-potted annually. As most Phals. will be finishing their flowers, now is a good time to get them right for the new year’s growth. When repotting, one can, of course, choose a more durable media; rock, red wood chips or various mixtures and avoid this annual ritual. Choosing a more durable media will entail modifying one’s watering schedule to accommodate the faster draining, quicker drying qualities of these harder substances.

May is a great month for re-setting vandaceous orchids whose baskets have deteriorated or that have grown too tall to be easily managed. keikies (off-shoots) can be most safely removed now. In both cases choose the most durable containers for the plants so they need not be disturbed for years. Teak or other hard wood baskets and clay pots last longest. Above all make amply sure that the plants are firmly fixed in their lodging. Vandaceous orchids, above all others, are intolerant of being loosely set. The very height of these plants act as a lever to keep them rocking unless we anchor them securely until their new roots affix themselves to the new containers. Stake and tie them securely until their abundant roots take over. Unsightly staking can then be removed.

As we bask, lulled into complacency by the nearly ideal weather of early May, Summer sometimes surprises us. Toward the middle or end of May, the weather in South Florida literally undergoes a sea change. The large continental weather patterns which have dominated our weather through the winter and early Spring give way to the tropics and the prevailing south easterly trade winds return us to the interaction of Gulf Stream and peninsular with its characteristic afternoon thunder showers. Although lacking the clockwork consistency of June, the rains have come and we must be prepared for them.

The relentless and increasing crescendo of rain will, by summer’s end, tip the balance in favor of the ubiquitous fungi lurking to attack our orchids. The time to scotch their plans is now; an ounce of prevention is worth a pound of cure.

Leaving the taxonomic niceties to the experts, fungi which attack orchids in Florida fall into two broad classes; the leaf spotting types (Cercospora and Phyllosticata) and the soft rots (Pythium and Phytophthora). Fortunately, for modern orchidists, excellent systemic fungicides exist for both types. While these chemicals are no substitute for good cultural practices, i.e. adequate spacing, brisk air movement; the strongest possible light combined with careful watering, fungicides provide the edge to approach near total control of most fungal diseases even in their ancestral home, South Florida. May is a good time to take stock of the collection and see which plants are overgrown and need more space or perhaps even re-potting. The increase in air circulation is well worth the effort. Trimming shade trees and moving plants to brighter locations are also good strategies for May. May is also a good time to consider a preventative spray program before disease has a chance to get the upper hand in our collections. An ounce of prevention begins now.

Leaf spotting fungi are symptomatic of poor air circulation and inadequate light but even under good growing conditions are rarely entirely absent from orchids in South Florida. This near inevitability results because the same diseases also afflict so many other tropical plants in our gardens. Under the battering of the heavy and sustained rains of our wet season, the most minor of problems can occasionally blossom quickly into a major epidemic. Thiophanate methyl (Cleary’s 3336, Domain, Fungo) is the proven and recommended systemic fungicide to control leaf spotting. It is even more effective when combined with Mancozeb (Manzate or Dithane M45.) Two pre-packaged combinations are available; (Duosan, and Tops MZ ). Always follow label recommendations for rate of application.

To be truly effective, Thiophanate methyl should be applied initially early in the growing season (IE now!), then again in two weeks and then every 5-6 weeks thereafter across the rainy season. Faithfully followed, this regimen will control nearly all leaf spotting fungus, including the dreaded ‘Thai crud’: Phyllostictina capitalense. A spreader sticker enhances the effectiveness of the fungicide by holding it on the plant through the hardest rain.

The soft black rot of sympodial orchids and crown rot in vandas are caused by two different organisms i.e Pythium and Phytophthora although in effect they are indistinguishable. Control of these diseases necessitates different chemicals from those used on the leaf spotting diseases. Etridiazole (Truban) has long been used. For the amateur it is readily available in combination with Thiophanate Methyl (the recommended chemical for leaf spotting) in the formulation Banrot. Applied in the same manner suggested above for Thiophanate methyl to control leaf spotting fungi, this pre-packaged combination should be adequate for most circumstances and control crown rot as well. If problems persist two other systemics give excellent control: Aliette (Fosetyl-aluminum) and Subdue 2E (metalaxyl).

All chemicals should only be applied at the rates and according to the label instructions. If in doubt about whether to or how to apply a pesticide always call your County Agricultural Agent at 305 248 3311 for advice.

Motes Orchids 4/6/17 Motes Orchids 4/6/17

April in Your Orchid Collection

Looking for this month's culture tips? Click here for April in Your Orchid Collection.

Motes Orchids 2/26/17 Motes Orchids 2/26/17

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 2/6/17 Motes Orchids 2/6/17

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.