April is the busiest time of the year for orchid hobbyists and commercial nurseries alike, because most orchids are beginning their annual growth cycle. Fertilizing now will make a difference later when plants put out new growths and flowers. Hobbyists using Nutricote or Dynamite, 6-month release form, should apply it now. By the time cattleyas and most dendrobiums are ready for a rest, the release of fertilizer from these products ends. Phals and other continuous growers will require this type of fertilizer again after 6 months.
Standard Phalaenopsis, those with large flowers and no fragrance, should be in peak flower now. If you grow indoors, your standard phals’ flowers may be just beginning to open if they did not experience an early fall cooling period. If this happened to you, remember next year to cool them down at night to 60 F for 7-10 days to initiate flower spikes. For now, enjoy the phal flowers, which should last into late spring if the plants are healthy and you get them a good supply of humidity during the dry spring days. If your phals begin to drop flowers while still opening new ones, it may signal low humidity or an inadequate root system. A healthy phal will put out new roots and new leaves even while flowering.
If you plan to repot a phal, it is best to remove the spike when the last buds have opened. Remove the old medium and any dead roots and place into a pot in which the roots fit with just a little extra room. It is always better to under pot than over pot. If your phal has lots of leaves, but few roots, pot into what may seem to be too small a pot. Once repotted, place the pot into a larger clay pot for support. If the plant is healthy, roots will quickly emerge and grow out the bottom of the small pot onto the clay pot, which is fine. This is preferable to over-potting and losing your roots and likely the whole orchid.
Most cattleya hybrids can safely be repotted now, but it is always best if repotting is done just when the plant is initiating new growth. There is no way to save most of the old roots that are attached to the pot, so most growers remove the bottom third of the root mass.
Most orchids that die right after repotting do not die from repotting itself, but from infections that occur during the process. Moist, damaged roots are easily invaded by both bacteria and fungi during this time. Some hobbyists cut the roots, tie a label on the plant and let it sit with lots of air movement in a shady, but well-lit location until new roots appear. This allows any wounds to heal and ensures that the cattleya is ready to grow when potted. Why waste a pot and medium if the orchid is not going to grow? Other growers do the same thing, by setting the orchid in a pot without medium until new growth is initiated.
Commercial growers often do not worry about infections and, instead, use anti-bacterial and anti-fungal drenches. Others buy cinnamon powder in bulk and sprinkle it on the roots to kill bacteria and fungi. The cattleya is then potted in dry medium and left un-watered for a week or so.
One of the hardest orchids to repot is a vanda. Most experienced growers never repot members of this group, but just hang them up and let them grow. Often the original container disappears amid the roots. Miniature versions of the vanda group, notably hybrids with Neofinitia, are now being grown for indoor hobbyists. These grow well under lights, but are sold in dense media, which requires repotting. The roots of this type of vandaceous orchid still like to dry out more than most orchids, but will tolerate more moisture as long as there is either good air movement around roots and/or the medium is acidic. New Zealand sphagnum is a favorite for this type of orchid and is used very effectively by the best growers in Japan.
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