Garden Culture Of Cypripediums
By Darcy Gunnlaugson
Gardening with Cypripedium is an ongoing exercise in Care and Attention. The following is a brief introduction to this art. But, before you develop a fatal attraction for these plants, please note the following. This is small genus of temperate terrestrial lady's slippers, and, it is not an easy one to grow. Consequently, the novice should avoid tackling the species therein, regardless of how enchanting and tempting they may appear to be. If you are a novice gardener, cease reading at this point.
Garden Information and Tips
The notions of Care and Attention apply absolutely to raising these plants, and they depend in turn upon these requirements from their owners / cohabitators... more so than any other garden variety plants. "Care" therefore should be provided to establish: 1) a suitable growing mix, 2) suitable moisture, 3) a suitable dormant period, 4) a suitable feeding schedule, and 5) suitable protection. "Attention" to these details on a regular daily basis will insure the difference between success and failure,particularly in the first 2 years that they are introduced into the garden.
1) A suitable mix for these species is: three parts pearlite, one part sand, one part clay, and one part conifer forest floor duff (consisting of the decaying upper 1 inch of rotting wood, old needles, humus, etc) This mixture can be modified depending on the particular need of each species, with for example, copious "peat moss" added for species requiring that ingredient, or more sand, clay, etc. added as if to taste. A free draining mixture is normally required and a slight side hill or hummock are advised sites so that wet conditions do not develop.
2) Suitable moisture for these plants depends upon each species, but all enjoy moderate moisture during the growing season, and a cold semi dry dormant period. Some like C. acuale and C.passerinum can be grown in a wet sphagnum bog. Reginae also enjoys abundant moisture. The remainder should be kept adequately moist during the growing season, and only barely moist during dormancy, with rain protection afforded during the dormant months, if rain is a feature of your climate in winter. Lack of protection from rain during dormancy will spell the demise of the plants.
3) A suitable cold dormant period must be afforded these plants, and some like C. guttatum and C. passerinum and other far northern or cold climate species will find it difficult to flourish in milder climes. By contrast, C. formosanum will do well in milder climates and is almost always the first to bloom each spring out of the entire genus (C. fasciolatum and C. taiwananum also bloom at the approximate same time and likewise flourish in milder climes) So, if refrigeration can be provided for the colder blooded species, success with bloom can be assured. This artificial cold, however, is obviously not a garden application. Therefore, where snow and chill temperatures are guaranteed features, the cold blooded species will fair well and the species like formosanum will not live. Having the entire genus represented in one's garden would be a difficult feat and inventive microclimates within a climate that could accommodate the mild end of the spectrum would be an advised location for this attempt.
4) A suitable feeding regime would commence once the plants are unfurling leaves. Dilute liquid feeding of Seaweed Fertilizer, Fish Fertilizer, or commercially available orchid fertilizers like Dynagrow, is advised once monthly. With heavy feeders like C. formosanum, a more aggressive feeding schedule may be employed. Again, attention to your plants will tell you how they are fairing and poor health is usually indicative of too much moisture, too much shade, or conversely, dry conditions, over fertilizing, etc. You can determine what is happening by observing and paying attention, or failing that, you can be responsible for your plants demise.
5) Protection from slugs/snails is advised in the garden setting. Small 3" high hoops of wire mesh can be made to encircle the plants as they emerge, and this will generally forestall mollusks attempts to snack upon the new shoots or stalks. Baiting for slugs is also advised. If in a treed area, root invasion is possible and an artificial plunged bed can be made to
contain the plants. A simple method for this is to excavate the location and line it with plastic. Pierce the bottom carefully with a piece of hose and snake this to an exterior downhill location as a drain. Fill the bottom portion of the bed with rotted wood chunks for moisture absorption then atop this mound your growing mix. Plant, water in, top dress with forest moss, and you're done.
When planting out your divisions or seedlings, note the following:
1) A healthy multi root system with a mature division is imperative, with no short cut roots. The root tips are the only means for nutritional uptake in Cypripedium. They will not grow new ones until late in the season, so short rooted plants are a death sentence. They may bolt as normal from dormancy and begin to unfurl, but then they will develop rot and go over. The rhizome may or may not survive underground when this occurs. Seedlings should have a good root system as well, and seedlings with one or two roots are not likely to survive long. In all cases, both with seedlings and divisions, the roots should be healthy and white, not black.
2) Plant so the tip of the shoot is partially protruding from the soil and cover this with living forest moss. Roots should be spread fan like and downwards before covering. The planting location should be bright shade to sunlit. Full daylong sun exposure is not advised but at least a few hours of sun/partial sun is required.
3) Do not commence watering (keep only just moist) until the plant starts to aggressively grow leaves. Too much moisture early is not good, as are overly moist conditions during dormancy. Dormancy is normally from mid October through March in milder climates, and much earlier and ranges to later in colder locations.
The number one cause of demise to healthy plants is overly moist conditions during dormancy. The number one cause of demise to "apparently" healthy plants is short root tips. You can do something about the former, but little about the latter except complain to your vendor.
The book "The Genus Cypripedium" by Phillip Cribb is the current bible on these plants and one would be advised to purchase it in advance of any purchase of these plants. With it, care and attention, your own abilities and intuition, you just may do okay.