Growing Orchids: May in St. Augustine
Based on AOS monthly checklists by Robert Scully and Ned Nash & James Rose, adapted to St. Augustine by local growers
General Orchid Growing Tips
Summer is right around the corner. Now is the time to maximize growth and develop the plant strength and food reserves needed for good flower production. Larger plants typically produce bigger and better flowers than smaller ones so resist the urge to divide your plants just for the sake of having more plants. Recycle your clay or plastic pots but be sure to sterilize them first along with any wire products. Do not reuse potting mix or drainage material.
Get a head start on dividing cattleyas by severing the rhizome in whole or in part (at a point where you will have 3 to 5 pseudobulbs per division) with a sterile tool while the plant is still in the original pot. The new growths will emerge weeks later at which point you can finish repotting using a rhizome clip to secure the divisions. Continue feeding cattleyas with a dilute fertilizer solution with each watering and flush with fresh water monthly.
Finish repotting these elegant orchids if they are bursting out of the pot. If the medium is in good condition (just a year old), you may be able to move the plant from one container to another with the addition of a small amount of medium without disturbing the roots. Keep the pots moist and syringe the foliage frequently, particularly if you have moved the plant into brighter light.
This is the ideal month to complete repotting of your lady's slippers into a fresh terrestrial mix. Remove dead roots and keep as many growths together as practical. The single flowered types should be in shade though the multiflorals like more light. Keep root zone moisture levels high (though Brachypetalum types generally like drier conditions).
Repotting plants that have finished flowering is a priority. When you repot, remove the old inflorescence and eliminate all rotten or completely dehydrated roots and cut the roots back to about 2/3 the depth of the new pot. Remove also the dried bottom section of the old crown until you reach fresh tissue. Resume fertilizing when new roots become visible. Consider a spraying program with a recommended fungicide.
Some plants may need more room for root development. If your plant is in a basket, simply drop it into a larger size basket. If your plant has become top heavy and unsightly, cut away the top part of the plant as long as this section has three roots to sustain it and rebasket it being careful to secure it so roots will not be damaged in the wind. Keep the bottom section of the plant in the old basket as it will usually sprout keikis at the base and be well established by the end of the summer.