Spring Bulbs Poking up—in Winter!
Q. In November I planted iris bulbs and covered the ground with mulch as was directed on the package. It is now the end of December and the irises have sprouted up about 2-3 inches above the mulch. Will this be a problem for the bulbs? I wasn't sure if a really cold spell would damage the bulbs now that they're sprouting. I am fairly new to bulbs, but I planted giant alliums last year and they did not begin sprouting until the spring.
- ---Laura in Quakertown Pa.
- ---Judi in Cincinnati, OH
- ---J. in Bucks County
Now, as we have mentioned previously on the show, it is perfectly normal for the skinny, floppy, completely unattractive octopus-like 'leaves' of grape hyacinth to pop up in the fall and lay prostrate on the ground in their non-glory all winter until the fabulous little flowers that follow finally brighten up the show in the Spring.
But it is UNnatural for other Spring bulbs to send up their shoots before the New Year, so we decided to consult with someone who routinely tricks spring bulbs into doing things they normally would not: Art Wolk, two-time Grand Sweepstakes bulb forcing champion at the Philadelphia Flower Show and author of the great new book "Bulb Forcing for Beginners and the Seriously Smitten". (Available directly from Art at HIS WEBSITE).
"Yes, it's crazy out there right now," agrees Art, who postulates that the sustained cold spell much of the East Coast experienced in October has caused lots of Spring bulbs to behave "almost like they're being forced. A really cold month early in the season followed by a very warm stretch can trigger flower stem extension a month ahead of the normal time, which is a lot like what I do deliberately and artificially to get bulbs to bloom ahead of schedule for the Flower Show."
So is that what's going to happen? Are Spring bulbs that normally bloom in April going to bloom in March? Or will winter storms kill the flowers first?
"It's all good news," reports Art. "First, there's a lot of antifreeze in these plants, so like the grape hyacinth, they can survive just fine with their leaves above ground over winter. And, more importantly, flower stem development occurs independently of the leaves. Those little Iris reticulata your first listener is worried about need seven to nine weeks of temperatures in the 38 to 50° F. range to begin extending their flowering stem towards the surface, no matter what the leaves are doing."
But seven weeks doesn't seem that long a time, I note—don't some tulips need twice that long? "Absolutely," replies Art, reminding me that those beautiful little Iris bloom very early in the Spring, and so they have among the shortest times necessary for stem extension. "Most of the bulbs I force for the Flower Show—like daffodils and tulips—need at least 10 weeks of cold temperatures before they shoot that flower stem up. And the bulbs that bloom the latest in Nature—like those big ornamental alliums—take even longer.
"Now, we shouldn't underestimate what a crazy climate-change season this has been; my friend Ellen Spector-Platt posted a picture on her blog of snowdrops in full bloom in New York's Central Park in mid-December (http://www.gardenbytes.com)—which seems crazy! But because snowdrops are among the very earliest of Spring bulbs to bloom, it really just means that they were four to six weeks ahead of normal.
"So tell everyone who has greenery up already not to worry, and not to do anything to try and 'help' the bulbs. They may bloom a month earlier than usual, or they may bloom pretty much on schedule if it takes the soil an especially long time to warm up in the Spring, but they should bloom just fine. The leaves are tough and the flowers are still safe inside the bulbs.
Just warn people especially not to cover them with a lot of any kind of mulch to try and protect them. They don't need any help, and I've seen frozen mulch do a lot more damage to emerging flowers than weird weather ever could."