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Root tips turn black

  Q: On my orchids, if the new roots do not enter the potting media when 2-3 inches long, the tip turns brown/black and stops growing. Could this be due to not misting the plant often enough?   A: Extremely low humidity (<25%) usually causes the symptoms you describe. Frequent misting with high-quality water can […]

Charcoal vs bark

  Q: Are cultural requirements different for charcoal than for fiber and bark? A: You can grow epiphytic orchids in any medium except soil as long as you can adjust your watering and fertilizer practices to the new medium. Water any medium thoroughly and then not again until the medium is dry. The difference in […]

Flower color

  Q: Does geographical area affect the color of blossoms, specially reds? I live in Hawaii. All locally hybridized reds seem to be plum or bluish red and same plants from California growers are cherry red. A: At high night temperatures flower color is less intense because the sugar is used for respiration and anthocyanin […]

Delaying blooming of orchids

  Q: Is there any way to hasten or delay flower spike elongation and subsequent flowering, so as to time flowering to coincide with orchid shows? A: Temperature and light control can be used. Higher temperatures hasten while lower temperatures retard flowering. Many people try to hold plants by lowering greenhouse temperatures without shading, and […]

Orchids with no root

Q: What is the best way to re-root orchids that have lost their roots for one reason or another? A: A traditional wisdom dictates that plants can be encouraged to root by providing a moist and warm atmosphere while keeping the medium on the dry side. This enables the plant to remain turgid (not wilted) […]

Cattleya buds turn black

  Q: One of my cattleya developed a sheath, whereupon I discovered two buds inside which were completely black. Please comment!   A: This is rather common. You should examine sheaths regularly, and when shadows of the buds appear within, you can cut the top 1/2″ off the sheath. This will allow the buds come […]

New Cattleya growths turn black

    Q: New growths on my Cattleya orchids turn black and die or never grow to full size. The mature growths are wrinkled. I would appreciate any suggestion. A: From your description, several problems can be inferred. The blackening of the new growths on orchids or their failure to mature usually indicates starvation of […]

White residue from watering

  Q: With what can I clean the leaves of my orchids to remove white residue left from watering? A: The white residue is probably calcium from your water supply and best can be avoid by keeping the water off the foliage. If that is not possible you can treat your water to reduce the […]

Add fungicide to water

Q: I water by immersion of the entire pot into water containing weak fertilizer. Can I add a bactericide like Physan 20 to the regular watering? If so, at what concentration? A: I have been doing exactly like what you describe for a couple of years. It is to prevent mold and algae growth inside […]

Whitish mold on bark

Q: Quite a large amount of bark enclosed in a plastic bag for about a year is covered with a whitish mold. Would this be harmful to my orchids. Would a fungicide drench be wise such as Physan 20? A: It looks like your bag of bark was wet when filled, hence the fungus growth. […]

Weak cymbidium leaves

  Q: My cymbidiums need help. The new leaves cannot support themselves. They fold over about halfway along the length of the leaf. This fold turns brown and hard. Some of the leaves have a long split running lengthwise down the center of the leaf. A: From information provided my best guess is that you […]

Wrinkled bulbs

Q: I am growing cattleyas in a window greenhouse. Many leaves and bulbs have started to become wrinkled and creased where they originally were smooth. What causes this? A: Wrinkled leaves and bulbs are a sign of dehydration. The plants are not receiving enough water. This can be because of low humidity in the home, […]

Black spots on orchid flowers

Q: I placed a large flowering cattleya on a shaded, covered patio. Flowers last a long time but developed small black spots all over the blooms. What caused this? A: Petal blight, caused by a Boltrylis fungal species, is common during cool, damp weather where there is inadequate air circulation. Phalaenopsis and Catttleya-like flowers are […]

Wood basket repot

    Q: I have a vigorous bifoliate Cattelya orchid that is outgrowing its wood basket. I am unsure how to repot it because its roots woven through and around the basket, making it impossible to remove without severe root loss. The medium and the basket are still in good shape. Could I just pot […]

Problem with small snails

    Q: I have been having trouble with small snails (approximately 2mm) eating new roots on orchids grown in my house. What can I use to get rid of them? I have tried some snail baits, that I bought from Home Depot, several times without success.   A: Small snails are often difficult to […]

My orchids refuse to bloom

Q: I have several Cattleya and Oncidium orchids which refuse to bloom. They are outgrowing 6″ pots and are in heated greenhouse with a 55F minimum temperature. I am sure they receive enough light because they are right next too some Brassavola digbyana and Brassidium, which bloom profusely. I feed very two weeks with a […]

Light effect on Cymbidium orchids

    Q: A neighbor has put up a vapor light on his three-story house that stays on all night. My cymbidiums are 100 feet away, yet it is not dark. Will this cause problems in their blooming?   A: Cymbidiums are temperature-responders as far as flowering is concerned. I do not know of any […]

Cattleya new growth

.     Q: When I purchase a new Cattleya the next new growth that is produced is almost always smaller. It is usually smaller and not as broad. These new plants rarely flower on these smaller growths. Could the problem be associated with gross underfertilization or excessive sunlight?     A: Diminishing size of pseudobulbs […]

Black rot

  Q: What are the symptoms of black rot? What causes black rot and how do I deal with it? Is it contagious   A: There are two black rots, one cool weather type and one warm-weather form, each caused by a different blade. They are contagious and can be spread. The warm-weather type is […]

Phalaenopsis gigantea culture

(Photo courtesy of Ed Merkle)   Q: Does Phalaenopsis gigantea have different growing requirements from other phalaenopsis? I have had mine for about six months on a light-cart. It has not grown or spiked. Its leaves are a very pale silvery green.   A:  Pale, silvery green leaves are typical for this species, which must […]

Cymbidium bud drop

  Q: I bought a new cymbidium a couple of months ago. It had two spikes and many buds and the buds almost reached opening size. Then during a month, one at a time, the buds yellowed and dropped. Why? One of them struggled to open with curled sepals.     A: A number of […]

Vanilla bean

  Q: Which orchid is responsible for producing the vanilla bean?   A: The fruit of vanilla is botanically called a capsule, although we often refer to it as a bean. Many species of vanilla produce vanillin, the active ingredient in vanilla, but Vanilla planifolia yields the highest quality flavoring and is the on most […]