SHEATHS: Yellowing

Ailments Orchid Doctor

by Robert M. [Bert] Hamilton (Compiler)

Originally published in The Orchid Doctor in 1980 and 1988

Posted by Sys Admin almost 8 years ago.

Article Blog   Article Index
Causes are not fully known, although ethylene can be suspected; some plants produce sheaths which yellow than go brown before the buds are initiated and they still flower normally. A82-122
Share on Social Media:  
Log in to Add a Comment

More The Orchid Doctor Articles under the Heading Sheaths

Sheaths Comments
SHEATHS: Blind On cattleyas are caused by insufficient light; hang them up close to the roof of the greenhouse. ODA72-134 0
SHEATHS: Browning C. skinneri sheaths naturally turn brown; but as it occurs more often in winter, poor light and ventilation either too dry or too humid could cause it; also too much water during the rest period; or the plant is just too plain weak to flower. OD88-9 0
SHEATHS: Bud On cattleya browning and dying off of sheaths is not likely to be caused by ethylene which would require a high concentration to cause it; most common cause in not known; to save the flowers remove the sheaths when they are yellowing. A77-922Yellowing or rotting of sheaths is caused by some factor unknown; if sheaths dry after yellowing, the buds inside should develop normally; remove early. A67-572; A80-513 0
SHEATHS: Buds Appear with No Sheath On cattleyas this is not unusual; not a disease, but characteristic. A70-631 0
SHEATHS: Buds Die Inside The cause may be dry rot or soft rot; after the yellowing, dryness will not affect normal development of buds; rotting and browning should be avoided by removal of the sheath; directions and illus. of removal. AH58 0
SHEATHS: Cattleyas Buds rotting inside can be caused by an accumulation of moisture in the sheath; caused by excessive watering, high humidity or rapid temperature change; do not overwater; cut off the tip. F77-16Do not mature in Louisiana; flower bud formation is influenced by length of day plus night temperature which can be too high in Louisiana; perhaps lighting left on in the growing area. A76-1007Drying of sheaths is common on winter and spring bloomers; remove them when they begin to yellow by tearing strips of the sheath downwards carefully to the pseudobulb, to let the buds develop; moisture and condensation in the dying sheath causes bud loss. A85-435No sheaths at all are produced; the cause in not known. A76-115; stimulate with good light and fertilizing. A80-630They appear but produce no blooms; the cause may be excessive fertilizing; remove the sheaths. A69-424; A75-1090They turn black and withered mostly because of water standing in the leaf-blade where the sheath begins. A83-24They turn... 0
SHEATHS: Double It is not uncommon for one sheath to form inside another on cattleyas; flowers develop properly; remove any yellow outer sheaths. A72-151; A76-1007; OD73-2On cattleyas; C.labiata or its hybrids normally have a double sheath; it should flower in the fall. OD73-2 0
SHEATHS: Dry It is a normal condition with Cattleya mossiae, and its hybrids and some other cattleyas. OD73-2 0
SHEATHS: Growth Is Poor and After Starting They Turn Dry or Brown The cause is not fully known; may be caused by air pollution or poor health, or not enough light; remove the sheaths, the buds will usually bloom. A76-795 0
SHEATHS: Infection, Bacterial It occurs particularly in hot, humid climates; caused by Pseudomonas bacteria; Physan 20 provides partial control; use it at 1 cc. per gal. of water as spray. A74-780+ 0
SHEATHS: Removal Effect on Buds Removal of the sheath does no harm but the bud stems may be weakened. A72-55 0
SHEATHS: Rotting Caused by Water Apparently water collecting around the base of the sheath can rot both sheath and buds within; illus. A77-436 0
SHEATHS: Sequence of Growth The sheath develops along with the new pseudobulb growth. A63-478 0
SHEATHS: Within Sheaths In cat tleyas a sheath growth inside another sheath is a heritage from Cattleya labiata which does it most frequently; why? A87-616 0
SHEATHS: Yellowing on Dozens of Apparently Healthy Plants The primary cause is not known; it is relatively normal on Cattleya mossiae and some hybrids; some may brown, soften and kill the buds; remove such. A74-34 0

New Topics

  1. James W McCully asked question How to read archived articles ? in category General Discussion
  2. David George asked question recently purchased orchid - what to expect in category General Discussion
  3. Danielle Carbonneau asked question phalaenopsis, dendrochum and Odontoglossum in category Phalaenopsis
  4. Nicholas Filannino asked question Phalaenopsis William Kistler? in category General Discussion
  5. Mark Farran asked question How to open and read articles listed in category General Discussion
Ask a Question

Start a Topic

New Comments

  1. Louis Wilson commented on member plant E. alata f. alba by Louis Wilson
  2. Julie Ellner commented on member plant Phal. amabilis var. formosanum by Vickie Seibert
  3. Julie Ellner commented on member plant Rlc. Green Dragoon 'Mendenhall' by Jeanne Uzar Hudson
  4. Danielle Carbonneau commented on member plant Ons. Catatante 'Los Roble' by Henry Shaw
  5. Barry J Silver commented on orchid Lyon. SunCoast Pink Passion
  6. Carol Holdren commented on topic "Phalaenopsis William Kistler?" by Nicholas Filannino
  7. Carol Holdren commented on orchid Colm. Eric Gabriel Heines
  8. Carol Holdren commented on topic "Cattleya little susie" by Juliann Eckhard
  9. Carol Holdren commented on member plant Bc. Morning Glory by Chris Siolo
  10. R .Benson commented on member plant Kir. New Hybrid (Fred Clarke) SVO9831 by R .Benson
  11. Carol Holdren commented on topic "Blooming Stenglottis Venus “jamboree “" by John Urey
  12. Jeanne Uzar Hudson commented on member plant Lc. Canhamiana var. coerulea 'Cobalt' by Jeanne Uzar Hudson
  13. Jeanne Uzar Hudson commented on member plant Sns. gemmata by Jeanne Uzar Hudson
  14. Stefan Neher commented on topic "Orchid roots .com site?" by Mary Lane
  15. Kevin Barry commented on member plant Bul. Tammie Sue Pernas by Tony Pernas
  16. Linda Hartman commented on member plant Ctt. Final Blue by Linda Hartman
  17. Kevin Bergeson commented on member plant Paph. rothschildianum by Kevin Bergeson
  18. Carol Holdren commented on topic "recently purchased orchid shows unstoppable roots " by David George
  19. Michael Makio commented on orchid V. Beatrice Makio
  20. Carol Holdren commented on topic "shorter stem with less vigorous blooms" by katherine mott