It’s March at Longwood Gardens and the Himalayan blue poppy is once again on display in our indoor gardens, turning the conservatory into a dazzling show of sky-blue blooms. Unfortunately, the show ‘Lingholm’ meconopsis puts on lasts for only a short time.
Each flower spike carries three to five buds opening in close succession over six to 12 days, with each individual flower lasting three to five days. Because the blue poppy’s show is such a short one, droves of people are drawn to the display. Considering how excited people get when they see this flower, I often wonder what kind of market potential such a plant might have.
In this article, you’ll find information, cultivation requirements and some of the challenges I experienced working with this plant. Who knows: Perhaps you, too, will be inspired to make it work in your market segment.
Background & Natural Habitat
Meconopsis is a genus within the Papaveraceae or poppy family. Within this genus is a group of plants referred to as Himalayan blue poppies, which include M. betonicifolia, M. horridula, and M. grandis, as well as some interspecific hybrids of these species.
Meconopsis grandis, the national flower of Bhutan, was not so long ago considered a myth. The story of discovery and rediscovery of the different meconopsis species is fascinating and complex, with early reports reaching back to perhaps the 1800s.
For example, a report from 1886 included the discovery of Meconopsis betonicifolia in China. Another interesting story is a failed 1922 Mount Everest expedition during which blue poppies were discovered, as well.
Soon after discovery, plant material was brought to the Western Hemisphere to the delight of horticulturists. This challenging-to-grow plant soon became a mark of distinction for any gardener succeeding in its cultivation.
Blue poppies are rarely cultivated outside their native habitat. However, given the right conditions, they will thrive in gardens located in Canada and the northern regions of the United States, including areas of Vermont, Maine, Washington and Alaska–as well as some locations in Europe.
Generally, blue poppies require areas exhibiting moist and cool conditions. Lacking these climatic requirements in Pennsylvania, I force ‘Lingholm’ in my greenhouses for display in March. I take advantage of the cool growing conditions of the winter months.
In short, growing blue poppies as a mass market item (perennial) would be limited to a narrow geographic area. Forcing them into flower during the winter could provide for very attractive cut flowers–but this would need a lot of product testing.
Post-harvest handling is challenging due to the short shelf life. On the other hand, consumer interest seems to be enormous. Potentially, someone could make a nice bundle of cash after solving the production, post-harvest handling and distribution challenges.
‘Lingholm’ is a cultivar that produces large flowers that are on average four inches in diameter. The substantial petals are of a mesmerizing deep sky blue color. All parts except the flower are covered by fuzzy hairs, adding to the mysterious appeal of the plants. It is a perennial propagated by seed.
Because ‘Lingholm’ is a seed strain, slight variations within a crop are frequently observed. Strain-specific differences include the vigor of individual plants and timing of flowering, as well as flower pigmentation. This genetic variability may be the reason for impurities of flower pigmentation. Some flowers may show a more or less developed mauve to purple tint.
This somewhat unpredictable trait may be intensified by stress, such as sudden changes in temperature, change of pH and fertilizer, or water management issues. Reports of new vegetatively propagated cultivars have been around for a while. However, availability of these new hybrids is still limited, especially in the United States. At this time, ‘Lingholm’ is arguably the best cultivar to work with.
Forcing Himalayan Blue Poppies
For the last 10 years or so, I’ve been ordering one-year-old crowns from Stanley Ashmore’s blue poppy farm in Palmer, Alaska. The plants finish the growing season in Alaska and are exposed to the first frost to induce dormancy. At that time, the plants are harvested and shipped to us via air freight. I normally receive the plants the first week of October.
Upon arrival I immediately transplant the poppies into Band pots (Anderson Die & Manufacturing, Portland, Ore.). It is a good idea to clean any remaining foliage from the crowns while potting. Otherwise they may start rotting or get infested with gray mold–and you don’t want either of these in your cooler.
I like using Band pots because I can fit lots of the square pots onto Cannon carts in the cooler. The Band pots I use are 4 by 4 by 10 inches. Otherwise, any plastic pot that’s just slightly larger than the root balls should work fine.
I pot with Sunshine Mix 4 (aggregated mix), which is manufactured by Sun Gro Horticulture. Make sure the pots are watered in. Blue poppies have a very delicate root system. It is a bad idea to allow the root ball to dry out or to damage it with dry potting mix. Try not to disturb the root ball while potting and make sure the crown is not covered by media. The root ball needs to be completely covered, and the crown should be exposed and level with the surface of the soil.
In my experience, this step causes frequent quality issues–the potting line staff definitely needs to be trained to avoid quality issues. The well-watered pots are placed into a cooler with a temperature set point of 34°F. The plants remain in the cooler for 12 weeks completing vernalization.
Transplanting & Forcing
If your supplier delivered the crowns on time, somewhere around the first week of October, vernalization should be complete by New Year’s Day. At this time, I take the plant back to the potting line. For this step, I use R88 fiber pots (Kord Fiber Grow Products) and Sunshine Mix 4. Particular care should be taken in potting the plants at the right level. Make sure the root ball is completely covered without burying the crown. Unfortunately, meconopsis is a fussy plant, so a 5 to 10 percent loss is normal.
A couple of years ago when Alaska experienced a very warm autumn, plants did not go dormant on time. In order to stay on schedule, they were sent green. I found out very quickly that nature cannot be rushed. I lost more than 50 percent of my crop that year because the still-green plants did not take well to the vernalization treatment in the cooler.
Temperature. The re-potted plants go into the greenhouse. The temperature set points should be 45°F days and 50°F nights. Due to solar gain during the day, the 45°F set point tends to yield an average thermal accumulation of 50°F.
Forcing time is expected to be 60 days based on the 50°F temperature average. Due to the genetic differences in the population, some plants start blooming the fourth week of February, and peak bloom is reached around March 7. Incidentally, this type of response works really well for our display division, although producing a commercial pot crop would be challenging.
Under no circumstance should growers expose blue poppy to temperatures above 70°F for extended periods of time. Even at 65°F, the blue poppy will go into heat stress.
Water. Blue poppies like it cool and moist. Make sure to always monitor the water status of the pots. Never let the pots dry out. Always maintain an even moisture level. The fibrous root system is delicate and quickly desiccates in dry conditions. Stressed plants remain stunted and the pigmentation of the petals changes from blue to a purple/mauve color. On average, I water every two to three days. Watering frequency increases on sunny winter days.
Fertilizer. Blue poppies require a moderately acidic media. Sunshine Mix 4 is indicated to have a pH range of 5.0 to 7.0. Right after potting, I check the pH of the pots and tweak the pH with some aluminum sulfate if needed. I try to keep the pH around 5.7 to 6.2. Peters Professional fertilizer 20-10-20 (The Scotts Company) is a moderate to high acidifying fertilizer. I am careful not to use aluminum sulfate too freely at the beginning of the crop cycle. The plants are fertigated on a regular watering cycle two to three times a week. The pots are flushed with clear water on weekends.
Light. In my opinion, blue poppy benefits from supplemental light and day-length extension. Initially, I was using supplemental light in my greenhouses to push some other crops along during the low-light winter months. Because some sources suggest moderate light levels are preferred by blue poppies, I have not been watching for differences in past years. By chance this year, I ran out of space and had to grow a number of pots away from these lights. The difference in performance could not have been more obvious.
The plants under supplemental light were nearly twice the size of the plants growing under normal conditions. I use 600-watt high-pressure sodium lamps that I programmed via Argus for a 400W/m2 minimum daylight threshold on a time window from 4 a.m. to 10 p.m. daily. Essentially, I extended the day to 16 hours, thus growing a knockout crop.