1. I have a Cattleya orchid which I have been attempting to rebloom for 5 years. Every summer a flower spike shoots up. The flower pod opens and the bud attempts to open but it turns black and withers. Help please?
2. How can I get a Kalanchoe plant to rebloom?
Question No 1.
If your long awaited orchid buds turn brown, die and drop instead of flowering, it sounds like your plant may have “bud blast”, when buds wither and fall from an otherwise healthy plant. Buds are the most sensitive part of an orchid, and are easily affected by unsuitable conditions in the growing environment. Cattleya orchids seem particularly susceptible to this problem. The most frequent reasons for this are as follows:
Under watering or over watering is a common cause of bud blast. Budding Cattleyas are particularly sensitive to overwatering, which can cause buds to blacken and die while still in their sheath. Water that is allowed to sit on buds or in bud sheaths provides the perfect environment for fungi and bacterial growth, generating rots that will blast buds. Watering with cold water can also shock the plant and cause bud drop so room temperature water is advised.
If a budding orchid receives drafts from a window, an air conditioning unit, a heating vent, or even a rush of air from a hot oven, it may drop buds.
When your plant is in bud, keep it away from direct sunlight. After the previous flowers have faded and died, cut off the flower stem and pod-like sheath down to the axil of the leaf, but don’t cut the leaf. It should flower again next year at the same time. In order to bloom again, it must develop new growth (stem or pseudo bulb) from which the flower will appear. Most cattleya produce one new flush of growth annually, and each new pseudo bulb should produce flowers that same growing season, often in late summer or winter. When a plant goes into flower, reduce watering to avoid accidentally rotting the flowers.
You can find further detailed information about problems with orchids on the The American Orchid Society website, see link below:
You might also want to read the Toronto Master Gardeners guide to Growing Orchids. Hopefully this will give you a chance to review, and employ some of the basic methods, and practices related to successfully raising orchids, and bringing them to bloom. See the link below:
Question No. 2.
In order to get your Kalanchoe plant to rebloom, cut off what is left of the flowering heads. Let the plant rest and water it minimally. Reduce watering as daylight hours are shorter and only water enough to keep the leaves from shrivelling up. Keep it in a sunny spot and away from cold drafts. It should re-flower again next spring which is the natural time for it to bloom. You can use half-strength water soluble all purpose fertilizer once a month from spring until fall.
For additional information on caring for cacti & succulents, you should take a look at the Toronto Master Gardeners Guide on the topic, find the link below: