Few plants give as much pleasure as Erythroniums. Given that they grow in northern temperate regions from Europe across Asia to Japan, and coast to coast in North America there is a wide choice. Two in particular have settled down in our garden. Erythronium californicum “White Beauty” is vigorous and clumps up rapidly by division. Erythronium revolutum is equally pleasing, and has started to seed itself around, which in any other genus I would be thinking of thinning out a little.
Shown here is George Elder's plant of Erythronium helenae that received a Certificate of Merit at the Midland Show in 2006.
When my wife Pat and I look back, the first Erythronium that came our way was Erythronium helenae through AGS seed in 1990, which was not long after we had joined the Alpine Garden Society. Moreover it was random seed, and truth to tell we knew little about alpines at the time. Arriving late it was sown in a 50:50 mix of John Innes and grit at the end of February and germinated a year later at the start of February 1991. Three seeds germinated and we kept them in the same pot for a few years, before moving them on to a 15cm pot. It flowered for the first time in 1998 (it is not unusual for Erythroniums to flower from seed after five years, but helenae is slower).
By then we were a bit more savvy about the right conditions. Erythronium helenae has a limited range in California and Oregon, where it is a woodland plant. So every year we re-pot in a woodland mix of equal parts composted bark, John Innes and multipurpose compost in September (when most of the other bulbs have been done). We keep the pot between the carport and a fence (with other shade lovers), which gives a measure of protection from winds and frost, but is still open to the rain. It does not get a lot of direct sunlight, as it faces north. In these conditions it has slowly increased (it does not have an extensive root system), and now occupies a 25cm plastic pot.
I am always surprised how deep it prefers, but the elongated corms are only a few inches from the bottom. Every year it comes into growth in February and starts to flower from the middle of March to the start of April (which suits our Ulster and Dublin Shows). The flowers last a long time – three weeks – and the top flowers (which open first) are still in good condition when the bottom ones open. Talking to Scottish friends it seems to be a more difficult plant there. Here in Bangor in Northern Ireland we are certainly milder near the sea, but over the years we have had temperatures down to ten degrees below freezing. Such conditions are of short duration however, and I doubt whether the pot has ever frozen down to the bottom.
It has proven a good show plant. The spring of 2006 was exceptionally cold and as you can see not all the flowers (17 by now) had opened by 8th April. Erythronium helenae still managed to get the best plant in Show in Dublin, as well as best from North America.