Plant Encyclopedia

Lady slipper orchids, genus Cypripedium – what to look for when buying them


Perhaps no other group of terrestrial orchid is as popular as the lady slipper orchids, genus Cypripedium. As I said in my articles about Cypripedium cultivation, relatively few species are in mass production, so many on the market today are wild sourced plants. While some condemn this practice, I am not here to do so, I only want to address the issue of how to recognize a healthy plant to insure success for the buyer. Necessarily, many wild collected Cyps are not in good health due to rough treatment during collection, poor storage before going to market, and the process and time involved in transporting them to their new homes.

 

Cypripedium tibeticum healthy

We all want to have healthy Cyps in our gardens such as this lovely Cypripedium tibeticum in Darcy Gunnlaugson's garden in Canada. To have such a plant though it needs to have healthy rootstock.

 

Moreover, it should be noted that while the mortality rate of wild collected material is often high, plants can be stabilized over time in culture and in time look like nursery propagated stock. Since the purpose of this article is to recognize the indications of health of a Cypripedium, that will be my main focus.

The characteristics of an unhealthy plant indeed are often due to the collecting process, so it is important to know what those characteristics are, and if at all possible, avoid purchasing such stock. Of course not all collected material is in poor health, however the lion’s share is in my experience.

Furthermore, this article is about mature plants, not seedlings. Usually seedlings are sold soon after being removed from their propagating jars (commonly called deflasked seedlings) and are very small. Once you have seen deflasked Cypripedium seedlings it is impossible to mistake wild collected material with them. Still, some vendors market very small collected plants as “seedlings” – a questionable practice since such plants have an even higher mortality rate than adults.

 

 

 

 

Without further ado, here are things to look for when assessing a Cyp’s health:

 

Healthy Cypripedium roots

The roots of a healthy Cypripedium are light in color, not broken or cut, and the root tips are intact. These roots exemplify all those attributes.

1. The roots should be clean looking, white to cream colored, with little or no black on them, particularly the root tips. Some species can have brown roots due to heavy organics in the compost staining them, but most will not have this. Recently collected plants will rarely have light colored roots, even if they are undamaged, but rather moderately dark to dark brown roots. Unhealthy plants will have black roots and many will be dead or dying, the result of invading organisms – fungi and bacteria. Another problem are clean looking roots that break off easily from the rhizome during handling. While it is normal for a few roots to come off during transit and planting, most should be firmly in place.

 

2. The roots should be whole and end in nice healthy tips, not cut off. Length can vary but should not be much less than 12-15 cm on average. Healthy root tips have a rounded shape and if fully grown will end in a blunt tip, but unbroken. Growing root tips will be more conical and the color of the tip will often be a slightly different color – yellowish, greenish, or even tan or white.

Sick Cypripedium roots

These roots are typical of an unhealthy plant. They are cut off at the ends (you can see the wiry stele protruding) and dark in color. Such roots invite infection into the plant and will themselves die within a short time.

Roots that are broken off, cut off, black in color, or very short (less than 8 cm or so) are not healthy. This usually is the result of poor collection, but can sometimes be due to poor cultural conditions as well. A tell-tale sign of really sick roots are broken off tips where the outer root (velamen and cortex) has detached and only the wiry inner root remains (the stele). Roots with these tips are inevitably doomed, however the plant can survive as long as infection is controlled and doesn’t spread to healthy tissues.

3. The rhizome can be dark in coloration, even black, but not decaying. You can try smelling it – if you smell any rotten odor, there may be a problem. The rhizome as well should be very firm to the touch and unbroken. Softness indicates unhealthy tissue and should be cut away fully. The cut end probably should be treated with an antifungal to prevent invasion of organisms. Powdered sulfur can be used or the whole plant can be soaked for a short time in fungicide before planting.

If you are concerned about buying collected plants, the rhizome should be fairly short, not more than a few centimeters. A long section of rhizome with many growing points and branches often means the plant was wild collected because these plants are slow growers. Most species have not been artificially propagated long enough to produce long rhizomes. Cultivated, large, well clumped plants take 10 or more years to develop even in the most vigorous species like C. reginae. In the wild a clump of similar size might be many decades old.

Healthy Cypripedium eyes

These growth buds (sometimes called "eyes") of Cypripedium x ventricosum are in good health. They are light colored, pump, and firm to the touch.

New roots on a Cypripedium

These newly growing roots on a collected Cypripedium macranthos are a good sign, but the plant has a ways to go before it is fully recovered.

 

4. The plant should of course have nice plump, healthy growth buds for next year. Bud size and shape can vary widely from species to species as can root size. In some species like C. japonicum the buds can be quite formidable, but the roots rather short, while in other species, such as C. reginae, the buds as well as the roots are large and the latter can extend for two or more feet. On the other hand, dwarf plants such as C. debile will have buds and roots comparable to a seedling of most other species.

The coloration of the buds should be as with the roots, white to creamy colored. Some seedlings may show green color in the buds now and then. Some flecking of dark spots is not uncommon, and usually not a sign of any problem. Darkened buds are suffering, but may grow depending if the inner tissues are damaged or not. Again, in most cases, darkened buds, broken buds, and rotting buds are the result of the collecting process, and should be avoided.

Healthy Cypripedium plant

This Cypripedium x ventricosum is a good example of a healthy dormant plant. Despite its excellent health, this plant was likely wild collected some years earlier.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In the course of building a collection of lady slippers you no doubt will end up buying plants that have some of the above mentioned problems. Depending on how bad a condition they are in, you have to decide if you want to try to stabilize them, or look to get a refund. I know of many wild collected plants that were in trouble and within a few years were brought back into a healthy state, however this was done by very knowledgeable growers. Even they don’t always succeed. Indeed the mortality rates of some species such as the spotted leaved Cyps (section Trigonopedia), can be nearly 100% within a few years. Members of section Cypripedium are more capable of withstanding poor treatment, and if handled well can stabilize within a few growing seasons.

If you do try to save an unhealthy plant be sure to remove all suspect tissue – rotting, soft, and black parts should be carefully cut off with a sharp, clean knife or scissors. I recommend starting at the end of a bad root or section of rhizome and cutting a bit off at a time until you hit healthier tissue – usually a lighter color or in the case of rhizome, stiffer and resistant to being cut. Growth buds that are soft should be wholly removed since they will not grow and only spread infection. Then soak the whole plant in funicide for 10 more more minutes, but don’t overdo it.

The plant can then be potted into any completely inorganic mix – small grain pumice, sermis, soil perfector, gravel, sand, perlite – any of these will do, or a mix of them. Using organic material at this point is a bad idea since fungi and bacteria will be introduced as well. Keep the plant in a more sheltered spot for the first season (a cold frame in bright shade with good air circulation would be ideal). Be careful to keep the compost evenly moist, and use fungicide on a regular schedule during growth to stop any spread of disease to the new growing tissues. Wet down the whole pot with funicide, not just the leaves, since it is the roots and rhizome that are most in jeopardy. Monitor the plant carefully to see how it responds. If it stays green and healthy, you can use a very mild fertilzer solution from time to time, but far below the concentration you would for a healthy plant.

Unhealthy Cypripedium

This Cypripedium macranthos may look like a lost cause, but with careful treatment it could be restored to health. In fact it was within a couple growing cycles. Such plants have to be babied for a couple years and should never be planted directly into a garden setting.

If you can pull the plant through the first season, there is a chance it will survive. After dormancy in the fall, remove it and inspect it for new growth. As before cut away any dead tissue, and repot in the same manner. If it responded well, it will have new growing roots and eyes. These are the hope for the future! In the following growth cycle, treat the plant in a similar fashion. If it remains healthy looking you can back off on the fungicide and increase the fertilizer. Go through the repottting process again in the fall. In this way you may be able to stablize the plant in a few growing seasons.

One last comment about the issue of wild collection. Not all wild collected plants are “bad”. In the trade there are plants on the market that have been collected from construction sites or private land, often sold under the “salvaged” label. If correctly collected these can be grown on with no problems. Additionally, the idea that wild collected orchids are always illegal is in itself untrue. Plants existing on private lands or ones that were removed with permission are not illegally collected, and can even be sold. Be careful though, laws should be well understood before you try transporting or selling plants across political boundaries, especially international ones.

Check out this companion video of Cypripedium rootstock:

 

 

Cypripedium macranthos healthy

To show that you can rescue an unhappy plant, here is the same Cypripedium macranthos two years later. There are many more healthy roots, but only one growing point remains. In time this plant will increase in size.

 

Growing lady slipper orchids can be a challenging experience even with healthy plants, so is best to buy from reputable sources. Though the number of nurseries that offer healthy Cyps remains relatively low and prices high, today you can access healthy nursery propagated plants. That was not possible 10 or 15 years ago, so rejoice and join in the fun!

Here are some North American nurseries that grow and sell healthy stock. For a review of these in more detail, plus a few others, check out this review – Where to buy lady slipper orchids online – North American sources.

USA

Gardens at Post Hill, Morris Connecticut
Great Lakes Orchids, Belleville, Michigan (also has Platantheras!)
Hillside Nursery, Shelburne Fall, Massachusetts
Itasca Ladyslipper Farm, Bovey, Minnesota
Raising Rarities, Toledo, Ohio
Spangle Creek Labs, Bovey, Minnesota (seedlings only)
Vermont Ladyslipper Company, New Haven, Vermont
Wild Orchid Company, Carversville, Pennsylvania

Canada

Fraser’s Thimble Farms, Salt Spring Island, British Columbia
Planteck, L’Assomption, Quebec

 

8 Responses to “Lady slipper orchids, genus Cypripedium – what to look for when buying them”

  1. tommy says:

    I am reposting this comment from Ray Price at Great Lakes Orchids:

    “You may want to add Platanthera ciliaris to your data base…Please see my web page and the article on re-introduction of species at the Kitty Todd Preserve on this plant…for “The Nature Conservancy”.

    Ray Price”

  2. tommy says:

    Thanks Ray, I am trying to expand this site bit by bit. As you can imagine, it is a huge endeavor, however a labor of love. I hope one day to find some Platanthera for sale here in Japan, so far I have never seen even one.

  3. I have a question. Last fall I shipped in several different types of cypripediums from Germany as well as some from wholesalers in the US. This spring everything came up beautifully, except that the buds were brown and aborted. We had terrible weather with it getting very warm in early spring, then freezing again. I tried to keep my ladyslippers covered with loose leaf debris through this acquard period of weather shifting. Hopefully my plants will be okay, even though I have very few flowers. Can a cold snap ruin the buds like this, or do I have something else going on? Susie

    • tommy says:

      Hey Susan,

      I think what you are experiencing is indeed due to abnormal weather patterns mostly. In the northeastern US many Cyps were heavily damaged this year due to too much warmth in March and then late freezes in April. That happens sometimes. Since your plants are newly arrived, they likely are not suffering from disease (unless they looked bad to begin with). At this point all you can do is grow them on this season and wait until next spring to see how they establish. Don’t fret too much – as long as the rootstock is in good order they will throw new grow next year, but it may be a year or two more before you see any flowers on the worst hit plants.

      Tom

  4. alice retz says:

    I purchased a lady slipper orchid in the mail, which had been torn from the ground. One leaf was detached and flower stalk was cut 6 inches. Now the other leaf has fallen off. I am trying to maintain the roots in hydroton near a sunny window in house. Is there any possibilities that this plant will survive? thanks alice

    • tommy says:

      Hey Alice,

      Doesn’t sound too good. If the roots are broken/cut short they will get infected and eventually die. Larger divisions can sometimes handle this kind of treatment, but will be reduced in size in coming years until they can rebuild strength.

      One thing’s certain – don’t buy from that source again! Take a look at my suggested sources in North America article to find good places to buy these plants. Yes, people who “rip them out of the ground” often have cheaper prices, but poor quality plants. What species was it BTW?

  5. Jim Bestman says:

    Question deals with treatment for rust spots that appear and if not treated, will
    destroy the stalk of the plant. Plant is otherwise healthy, and sometimes problem continues
    and destroys plant. Cyp Pubescans is plant under discussion, and in past sometimes has
    been a problem, most times not.

    • tommy says:

      Jim,

      Whenever I have problems with a Cyp, my reaction is to dig the plant up to find out what”s going on. Many times it is a root problem. If your plants seem to be in imminent peril, I wouldn’t wait. Of course spring is perhaps the worst time to disturb a Cyp, so there are other factors to think about, for example, are the plants recent transplants or well established? Is the condition chronic and slow or acute and fast? And so on.

      If you have an established stand, I would first treat it with any good systemic fungicide this time of year. I would also remove all decaying material around the plants, including leaf litter, moss, etc. Put down an inorganic mulch such as fine gravel to prevent rain splashing dirt on the plants. Make sure that all dead and or diseased growth is removed, including new growth. In the late summer or fall remove the plants and clean them thoroughly of soil and decaying or diseased tissues. Give them another good soak in a fungicide bath and replant in a new area a good distance away with completely new compost.

      You can also consider applying biological agents such as Bacillus subtilits ( for example Serenade ASO) or mycorrhizal fungi (there are number on the market) to try to create a more balanced growing condition for your plants.

      Tom

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