Orchid Culture - 2023 Questions & Answers

Keiki on Unhealthy Dendrobium

Q. I have a keiki growing on this dendrobium, the roots are healthy but the plant doesn’t look so good. Any thoughts greatly appreciated.
A. The roots need to be a little longer, at least 2 inches long, before you separate the keiki from the mother plant. When you repot, put it in a pot that seems too small, no bigger than a 2 or 3 inch pot. Dendrobium canes grow very closely together, and a small pot will accommodate the plant for the next 3 years or so. The pot the dendrobium is in now is probably too large for the plant. If you want to encourage faster root growth on the keiki, you can air layer it with sphagnum moss, wrap some damp sphagnum around the roots and tie it up with some mesh or pantyhose to hold everything in place.   (Feb-23)

Growing Indoors Under Lights

Q. Whatever this is, it is going through my collection. I am growing inside under lights. My first thought was thrips, so I sprayed with Captain Jack's Dead bug because it has spinosad. Today, I sprayed with Aliette. Suggestions, please.
A. The gray stippling and brown wounds look like the damage caused by mites. Do you have a loupe or magnifier so you can check for mites? Mites are a real problem for indoor growers, because they thrive indoors in the low humidity. They are arachnids, so most insecticides won't kill them. Avid is a good miticide if you have it. Or you can use one of the home cures, scroll down to the mites section for some ideas.   (Feb-23)

Top Heavy Vanda

Q. What can you do with a tall vanda that has roots at the base and none above that? If you just "top" it, and there are no roots presently, will it just die? Do you have any recommendations on how to stimulate roots up higher for the top section to be separate.
A. That vanda looks nice and healthy. You might try spraying seaweed or a stronger root stimulator in the leaf axils where you'd like the roots to form, say weekly. Or, wrap sphagnum moss with panty hose where you want the roots. (Feb-23)

Keikis on Cycnoches

Q. This Cycnoches Topaz Grande is my pride and joy, but it obviously thinks it’s dying as do I. One cane rotted off but the others seem to be quite firm. Do I just leave it do its own thing or do I somehow remove the keikis?
A. If your plants have time left in the growing cycle, I would cut the bulbs about half way between the nodes that carry the keikis and pot them up in small (2 to 3 inch) pots in good sphagnum moss and let them grow til dormancy hits, the nutrients in the pseudobulb will continue to nourish the keikis until their roots grow into the moss. Another alternative would be to get a shallow bulb pan with long fibered sphagnum moss and just bury the pseudobulbs half way into the moss so the keiki roots can grow into it. The bulbs will ultimately rot and you can pull them out while the keikis continue to grow. The keikis may continue growing through the winter, or they may go dormant. If most of your other plants have entered dormancy, it may be better to leave the keikis on until next spring.   (Jan-23)

Hard, Clear Bubbles on Phal Leaves

Q. There are hard, clear bubble shapes on my phal leaves. It doesn’t look like an insect. What could it be?
A. That's edema, like a water blister. It happens when you water late in the day when the air cools or the skies turn gray, so transpiration slows down and the water needs to be shed from the leaf so it forms these little blisters. It won't harm the plant. Here's a link to more information. (Jan-23)

Color Break on Cattleya

Q. Do you think this is virused? Where can I buy some test strips?
A. That looks like a nasty case of color break caused by Odontoglossum Ringspot virus (ORSV). Sometimes you can join a group that is ordering the test strips from Taiwan, or you can order from Agdia in groups of 5 to 25. Such a shame!   (Jan-23)