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. F77-16

Do 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. A76-1007

Drying 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. A85-435

No sheaths at all are produced; the cause in not known. A76-115; stimulate with good light and fertilizing. A80-630

They appear but produce no blooms; the cause may be excessive fertilizing; remove the sheaths. A69-424; A75-1090

They turn black and withered mostly because of water standing in the leaf-blade where the sheath begins. A83-24

They turn yellow and wither because their growth is usually in the spring and one type flowers without hesitation, but the other waits until late fall or early spring next year by which time the sheaths are often dry and papery. A83-24

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: 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 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	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

Sheaths

Comments

SHEATHS: Blind On cattleyas are caused by insufficient light; hang them up close to the roof of the greenhouse. ODA72-134

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

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

SHEATHS: Buds Appear with No Sheath On cattleyas this is not unusual; not a disease, but characteristic. A70-631

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

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

SHEATHS: Dry It is a normal condition with Cattleya mossiae, and its hybrids and some other cattleyas. OD73-2

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

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+

SHEATHS: Removal Effect on Buds Removal of the sheath does no harm but the bud stems may be weakened. A72-55

SHEATHS: Rotting Caused by Water Apparently water collecting around the base of the sheath can rot both sheath and buds within; illus. A77-436

SHEATHS: Sequence of Growth The sheath develops along with the new pseudobulb growth. A63-478

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

SHEATHS: Yellowing 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

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

SHEATHS: Cattleyas

by Robert M. [Bert] Hamilton (Compiler)

Originally published in The Orchid Doctor in 1980 and 1988

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