SO Gardening July 15
Dear Orchid Doc:
The leaves and stems of my Miltonia seem very healthy, but while the plant blossoms I’ve noticed that the blooms never open fully before they fall off. Is there anything that I can do?
MD
Dear MD:
Miltonia orchids are cool-growing plants and as such temperature is critical. Unless kept under 26 degrees C they may not flower at all. But seeing as your plant blooms, it sounds as if you have a humidity problem. The humidity for Miltonias must be at least 70 per cent because of the plants’ need for abundant water, in the area where you house the plant, try and achieve this. You may also try spritzing the buds as they start opening.
Dear Orchid Doc:
Are there any disadvantages of growing orchids with peat?
Kelly
Dear Kelly:
This dark brown soil-like substance, made up of decomposed plants, is popularly used by orchid growers. Peat mixtures can hold quite a large volume of moisture and generally promote good aeration. However, because the mixtures can sop up high amounts of water, the medium stays moist longer, so you will need to be careful not to overwater. It is recommended that you wait until the top inch of the medium is dry before watering the plant again. To test this you can use the lead pencil trick (the point of a sharpened lead pencil, when inserted into the medium, will darken with moisture if the plant has enough water).
Also, be mindful of the type of orchid that you are planting in the peat mixture; some types such as the Phalaenopsis make take watering less frequently in a peat mixture as opposed to being planted in bark. The dry mixture is also very lightweight and may pose a concern for top-heavy plants when paired with lightweight pots; to keep plants firmly rooted consider planting in clay pots.
Dear Orchid Doc:
Recently, I’ve noticed that my Phalaenopsis is very limp and the blossoms are falling off. Is there anything that can be done to revive it?
Sharon W
Dear Sharon W:
The leaves and stem of your Phalaenopsis should be firm. Limpness is a sign that the leaves do not contain enough water to maintain its normal turgid state. However, the problem could have also been caused by overwatering. Phalaenopsis roots like a lot of air. If the plants are overwatered the roots will stay soggy in the wet medium. Over time, soggy roots will rot. Once they’ve rotted it is hard for them to absorb moisture and then the leaves take on a limp appearance. To confirm the source of the problem, you may wish to take the plant out of the pot and examine the roots. Do so carefully.
Dear Orchid Doc:
I have recently moved into a new apartment and there are no windows which allow for direct sunlight. I was told that I could substitute this for artificial UV lights. Are there any drawbacks to growing my Cattleya using only artificial UV lights?
Jordan E
Dear Jordan E:
Where there’s a will, there’s a way. In cases where natural sunlight is insufficient or unavailable orchids can still be grown under artificial plant lights. Orchids grown indoors under good artificial light can be just as healthy as the ones grown in natural light. This technique, however, will require more than simply placing your orchids close to a light bulb. Having a basic understanding of plant lights and your orchids’ light sensitivity and requirements is paramount.
Cattleya orchids require sufficient light for healthy growth and flower production. For your specific conditions, you will need four 40 watt fluorescent tubes and two 40 watt incandescent bulbs directly over the plants. Your plants should be naturally erect, without need of much staking, and of a medium olive-green colour. Dark green, limp foliage indicates too little light. Best of luck.