RICHARD ALLEN, of Leland, poses in his garden with his bibb lettuce, greens and spinach plants. There’s a few things you can’t do before Memorial Day in Michigan — wear white, fish for bass and put your annual plants in the ground.

While a couple weeks of unseasonably warm weather this spring may have had some folks itching to get their hands dirty, it’s always a good rule of thumb to wait, as many plants can’t handle frost, said Pam Bardenhagen, home horticulturalist and master gardener program coordinator with the Leelanau County MSU Extension.

And if plants get too cold, not only will you miss your own home-grown tomatoes and cukes, you’ll lose a chunk of money.

“It’s safest to wait, as you could lose your investment,” Bardenhagen said.

Mike Kiessel of Suttons Bay has been gardening since he was 5. A master gardener, the 52-year-old plants just about everything, including tomatoes, melons, corn and peppers. He keeps track of ground temperatures, watches the forecast carefully and waits.

BIBB LETTUCE, which has been protected from the elements by a cloth canopy, is already growing in Richard Allen’s garden. And he’s never lost a crop.

While Kiessel usually follows the Memorial Day rule, as with every rule there are exceptions. In 2010, which saw an unusually warm spring and summer with the perfect amount of rain, Kiessel says he reaped the best crop of vegetables he’s ever grown. That year he had everything in the ground by May 22.

“This year I don’t know what to think,” he said. “I think I’m going to stick with the Memorial Day rule. I plant too many things to be trying to cover it up.”

Plants like peas, lettuce, radishes, spinach and fava beans can go in as soon as the ground thaws, and garlic can be planted in the fall, but most plants should wait until the threat of frost has passed. That goes for vegetables such as tomatoes, peppers, eggplant, corn and any squashes or melons, as well as annual flowers such as petunias, impatiens, marigolds and bachelor’s buttons.

RICHARD ALLEN, of Leland, preps his yard for a row of tomatoes with an organic com flowers and vegetables, the avid gardener finds plenty of work to do. “Nothing will tolerate complete frost, but colder weather plants can tolerate a little cooler weather,” Bardenhagen said.

Frost can wreak havoc on growing things, whether they’re in a home garden or in an orchard. This year’s early warm weather, which is proving to be devastating to the tart cherry crop, got everything growing about five weeks early. Plants came out of their winter dormancy, with fruit trees blossoming earlier.

mpost he makes himself in his back yard. Though it’s still too early to plant most annual “People are seeing damage to their perennials,” Bardenhagen said. “People who have their peach trees in the back yard may be seeing that they’ve lost the fruit.”

The early blossoming and frost caused damage in two ways, she said. The frost did actual damage to the delicate blossoms, but cold weather is also keeping the bees from pollinating the trees. Bees will only work when temps are above 50 and when there is no rain or wind, Bardenhagen said.

“Bees are only going to fly in certain conditions,” she said.

Richard Allen, of Leland, has a yard full of apple, pear, plum and apricot trees, as well as bibb lettuce, greens and spinach that is already coming up under a cloth canopy that has protected the green shoots from the elements.

An avid gardener for 35 years, Allen does two main plantings in early May and late May.

“If you’re a good gardener and you know what you’re doing, you can be planting way earlier,” he said.

For most people, it’s just better to wait.

But that doesn’t mean there’s nothing to do. Now is the perfect time to plant strawberries, raspberries and blackberries, as well as fruit trees, Bardenhagen said.

“Mid-April to early May is a good time to put trees in the ground,” she said. “They literally just wake up when you plant them.”

It’s also a good time to put bare root trees in the ground. Bare root trees, which look a little like scraggly sticks, are purchased without being potted in soil. Buying trees that way is a more economical way to go, Bardenhagen said, but they do have to be ordered ahead of time because they do not keep and are not found on most local greenhouse shelves. For that reason the trees should be planted immediately after they arrive at your home, she said.

Bardenhagen says annuals purchased from a greenhouse should be “hardened off” before they are planted to get them acclimated to being outdoors. Plants grown in a nursery are not used to wind, direct sunlight or cooler temperatures and should be set out on the porch during the day and brought in at night for a couple of days, she said.

“If you’re taking something directly out of a greenhouse it’s going to have no ability to tolerate the frost,” she said.