Orchid Stem Turning Red, Yellow or Brown: What Does it Mean?

Orchid Stem Turning Red, Yellow or Brown

What do Venezuela, Singapore, Seychelles, Indonesia, Honduras, Guatemala, Costa Rica, Colombia, Cayman Islands, Brazil and Belize have in common?

Go ahead and think about it for a minute. You can’t think up the answer?

Let me help you out. These countries all have various species of orchids as their national flowers.

This is not unsurprising as orchids are deserving of any and every recognition they get as they are one of the best plants the world over.

You’re reading this article because you want to know why your orchid’s stem has turned yellow, red or brown so it’s very likely you share this same sentiment.

Orchid’s Stem Turning Red, Yellow, or Brown

In determining why your orchid stems are turning red, yellow, or brown, it must be first understood that most persons with this problem tend to use the word “stem” to collectively or interchangeably refer to the flower spike of the orchid and the actual stem of the orchid.

The distinction between both is that the flower spike is the site at which orchid blooms emerge. The stem, on the other hand, is where both leaves and the flower spike emerge from.

As described earlier, the stem could be lengthy growing variety in monopodial orchids or the engorged pseudobulbs in sympodial orchids. Still, for the sake of clarity and ease of understanding, the “stem” word will be used interchangeably. 

Orchid stems are normally green in color and this color is a signal of the good health status of the orchid plant. Under certain circumstances, the stems may change color to red, yellow or brown. These circumstances are described below.

First, an orchid’s stem-changing color and becoming brighter color can be an indicator of the amount of light the plant is receiving. Cattleya orchid species have been known to turn a shade of red when they receive adequate light.

In some other orchids like the phalaenopsis, the change of color to red or yellow is an indicator that the plant is getting too much light and is being scorched. In essence, orchids may change color in reaction to adequate sunlight or too much sunlight in the same way humans become tanned from being exposed to the sun.

Striking the balance between whether the light is adequate or too much might be difficult but it would be better to err on the side of caution and assume the light is too much.

To remedy the situation, the orchid plant should be relocated to a position where it receives direct sunlight instead of full direct sunlight or properly timed artificial lights could be employed in place of sunlight.

Ultimately, knowledge of the particular orchid species and its lighting requirements will provide the best guide.

Secondly, orchid stems may change color to yellow or brown as a kind of signal or proof that the stem is done with supporting life. This is especially the case when the color change occurs after the plant has finished blooming and dropped all its flowers.

It may also occur at the stage where blooms have almost completely fallen off the flower stalk. In blooming, orchids expend a great deal of energy and resources and usually enter a period of dormancy where its energies are refocused on extending its roots, growing new leaves and possibly new flower spikes.

As such, the old flower spikes die out and in dying out become discolored. In a bid to encourage the orchid plant to rebloom, the worn out stem will need to be cut off. This is because most orchid species rarely produce blooms more than once from the same flower spike.

In the scarce instances where they do, the blooms produced will feature smaller and fewer flowers. How then should the worn out stem be cut? First, to cut off the worn out stem, shears, scalpels or blades sterilized properly with 70 percent rubbing alcohol are the cutting tools to be used.

The sterilization is meant to ensure that no harmful bacteria is introduced to the plant. The cutting is best done when the orchid plant is not in bloom (or has dropped all its flowers). In the case of dead stems or roots that have become brown and shriveled, they are to be cut off completely from the base.

In the case of promoting reflowering, pruning of a flower spike that is just beginning to brown at the top should be done at least an inch above the node closest to the lowest flower bloom of the flower spike (in its still green base).

This will spur the plant to produce a new flower spike out of the cut one.  If the flower spike is completely brown and therefore unhealthy, it should be trimmed from the base of the plant.

This will encourage the plant to produce an entirely new flower spike. If the orchid is double spiked, the spike should be cut ideally, from the base on one spike and an inch above the node closest to the lowest bloom on the other.

This will cause the spike to devote all of its energy on the one spike that is cut partially. In the case that both spikes are completely brown, they should both be cut off completely. In the case of partial browning, the guide for single spikes above can be applied.

In all of these instances, the cut to the plant should be a single clean cut and fungicide should be applied directly to the exposed cut surface to prevent fungal attacks. Cinnamon can be used as a homemade fungicide.

Finally, an orchid’s stem may change color to yellow, red or brown as a result of the orchid becoming diseased. Black rot or bulb rot are the likely disease culprits causing the change in color of the orchid’s stem.

With bulb rot, evidence of this disease in sympodial orchids is that an old back bulb changes color to brown and becomes mushy and decayed. Black rot, on the other hand, presents the same symptoms but on one or many newly produced pseudobulbs.

The rot typically starts at the base of the bulb and spreads outward. These diseases are most likely caused by overwatering. Other than disease, older pseudobulbs naturally become brown and shriveled once the plant has exhausted all of their energy reserves. 

For the plant’s health, such browned diseases or old pseudobulbs should be cut off completely. The cut should extend to the rhizome especially where the affected bulbs are at the end of the rhizomatous base.

After such cut, the exposed cut parts should be covered with fungicide.  In the instance where the affected bulbs are in the center of the plant and (or) can’t be cut out easily, repotting of the plant might be the only solution to ensure the continuity of the plant’s life.

The foregoing are the reasons your orchid plant’s stem might change color to yellow, red or brown and the possible ways to care for the plant in such instances.

What Else Must You Know About Orchids

Orchids are among the most diverse of flowering plants. There are about 30 thousand species of orchids known to man currently and approximately 200000 hybrids already developed and many more still being developed.

This large numbers ensure that orchids claim about 6 to 11 percent of the total number of the planet’s seed plants. They are also the world’s largest group of flowering plants.

By virtue of this large population, orchids are also quite widespread with orchids having been found growing naturally in every habitat on the planet with the Polar Regions and extremely arid desert areas being the exceptions.

This being the case, orchids can be cultivated by almost anybody in any part of the world and quite easily too. It will therefore not be out of place to assert there’s an orchid well suited for every flower loving person on the planet.

Orchids are quite popular and can be easily identified by most people. Identifying orchids in this sense doesn’t necessarily mean being able to tell the exact orchid specie but rather being able to distinguish an orchid from other flowering plants.

This popularity is certainly not unconnected to the colorful appearance of orchids which appeals greatly to the eyes. Their beauty, which is evident in their sometimes ornamental leaves and exotic flower blooms adds a definite ambience to any setting in which they are found. Orchids are also popular for the wide array of fragrance which they give off.

Morphological Similarities in Orchids

The many species, hybrids and clones of orchids share certain features which identify them as being members of the same family. These features are chiefly structural or morphological and relate solely to their flowers.

Particularly, its flowers possess fused stamens and carpels (which are the male and female reproductive parts of the flower) and display zygomorphism. This means that the orchid plant’s flowers can be bilaterally divided into two mirror halves.

In addition it’s flowers resupinate, that is they grow in a twisted fashion and can twist as much as 180 degrees. Again, they possess highly modified petals and produce millions of microscopic seeds that lack an endosperm and require the action of a special fungi to germinate.

Classification of Orchids

Orchids are perennial herbaceous plants. This means that they have the ability to live for more than two years. This is in distinction to annuals and biennials which cannot live for more than a year and two years respectively.

Other than the index of lifespan, orchids can be classified using a number of indices to aid in understanding them better. These indices include preferred climatic conditions, growth pattern and natural habitats.

In classifying orchids according to their preferred climatic conditions, orchids could be cool, intermediate or warm climate orchids. These descriptors are self explanatory indicators of the temperature ranges within which orchids are at their optimum.

Cool climate orchids prefer environments with lower temperature registers and access to cooling agents such as shade, cold rain or the occasional snow fall. Intermediate climate orchids are better suited to neither too hot or too cold environments.

Warm climate orchids prefer warm humid conditions. Zygopetalums, Miltoniopsis, and Calanthe are each examples of cool, intermediate and warm climate orchids respectively.

On the basis of growth patterns, orchids can be classified as either having sympodial growth habit or monopodial growth habit. 

Sympodial growth habit in orchids is reflected when an orchid plant grows laterally or horizontally. In this case, the orchid has a rhizomatous base or shoot from which engorged stems known as pseudobulbs emerge.

The rhizomatous base acts like a kind of thread holding the pseudobulbs together. These pseudobulbs are engorged because they function as storage organs. Nutrients as well as moisture are stored in the pseudobulb for use by the plant during harsh or other unsuitable periods, for instance drought.

The pseudobulb serves as the base from which leaves, flower spikes, and flowers emerge. Once a pseudobulb is spent, a new pseudobulb emerges at its base while the spent pseudobulb becomes a back bulb.

The back bulb continues to support the growth of the new pseudobulb with its last energy reserve until it becomes shrivelled and dies off. This process continues in perpetuity and thus guarantees the indefinite lifespan of the orchid.

It is a fact that the greater majority of orchid species display sympodial growth habits. Examples of sympodial orchids are Cymbidium, Bulphophylum, Cattleya, Oncidium and Dendrobium.

In an orchid plant displaying monopodial growth habit, a single stem growing vertically upward is produced. Out of this stem, new leaves emerge on alternate parts of the stem. These new leaves emerge at the stem’s apex and will continue to emerge for as long as the plant remains alive.

As such, monopodial orchid plants can grow quite tall extending many meters above the ground. In monopial orchids, older leaves at the base of the plant may drop off or be cut off when they are completely spent and dead.

On the basis that orchids live indefinitely, this process will, theoretically, continue without end. An exception to this is the production of terminal spikes by certain monopodial orchids. A terminal spike grows from the center of or in-between the leaves of a monopodial orchid.

By its growth, the orchid is prevented from producing any new leaves thus guaranteeing that the plant will die out. This is because the leaves of monopodial orchids tend to be succulent, storing moisture and nutrients for the plant’s use.

The production of terminal spikes by monopodial orchid plants is random and is therefore not the norm. Monopodial orchid plants which produce terminal spikes may produce keikis, which are baby plants that are exact clones of the mother plant, and can be used to “continue” the life of the original orchid after it dies. Examples of monopodial orchids include Vanda, Vanilla and Phalaenopsis.

With respect to the classification of orchids by their natural habitats, orchids could either be terrestrial, epiphytes or lithophytes.

Terrestrial orchids are those which grow on or from the ground. This set of orchids have an actual connection to the ground and derive their nutrients from the soil from which they grow.

Terrestrial orchids typically possess root tubers which stores nutrients and moisture for the plant’s use during periods of unsuitable environmental conditions. These tubers used to be consumed by early Aborigines as a tuber crop.

On a number scale, there are more epiphytic orchids than there are terrestrial orchids. In fact, terrestrial orchids make up less than one percent of the total global orchid population. Examples include Stenoglottis, Disa uniflora, Bartholina and Satyrium.

Epiphytic orchids are somewhat like parasites on the basis that they grow on a host. They are more likely to be found growing naturally in the tropical and subtropical parts of the world. An epiphytic orchid has as its preferred habitat, the various parts of other plants.

An epiphytic orchid will most likely be found growing on the bark of tree trunks or clinging to strong lower branches of trees or even attached to twigs on the tree canopies. Epiphytes are able to attach themselves to other plants by virtue of the highly modified root networks they possess.

In the case of epiphytic orchids, their aerial roots are strong and used in attaching to the host to help provide the plant with structure. The comparison of epiphytes to parasites is restricted solely to the point that they grow on hosts.

Unlike parasites, epiphytes do not harm their hosts nor deprive them of the nutrients they are entitled to. Epiphytes absorb needed nutrients and moisture from.the environment as well as from organic materials that might collect on the surface of their hosts.

In the case of Orchids, their older roots are covered with a tissue of dead cells known as the velamen which aid it in the absorption of needed nutrients. The points at which epiphytic orchids attach to their hosts is a clear indicator of the amount of light the orchid requires.

Specifically, those attaching to twigs on tree canopies would receive more light than those which prefer to attach at shaded lower points. Popular orchids that are epiphytic are Oncidium orchids, Miltonia orchids and Cattleya orchids. 

Lithophytes are pretty much similar to epiphytes with the sole distinction being that the host of lithophytes are rocks and other rock crevices. This breed of orchids are not afraid of height and grow well at high elevations. They will most likely be found growing naturally in the tropical parts of the world.