ANATOMY 05 — RHIZOMES & NEW GROWTH

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 A rhizome is a horizontal stem that connects one growth of a sympodial orchid to the next. Instead of continuously growing upward from one central point, these orchids gradually travel sideways as new growth develops.

You’ll commonly see this growth pattern in orchids such as Cattleyas, Oncidiums, Cymbidiums, and Zygopetalums.

The rhizome may not look particularly important. It can resemble a short stem running between pseudobulbs, sometimes sitting right at the surface of the potting mix. But it connects older growths with newer ones and plays an important role in how the orchid expands.

New shoots often emerge from growing points near the base of existing growths. When they first appear, they can be surprisingly small and easy to mistake for a root or something that should be removed.

Be careful around new growth. Young shoots are tender and can be damaged while repotting, staking, or moving your orchid.

As the plant grows, the rhizome also tells you which direction the orchid is traveling. This becomes especially important when choosing a pot and deciding where to position the orchid when repotting.

Once you learn to recognize the rhizome and new growth, you can actually see where your orchid is headed next.

 A flower spike is one of the most exciting things to discover on an orchid. It’s the structure that will eventually carry the buds and flowers you’ve been waiting for.

You may also hear the word inflorescence. An inflorescence is the complete flowering structure of the plant — the flowering stem and the flowers or flower clusters it supports.

Flowering structures can look very different depending on the orchid. Phalaenopsis commonly produce flower spikes from between the leaves, while many sympodial orchids such as Cattleyas, Oncidiums, and Cymbidiums flower from new or recently matured growths.

When something new first appears, resist the temptation to immediately stake, bend, or cut it. Young flower spikes can sometimes be confused with roots or new vegetative growth.

As the spike develops, you may begin to notice nodes, branches, buds, or other signs that flowers are on the way.

And remember: a flower spike is the result of everything that happened before you ever saw it. Healthy roots, adequate light, proper watering, and mature growth all help your orchid build the energy it needs to bloom.

Learning to recognize a flower spike lets you protect it from the moment your orchid begins preparing its next show.

 Once buds begin forming, your orchid is entering one of the most exciting and sometimes most sensitive stages of its growth cycle.

Buds develop along the flower spike or inflorescence and gradually swell as the orchid prepares to bloom. Inside each developing bud, the flower is already taking shape long before the petals finally open.

During this stage, consistency becomes especially important. Sudden changes in temperature, watering, light, humidity, or the orchid’s environment can sometimes cause developing buds to stop growing and fall before opening. This is commonly called bud blast.

You may notice buds beginning very small and tightly closed. As they mature, they usually become larger and fuller, and you may begin to see the flower’s color through the outer surface shortly before it opens.

Try not to rush the process. Depending on the orchid and growing conditions, buds may take days or weeks to develop and open.

Once the first flower opens, others along the inflorescence may follow gradually, giving you the chance to watch the display unfold one bloom at a time.

A developing bud is the final stretch of a journey that began with healthy roots, leaves, and new growth.

 Bud blast is the term growers use when an orchid's developing buds stop growing, shrivel, yellow, or fall from the plant before they open.

It can be disappointing—especially after waiting weeks for a flower spike—but bud blast is usually the orchid responding to a change or stress in its environment.

Sudden temperature changes are a common trigger. Cold drafts, blasts of hot air, heating or air-conditioning vents, and moving an orchid between very different environments can all affect developing buds.

Changes in watering can also play a role. Allowing an orchid to become unusually dry while it is developing buds—or suddenly keeping the roots much wetter than usual—can stress the plant.

Low humidity, insufficient light, root problems, and exposure to ripening fruit can contribute as well. Ripening fruit releases ethylene gas, which can cause orchid buds and flowers to age or drop prematurely.

If one bud blasts, don't assume the entire flower spike is lost. Other healthy buds may continue developing normally.

Most importantly, don't respond by dramatically changing everything at once. Check the roots and growing conditions, correct any obvious problem, and then give the orchid a stable environment.

Once buds appear, consistency is often more valuable than trying to make conditions perfect.

For the final photograph, I would not use a beautiful blooming orchid here. We want this image to teach diagnosis. Eventually replace it with a close-up showing yellowing, shriveling, or aborted orchid buds still attached to a flower spike.

Once a bud has begun to yellow, shrivel, or dry out, it usually will not recover and open normally. But that doesn't mean the rest of the flower spike is lost.

If the remaining buds are still green, firm, and developing normally, leave them alone. They may continue growing and bloom without a problem.

Take a look at what may have changed recently. Was the orchid exposed to a cold draft? Did the potting mix become unusually dry? Was the plant moved, exposed to excessive heat, or placed near an air-conditioning vent?

Correct any obvious problem, but don't dramatically change everything at once. Developing buds generally respond better to a stable environment than constant adjustments.

If the damaged bud eventually dries and falls away, that's okay. Allow it to drop naturally. Your orchid can redirect its energy toward the healthy buds and flowers that remain.

You may not be able to save a bud that has already blasted, but you can often protect the buds that are still developing.