It’s hot in July!

By July, most spring blooming orchids have completed their flowering cycles and most orchid plants are in a growth cycle, producing new leaves and roots needed to generate the energy they need for next spring’s bloom cycle. This is one reason I advocate cutting those Phalaenopsis bloom spikes all of the way back so as not to induce secondary spikes that are not all that pleasing anyway, and that keep the plant totally drained of energy, leaving nothing for next year.

This is also the most important time of year for a comprehensive feeding and watering schedule. Orchid plants need food and water year round and more so now than ever while they are in active growth. Additionally, it is imperative that the growing media that those new roots are weaving their way through is fresh and promotes root growth and not root rot. I continually have people asking me what to do with their orchid plants while they are dormant and I have to explain that most orchid do not have a dormant season, especially not Phalaenopsis orchids; they are performing many important tasks while they are not burdened with maintaining flowers.

Feed in spring and summer with a fertilizer that has plenty of available (non-urea based) nitrogen. I feed all of my orchids weekly when they are in active growth alternating high nitrogen and high phosphorus formulations. But remember that overfeeding (mixing the fertilizer stronger than the label recommendation) can burn the leaves and roots.

Protection from the hot sun is also essential to keeping your orchid leaves healthy. Moving them outside is often tempting and given the right sun filtering and protection from those things that would love to eat them, it can even sometimes be a good idea. But direct midday sun is far too hot for almost all orchids. Our greenhouse has a layer of 50% shade-cloth over the entire roof and even that is not enough for Phalaenopsis and slipper orchids, for which I have installed a secondary shade-cloth layer.

Anytime you move orchids into a sunnier and hotter location, use caution and monitor leaf temperatures, for it is the buildup of heat in the leaves that causes the most damage. If you visit us at the Carrboro farmer’s market, notice that in the early morning the plant tables are near the east edge of the tent so that the plants get full sun, but by mid-morning we move that back into full shade once I notice that heat is beginning to build up in the leaves.

In my greenhouse I have large exhaust fans that move air over the plants and help to avoid that heat buildup, and even in a sunroom it would usually be a good idea to use a fan to increase air movement.

So ensure that your plants are well-potted, well-fed, and get the amount of sunlight they need. Enjoy watching the new roots and leaves grow, which will enable the plants to maximize their strength and ability to produce a better flowering in their next flowering season. And remember, we are always available for specific questions or for orchid supplies.

Author: Bob

Bob has been growing orchids since 1985 and commercially since 1989. He has had several orchid articles published in the AOS Bulletin, AOS Culture Guide, and in Orchids Magazine. He currently resides in Chapel Hill, NC and runs Carrboro Tropicals, Chapel Hill's only provider of locally-grown orchid plants.

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