VINCENNES, Ind. (AP) — The calendar may proclaim that spring has arrived, but experts advise against breaking out your gardening duds and flower pots just yet.
Temperatures are expected to rise well into the 60s by Friday, but they won’t stay there, according to the National Weather Service in Indianapolis. Lows will drop back into the 20s and 30s this weekend and remain there into the middle of next week.
“It looks like we’re going to have a later spring than we’ve had in the past,” Jason Puma, a NWS meteorologist, told the Vincennes Sun-Commercial. “Climate-wise, over the next two months, it looks like there’s a good chance for below-normal temperatures.”
“But at least it’s not those negative or single-digit temperatures we have been seeing.”
Generally, the average March high for southwestern Indiana is about 51 degrees and the average low around 32. Things typically warm up in April with average highs at about 63 and lows in the mid-40s.
The last frost for this area usually occurs sometime between April 15 and April 25, but Puma said given the long-range forecast, the risk of overnight frost could last well into May.
Jenny Nettles, the garden center manager at Perk-A-Lawn Gardens, 2470 Maranatha Lane, said in as little as two or three weeks the green houses will begin filling up with annual flowers, things like brightly-colored petunias, begonias and geraniums, but that doesn’t mean people should plant them right away.
“Any frost will hit those harder because they’re more tender,” she said. “Annuals should wait awhile. We usually tell people to plant those around Mother’s Day. By then, we’ve usually had some good weather.”
But, Nettles pointed out, several local landscaping businesses are already hard at work preparing people’s outdoor flower beds. Several perennials are already starting to poke through the ground, somewhat teased by recent warm weather.
And most perennials, Nettles said, will be fine as long as they don’t begin to bloom before winter weather is gone for good.
“We’re going as hard as we can right now,” said Garth Whewell, the general manager at Landscapes by Dallas Foster, 3729 N. Camp Arthur Road. “We have a pretty small window anyway, and this winter hasn’t helped.
“But as far as planting those popular annual flowers goes, it will at least be another month before we would advise that.”
Valerie Clingerman, an educator in agriculture and natural resources with the Knox County Purdue Extension office, said while there isn’t an exact science when it comes deciding the best time to plant flowers and garden vegetables, there are a few guiding indicators people can use.
Most experts agree the last frost in southern Indiana is typically around the end of April, and planting can then begin in early May. But perhaps more important to consider than air temperature is soil temperature, Clingerman said.
For flowers and outdoor landscaping, the “magic number,” she says, is 50 degrees. For gardening, it should be higher, usually at least 60 degrees.
And those numbers, she said, could take awhile to reach this year given the harsh winter weather. The ground is pretty frozen, she said, and will take awhile to thaw.
“It will depend on soil moisture as well,” she said. “If the soil is very moist, the temperature will rise more slowly. And if there is a lot of cover on the soil, like mulch, then that will take longer, too.
“You want to go out and work the soil up in your gardens and landscape areas. That will release the moisture and allow it to dry faster.”
But for those who simply can’t wait until May to beautify the exterior of your home with flowers, there are things you can do to protect them should another frost strike. If temperatures drop below 32 degrees at night, they will need to be covered.
But most people, Clingerman said, do this incorrectly.
“It’s always possible that southern portions of the state could plant by April 15,” she said. “But that does leave a chance that you’ll have to cover them or bring them inside.
“If you can’t bring them inside, cover them with newspaper, old sheets or some kind of paper or cloth material,” she said. “A lot of people use plastic, but plastic amplifies cold air. You don’t want to use plastic. That’s really bad.”
Information from: Vincennes Sun-Commercial, http://www.vincennes.com