La Nina is at it again.
The ocean-atmosphere phenomenon that originates in the eastern Pacific Ocean off the west coast of South America near the Equator has helped keep the jet stream — and typical winter-like temperatures — on a west-to-east path over Canada.
One of the places where the evidence of La Nina is showing up in the United States is in residential landscapes, especially in some parts of the South where bulbs such as daffodils that are commonly associated with early, middle and late spring blooming cycles were in flower in January.
Should gardeners be concerned? What will happen if there is a sudden drop in temperatures to below freezing or a plunge into the teens?
Don’t worry, says Jay Hutchins, general manager of Brent and Becky’s Bulbs in Gloucester, Va. As long as the bulbs were planted in the fall and have developed roots, they will be fine.
And many, he points out, have been in the ground for much longer than a season.
“Mother Nature has designed them to take a beating,” he said. The reason “they can take more harsh conditions than people think,” he explained, is because “the cell walls of the bulb are flexible and the bulb won’t crack or collapse” during freezes.
The foliage and flowers could be another matter.
Freezing temperatures could “burn” the foliage and cause it to have yellow tips. Extreme low temperatures could cause the buds that haven’t opened to abort as a way of protecting the bulb, Hutchins said.
If the forecast does call for harsh changes, Hutchins offered several tips for homeowners to protect foliage and blooms.
Add extra mulch.
Cover foliage, buds and flowers with milk cartons.
Put up stakes and drape a tarp over the plants to keep a heavy frost off of them.
The unusually warm winter is also presenting challenges for botanical gardens that have planned major spring events. “The spring bulbs are further along than we might like to see,” said Amanda Campbell, manager of the Display Gardens at the Atlanta Botanical Garden.
She is keeping a close eye on the weather because Atlanta Blooms, a huge spring promotion, is planned around blooming meadows of tulips, daffodils, hyacinth, crocus and other bulbs. The tulips are of particular concern because the unusually mild temperatures have caused tulip foliage to emerge several weeks ahead of schedule.
February and early March in the South have been known to be quite cold and nasty, Campbell said, and if the temperatures drop the bulbs will slow down and bloom will be delayed. Her biggest concern would be if Atlanta gets one of its notoriously late freezes after an extended warm period. “That would be very hard on the tulips,” she said.
Home gardeners would have a much easier time. If there is a dramatic turn in the weather, they could just cut their flowers, bring them inside, put them in a vase and enjoy the blooms and the fragrance.
And they can rest easy knowing that, La Nina or not, they won’t lose their bulbs to the whims of nature.
Image above: Tulip bulbs began emerging at the Atlanta Botanical Garden in January, several weeks earlier than expected. (Photo: Tom Oder)