Amaryllis Won’t Bloom? Daffodils Not Flowering?
“ Why won’t my amaryllis re-bloom?”
If only I had the proverbial dime for each time a reader wrote to me – at the New York Times, at Yankee, at (oh distant past) McCall’s – asking that question, I’d be rich. And if there were also dimes for “ why didn’t my daffodils flower?” Bill Gates would have to look to his laurels.
Answers were and are mostly about getting enough sun on the leaves that feed the bulb. Flowers for next year are already formed when these bulbs go dormant, so the stronger they are at that stage, the better the flowers will be. Good drainage is also essential, especially while the bulbs are leafless. And they prefer near-neutral soil, though they can make do in most cases.
Wet or very acid soil, shade, leaf-braiding and cutting leaves before their work is done are the most likely suspects when amaryllis or daffodils won’t flower. But there’s also another culprit that gets a lot less attention: the narcissus bulb fly, Merodon equestris.
It looks and sounds a lot like a bumblebee. It is or can be present anywhere narcissi are grown. Its larvae are what do the damage, entering the bulb from the basal plate and literally eating its heart out. Because they’re deep inside the bulb, you don’t know you have a problem until it’s too late.
And you may not know even then, because damaged bulbs can still send up a few leaves and some of them even recover enough to bloom again – in 4 or 5 years.
After spending several months eating and growing, the bulb fly larva exits in early spring, pupates in the ground and emerges about 2 weeks later as an adult. Soon the females lay eggs, usually one or two to a customer, at the base of inner leaves as near as possible to the neck. When they hatch, the tiny larvae crawl down to the bulb, feed on the base for a while, then eat their way in and here we go again.
Since each female can lay anywhere from 40 to 100 eggs, it really pays to stop the flies before they get well started. But
isn’t easy. The fly has few natural enemies and even the strong poisons no one in their right mind would want to use aren’t terribly effective.
Catching the adult flies is tricky. First you have to recognize them.
Photo by Whitney Cranshaw, Colorado State University,Bugwood.org
They’re easy to mistake for bumblebees unless you’re close enough to see that the legs don’t dangle when they fly and there’s only one pair of wings (bees have two), but low clumsy-looking flight patterns and a complete disinterest in flowers should set off warning bells.
Like all flies they’re hard to sneak up on; make sure you don’t cast a shadow. Then whap straight down with a fly swatter or insect net. They fly up to get away and if you come at them sideways they usually escape. And they’re tough. No matter which weapon you use, be sure they’re dead before calling the job done.
If you have something else to do with yourself on spring days when the sun is shining, you can try diatomaceous earth. A heavy dusting at ground level can discourage egg-lying and if a newly hatched larva encounters it that will take care of that.
Covering the planting with reemay or another barrier is sometimes recommended, presumably for daffodil fanciers who are thinking show bench, not landscape. I wouldn’t put it in the garden but do intend to use it this year to protect the amaryllis.
They summer outdoors in the vegetable garden and have never been much bothered even though their exposed necks make them extremely vulnerable. Every once in a while I’d lose a bulb but it didn’t strike me as a big deal. The daffodils, narcissi, hyacinths, tulips and lilies, all potential targets, seemed to be doing fine. But this winter there were 4 victims out of two dozen bulbs.
Too many. Those larvae are toast, needless to say, but I’d be a fool to ignore the warning. The d.e.is going out too, and I plan to keep a swatter handy.