The Longest Blooming Perennial of All!

Larry Hodgson has published thousands of articles and 65 books over the course of his career, in both French and English. His son, Mathieu, has made it his mission to make his father’s writings available to the public. This piece was originally published in the magazine Garden Centrals in May 2012.

The older I become, the more I appreciate plants that cover the entire blooming season. Yes, I have grown and still grow lots of plants with a two or three week blooming period and enjoy trying to mix and match them with others with different blooming periods so my garden is always in full flower right through the growing season. However, you simply can’t beat a plant that blooms for two, three, four months or more to help give your garden a solid base of continuous colour. But there aren’t many plants out there that really bloom from spring through fall.

Of course, there are annuals, most of which have an incredibly long blooming period, but they’re not in bloom in the spring and, worse yet, you have to replace them yearly. I still plant many types of annuals, but I prefer more permanent plants. There are no everblooming bulbs or trees (at least not for cold climates) and precious few shrubs, although Daphne x transatlantica comes awfully close, blooming for me from May to November in the years the Zone 6 (USDA zone 5) plant doesn’t get too severely blasted by my Zone 4 (USDA zone 3) winters. Among blooming plants, that leaves perennials.

Everblooming Perennials?

Now, if you ask most gardeners about everblooming perennials, they’ll mention gaillardias, coreopsis, a few geraniums (Geranium ‘Gerwat’or Rozanne is pretty incredible), some daylilies and maybe malva and nepeta. All are great summer flowerers that continue well into fall. But… where is their spring bloom? Absent.

One of the rare long-blooming spring-flowering perennials is helleborus, but although it starts early enough, it’s all bloomed out by late June or early July. In fact, I’ve only found one family of plants that includes perennials blooming from spring through fall, the Fumariaceae or bleeding heart family.

Better clones of the western bleeding heart (Dicentra formosa) and the fringed bleeding heart (D. eximia), plus hybrids between the two species (D. ‘Luxuriant,’ D. ‘Adrian Bloom/ D. ‘Aurora,’ etc.) are remarkably long- blooming, blooming massively in late May/early June, and then sporadically right through summer and early fall. Better yet is the yellow corydalis, Pseudofumaria lutea, formerly Corydalis lutea. It starts blooming a few weeks earlier than its relatives, the bleeding hearts, and continues just as long, into October. But even it is beaten by an even closer relative, white corydalis.

And the Winner Is…

White corydalis (Pseudo-fumaria alba, formerly Corydalis ochroleuca) is up and blooming by mid-May in my climate, flowering along with the mid-season daffodils and tulips, and sails through the summer into October without stopping. November can be an iffy’ month where I live, with freezing nights and the first snows, but it keeps blooming right through them all. The blooms don’t even seem to be damaged after a day or two under 10cm (4″) of snow.

What does stop it is when either the ground freezes solid or a long- lasting snow, one that will last until spring, settles in. Lasting snow usually arrives in mid to late November in my climate, but there are years when it comes late and the plant is still blooming in December. I’ve been told that it will bloom 12 months a year in climates where winters never include more than moderate frosts. Now that’s a long-blooming plant!

Pretty as a Penny

This favourite is long-blooming and attractive, too. While not a show- stopper (the flowers are too small and their clusters too thinly spread for that), it’s pretty at all times. The blooms afe borne densely on short spikes raised just above the foliage and appear creamy white from a distance. Up close you can see their unusual shape – generally tubular, but opening into lips with some yellow peeking out at the tip, while there is a green spot on the outside. As one spike fades, others take its place and this continues until the ground freezes solid or the snow settles in. The foliage is attractive, too: finely cut, fernlike and grey-green, perfectly setting off the flowers.

The plant is small to moderate in size, about 15-45cm (6-18″) in height and about the same width.

Good Care Means No Care

And did I mention that it’s easy to grow? Sun or shade seem to work equally well as long as the plant gets some spring sun, and any soil will do as long as it is well-drained, even alkaline soils. It positively thrives in dry shade where so few plants do well. I’ve been told it can go summer dormant in hot, dry climates when planted in full sun. If that describes your summer conditions, plant it in shade. Elsewhere, full sun is fine. It requires no pruning, deadheading, staking nor any other persnickety care, nor does it seem to have any insect or disease problems. Just plant it and let it do its thing… which includes self-sowing.

Yes, It Does Get Around

It’s not one of those invasive plants that crushes its neighbours, but rather pops up here and there, filling in open spaces. If you like formal plantings where every plant remains in its designated spot, simply don’t plant white corydalis. It is just not that kind of plant. However, it is a plant you’ll adore if you like English-style mixed beds or naturalized woodland gardens. It also likes rocks and has sown itself into a few retaining walls at my place. And thank goodness for that! Planting in rock walls is such a pain that I love plants that do it on their own.

And you do want the plant to selfsow, as it is not long-lived. I’ve been told that individual plants rarely live more than three or four years, but I’ve never had to notice, as there are always enough replacements in about the same spots that the death of a specimen or two doesn’t show. And it can only be propagated by seed – fresh seed. The best way to share plants with a friend is to pot up any stray babies.

Now the real downside: white corydalis is hard to find in nurseries. But do ask. You’ll be surprised at how many have it in their display gardens but have never bothered to pot it up.

So there you go! White corydalis is simply the bloomingest perennial ever and so easy to grow. Try it and see!