Most normal orchid roots are a silver-gray color that turn green when watered. They occasionally can be yellow due to lack of sunlight, which in this case are still healthy roots. When they aren’t healthy, orchid roots turn brown or black, lose their format and become mushy.
Yet sometimes, orchid roots display other colors that we aren’t expecting, such as dark purple, magenta red, or light pink roots. This article will focus on what the dark pink or purple roots mean and provide 7 reasons for why orchid roots change to this color.
What do pink or purple roots on my orchid mean? There are seven reasons that orchid roots change colors to a pink or purple: genetic predisposition, prolonged use of tap water, nutrient deficiency, discoloration from spikes, pigmentation in the fertilizer, reaction to over watering, and a natural UV protection from sunlight.
Purple Root Tips on a Neofinetia falcata Orchid Let’s look at these one by one but before I dive into the details, know that the odds for your orchid being infected are extremely low. The higher probability is that your orchid is doing fine and will continue to do fine, so you can let out the air you’ve anxiously been holding in since you repotted.
1) Genetic Predisposition Turns Orchid Roots Light Pink
In some cases, the orchid will naturally have light pink roots. This is very common for Phalaenopsis with pink or purple flowers. It’s also common with Pulcherrima, Cymbidium, Isochilus Linearis and Neofinetia Falcata.
The list is probably immensely larger than what I just typed, but this is what I can prove and back up with research. Truth is, probably any orchid that has a pinkish-purple flower might have this predisposition in its genetic code that will turn the roots pink. You can also hint at having pink or purple roots if the flower spike has purple undertones to it or the leaves have a purplish glare under them.
This condition is not uncommon. In fact, in Japan the Neofinetia Orchids which had pink roots were considered to be a sign of wealth and rank. Shoguns and Samaurai had their share of pink-rooted orchids, while others just dreamed about having one.
These “special roots” were so delicately prized that new ways to display them were created, including the kokedama. If you want to read more about how to make a kokedama, this article is a good place to start.
Succulents, which are somewhat related to orchids in the way of care grow aerial roots which start out pink. As they mature, they turn white. Red roots are seen as a sign of rapid root growth. The new roots are still in development but growing faster than they can provide the right pigment.
Anyway, pink and purple orchid roots are perfectly normal in some varieties of orchids. It is their genetic predisposition, and you have nothing to worry about. If your orchid is healthy, blossoming, and growing, then you’ve been blessed.
2) Prolonged Use of Tap Water
Depending on where you live, the tap water can display a horrific number of chemical elements and compounds that are detrimental to your orchid. In Kansas, I found out the hard way that my tap water was extremely alkaline (8.5 pH) and I’ve killed my share of orchid due to that.
It’s not only the pH of the water that will turn your roots pink. In fact, it’s more due to the other chemicals that interact with the roots tips that lack velamen (the very end of the roots where it’s normally green does not contain velamen).
The various chemicals included in the tap water can change root pigmentation slowly, and over time, the roots will transform into a pinkish-red color.
The last variable in the tap water that contributes to purple root tips is a bundle of microbes. Inevitably, pathogens can get through the filtering system and into our potting medium. These pathogens will interact with the roots and even though they might harm the roots, they will provoke a change in color due to chemical reactions.
I’ll mention 2 of the microbes below, but the chances of this happening are very rare. It’s most likely the other chemicals in your water that are changing your orchid root’s color.
3) Nutrient Deficiency Causes Change in Root Color
If in the example above the chemicals in the water were too high, another possibility lies in the other end: the nutrients are too low. Lacking nitrogen and oxygen will turn the roots a ruby color. If you have a higher sodium count in your fertilizer, this can interfere with how well the other elements are absorbed. High sodium count blocks the plants ability to take in other nutrients, no matter what they are.
You can tell if you have a high sodium count in your water because of the salt build-up on the top of your orchid pot. It will look like sparkly, shiny, glass or diamond specks when the sun hits. In other cases, it looks like sugar crystals that accumulated on the top of the bark or leca pebbles.
In either case, of number 2 or number 3, you can fix this problem by not using tap water anymore to water your orchids. You’ll need to use either distilled water, rain water, or reverse osmosis water. I wrote an article a few months ago about the different types of water and which is best for each orchid, which you can read here.
4) Discoloration of the Support Stakes into the Roots
One thing I never thought about before researching this article is what happening to the colorful spikes we use to stake our orchid with?
Some of the discoloration in the roots can come from tinged or tinted wood used to decorate the stake. After long watering periods and constant interaction with the orchid back, sphagnum moss, and other items in your potting medium, the pigment soaks into the surrounding material, including roots.
If this is the reason, the sphagnum moss will also be tinted. Make sure you are using bamboo skewers or plastic stakes that do not fade into the roots or sphagnum moss.
Just like the blue dye on orchids will not do harm and most companies swear they are pet-friendly, there is nothing that states what chemicals are being used make the dye. (You can read more about blue orchids here.) Much less is said about what pigments are being used to decorate the stakes that support the flower spike.
Always check what you are using in your potting medium.
5) Pink and Blue Fertilizer Can Modify Orchid Root Color
More common than not, your orchid fertilizer is either pink, blue, or green. Most fertilizer will turn disappear when mixed with water, but the blue pigment is slightly present even after mixing. Over time, this overly treated fertilizer can change the root color.
I highly suggest changing fertilizer for the time being and see if this is the underlying cause.
Even though there is nothing to “put my finger on” and say this is the reason why, if the fertilizer is interacting chemically with the roots enough to provoke a change in color, then it’s probably not the best for your orchid.
There are so many other fertilizers out there, and in this article, I explain 5 different methods you can use to fertilize. I strongly suggest the change.
The only positive side to keep your current fertilizer is the health of your orchid. Pink or purple root tips are not a negative sign due to lack of good health, but just a chemical indication that some interaction is happening at the orchid root level. If your orchid seems to be growing and flourishing, then keep the fertilizer. I wouldn’t risk it if it were me.
Fertilizers are not the only cause. Fungicides are also included as culprits. Since fungicides are applied over a series of weeks then the applications halted, your older roots would be tinged/tinted and the newer roots would be green. The color build-up would be the result of a chemical reaction that would appear in the most sensitive part of the orchid—new roots.
6) Purple Roots are a Sign of Over Watering
Remember when I said that the roots could change due to lack of nutrients, specifically oxygen and nitrogen? This lack is not necessarily due to lack of nutrients per se but the lack of air that is circulating inside your pot. When the potting medium is packed so tightly, it’s hard for the roots to perform gas exchange. The air is not being renewed and toxins start to build up in the roots.
One of the signs of this, even though more rare than other signs, is the turning colors in the roots.
You can be assured that the over watering is the culprit if the roots then turn to dark purple then black. They will die off if the underlying cause is not dealt with: over watering.
Remember, over watering an orchid can be 2 things: watering too much or watering too frequently. The amount and the frequency are both involved. You might be watering every 5 to 7 days, but you might be drenching the poor orchid and drowning it.
Another problem that is related to over watering is having a potting medium that doesn’t drain fast enough, and water pools inside the media. Sphagnum moss is the worst for this, and over time it becomes too compacted to allow good air flow. Make sure water is exiting your pot as fast as it enters, and keep the water flowing.
7) Natural UV Protection from Sunlight
Orchid roots have chlorophyll that capture sun’s rays and turn them energy. The chlorophyll turns the orchid roots a vivid green color. When not in contact with humidity, orchid roots are slightly grey. Yet when the roots are buried inside the potting media, they receive no direct sunlight.
In this case, there is not reason to have chlorophyll, so they turn pale yellow. If you want to know more about yellow roots, if to cut them, how to clean them, and if they are healthy, check out this article I wrote as a guide.
Imagine these pale-yellow roots inside the pot and you change suddenly to full water culture and now they get light 12 to 14 hours a day. This is like me going to the beach in Rio de Janeiro in Brazil without sunscreen. The roots burn. I burn.
Unlike me, orchid roots have a natural sunscreen called anthocyanin pigments that turn the leaf freckled with purple spots.
These purple spots are a great indicator to know what light level you are providing to your orchid. It’s in the brightest possible light and still thriving, but it had to protect itself, so the orchid produces sunscreen.
The roots can do this too, but it is a very rare phenomenon. Either that, or it’s just not documented very well.
The purple pigment in the roots is the orchid’s way of protecting the fast-growing roots to over exposure of light. Even though the roots are not sun damaged, the orchid is making sure they stay healthy. If you notice, only the newer roots will be purple. In time, if the cause is truly sun exposure, this purple color will go away because the roots will adapt to their new conditions.
What if My Orchid Is None of the Above? Is it Infected?
If you feel that none of the 7 reasons above apply, there are two more that can cause a turning of root color: Fusarium Wilt and Rink Root.
The first one is called fusarium wilt. Fusarium wilt is a fungal pathogen that will discolor the roots, but it also will not stop at pink and purple roots. This is just the beginning color for this fungus infestation. The roots will continue to turn red and then to brown before they die. (Source)
It is more likely that the overwatering is turning your orchid roots pink that the fusarium wilt is, yet fusarium does like soggy moist environments. Where one is present, the other tags along. To verify that this is in fact the culprit, the leaves and flowers of your orchid will wilt (thus the name).
The second unlikely probability is an infestation called Pink Root. I say unlikely because pink root likes to infect alliums, which are plants that include onions, garlic, scallions, shallots, leek, and chives.
It’s not something you’d get a at a hair salon, so beware of what you type into google.
The pathogen called Phoma Terrestris lives in the soil, and whatever is planted there will slowly wilt and the produce is turned to junk. There is not one little onion that makes it to market.
I say this cause is unlikely because it is rare that this pathogen will infect orchid bark. It can happen but not probable. On top of that, they don’t even like orchids. They like onions. So, combine those two, and there’s a not a decent chance that this is killing your orchid.
The roots on both of these will be bright pink, dark pink, or a light lavender color. Go through the other 7 reasons first, and if it’s not those, then it’s probably fusarium wilt.
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I hope this article was helpful in finding out what is causing the purple or pink roots on your orchid. If it was, please leave a comment below. 🙂 I’d appreciate it.