Orchid Ailments – Bud Blast

It can be heartbreaking to watch helplessly because long-awaited orchid buds brown, die and fall instead of becoming those much-anticipated flowers. Bud blast, when buds become drier and smaller and finally fall from an otherwise healthy plant, may occur through any of a number of causes. Buds are the most sensitive part of an orchid, and are easily affected by inappropriate conditions in the growing environment. Cattleyas, Phalaenopsis and Dendrobiums seem particularly suffer from this problem. The most frequent reasons for this are as follows.

Water

Underwatering or overwatering is a happening often cause of bud blast. If a plant becomes too dry, it may withdraw moisture from buds as a survival mechanism. Overwatering can damage the orchid’s root system, with the end result being a lack of water to the plant. As with underwatering, when the plant cannot absorb enough quantities of water, it will withdraw water from the buds, bringing about their ending. Budding Cattleyas (Thai orchids) are particularly easily affected to overwatering, which can cause buds to blacken and die while still in their protective covering. Water that is allowed to sit on buds or in bud protective covering provides the perfect conditions for fungi and bacterial growth, generating rots that will blast buds. Watering with cold water can shock a plant, causing bud drop.

Temperature

Temperature extremes or quick temperature changes are often a criminal in bud blast. If a budding orchid receives cold air from a window, an air conditioning or heating vent, or even a rush of air from a hot oven, it may drop buds. Similarly, buds may be damaged when exposed to temperature variations that occur when taking a plant in and from the car or outside during hot or cold weather, bringing plants back in a hot home after a summer outdoors, or extreme temperatures that were  caused by running the heater or air conditioning for part of the day.

Atmosphere

Orchid buds are easily affected to fumes from paint, natural gas leaks and other chemicals. Once pollinated, flowers generate methane gas, causing them to collapse and saving energy for seed production. Methane or ethylene gas from other sources may also make bud or flower collapse. Ethylene gas produce by ripening fruit; gas leaks; inefficient burning of gas stoves or heaters; engine exhaust; cigarette, cigar or pipe smoke; open fires; smog or air pollution can also cause bud blast and age and change appearance of open flowers.

Light

If lighting available to its developing buds is insufficient, an orchid won’t flowers properly. Lighting is the one to take care of. Low lighting can cause buds to stop its development. Too much light can inadvertently be troublesome, as the developing buds can overheat and desiccate.

Chemical Damage

Fertilizer, fungicide or pesticide used at dosages above a plant’s tolerance or in a way inconsistent with manufacturer’s instructions may destroy buds, causing them to fall.

Humidity

Developing buds need high humidity. If their conditions are too dry, or the ambient humidity varies a great deal, buds may be unfavorably affected and fall.

Insects

Aphids and thrips can cause bud blast. These insects eat flowers and flower buds, sucking the plant juices. The buds of infested plants is unsuccessful to develop properly, falling from the plant or opening to damaged and deformed flowers. Diazinon or Malathion can be used to control Thrips. Aphid control often involves not only eliminating the aphids themselves, but also the ants that keep them. Insecticidal sprays and sugar-based ant traps are recommended. For a few aphids, dab with a cotton sponge soaked in rubbing alcohol are recommended. Other means of control include insecticidal soaps, horticultural oils (Neem or Sunspray), growth regulators and chitin inhibitors (Enstar II), Pyrethrum-based insecticidal sprays, stronger insecticides (Malathion), and systemic insecticides (Orthene, Shield).

Repeat any treatment method twice after the first application at seven- to ten-day intervals to kill successive generations. Test new controls on a small population of plants before widespread use. When using insecticides, check labels carefully to ensure the insecticide works against the particular pest and that it is officially accepted for use on orchids. Always use any chemical strictly according to manufacturer’s instructions.

Genetics

Sometimes, even under ideal cultural conditions, an orchid will constantly abort buds. There may be a genetic mutation responsible for its inability to produce viable blooms. In this case the plant should be discarded.