Plant sales pop up in Maine like dandelions in springtime.

Most of them are fundraisers for good causes. The money that buys some hosta or a bunch of day lilies ends up paying for historic preservation projects or community beautification programs.

Here’s a look at some of this year’s sales. A more comprehensive list is at right.

TATE HOUSE MUSEUM HERB AND PLANT SALE

Last week, volunteers at the Tate House Museum in Portland were potting plants for their annual sale and enjoying the spectacular royal blue blooms of scilla.

“Right now, it almost looks like a blue stream going through the garden,” said Ginny Bishop, one of the volunteers.

The Tate House was built in 1755 for Capt. George Tate, a senior mast agent for the British Royal Navy. It has a historic garden that contains heirloom plants that would have been found in an 18th-century garden and used for medicinal and culinary purposes as well as for fragrance.

The museum’s annual herb and plant sale, held the same weekend every year, helps maintain the garden.

“It’s where we get our seed money, literally,” Bishop said. “It’s very important.”

The sale paid for a new automatic irrigation system that was installed in the historic herb garden last year. Every herb had to be raised and re-planted, Bishop said, and for the first time in the history of the museum, some of the historical plants were sold. The volunteers sold several hundred more plants than usual that year.

“So this year we have decided that we will be thinning the rest of our collection,” Bishop said. “We have a lot of things that, because they’re old-fashioned varieties, they grow very profusely, and they grow better if they’re thinned out a little bit.”

There may also be a few heirloom roses for sale this year, unusual varieties on original stock that are hard to find.

The May 18 sale will also include some day lilies from the museum garden, common and modern varieties of herbs, and lots of plants donated by volunteers and members of the museum as well as Broadway Gardens.

During the sale, which will be held from 9 a.m. to 2 p.m., the museum gift shop will be open, and anyone who buys plants can tour the Tate House at a discounted rate.

COASTAL HUMANE SOCIETY 11th ANNUAL PLANT SALE

The Coastal Humane Society’s plant sale has an ulterior motive.

Sure, they want you to pick up a bleeding heart. But they also hope you have one inside as well, because one of the objectives of this plant sale is to find homes for dogs, cats and maybe a couple of rabbits.

“If somebody falls in love with one of the animals we have at the sale, they can adopt right then and there,” said Jane Siviski, marketing and development coordinator for the Brunswick-based organization. “They can totally leave with plants or kittens or whatever they fall in love with.”

Siviski has high hopes for this year’s sale, which is in its 11th year and will be held 9 a.m. to 2 p.m. May 18 and 19. The humane society has claimed a prime spot just off U.S. Route 1 — 190 Pleasant St., a location that is much more highly visible than sale locations in the past.

Most of the plants have been donated by 15 to 20 nurseries and small garden stores. About a quarter of them are being contributed by a resident of Whitefield, Siviski said. There will also be a cookout, bake sale and raffles.

The star attraction, though, will be the adoptable animals.

So think about taking home a puppy along with your peonies.

LONGFELLOW GARDEN CLUB SPRING PLANT AND PIE SALE

If you’re the kind of person who likes to hit two or three sales in a day, start with the Longfellow Garden Club Spring Plant and Pie Sale in Portland.

It begins at 8 a.m. May 18, and although it goes until noon, most of its business is done before 10. After that, a lot of its customers have headed off to find other sales.

The sale, which will be at the North Deering Congregational Church, is the only fundraiser for the Longfellow Garden Club, which helps tend the famous garden at the home of Henry Wadsworth Longfellow.

“We do have what we think was an original lilac to the Longfellow garden, so every year we take off some shoots and pot them up and overwinter them and then sell them at the plant sale,” said Imelda Schaefer, who is in charge of maintenance at the Longfellow garden. “Not very many — maybe only two or three — but it’s something that we want to continue doing from the lilac that we have.”

Plants that do well in the garden and start spreading get thinned and are brought to the plant sale. Other plants are donated by members from their own gardens.

The sale also features a green elephant table where gently used garden tools and other items are up for grabs.

And then, of course, there are the pies.

FOURTH ANNUAL PERENNIAL AND HERB SWAP

Short on cash, but you’d still like some new plants?

Bring some of your own established plants to the June 13 perennial and herb swap at Spectrum Generations Coastal Community Center in Damariscotta, and swap with one of the other gardeners there. The only cost will be a plant — the community center asks that you bring an extra plant for its own garden.

If you’ve never been to a plant swap before, here are some tips from the community center:

Dig and divide your plants, and place into pots. Milk cartons or yogurt containers work well.

Bring a picture of the plant if you have one, so the gardener you swap with will know what the plant will look like this summer.

Make a sign on poster board of what you have to trade and what plants you’re seeking.

You can trade out of the back of your car or truck. Park at the back of the community center’s parking lot at 521 Main St. and pop open the trunk or tailgate. Some gardeners bring wagons so they can circulate among other traders.

If you’re a new gardener and have nothing to trade, don’t be discouraged. Gardeners are generous folks, and you could go home with a trunk full of new plants. In exchange for the plants, the community center asks new gardeners for a donation of at least $4 per plant.

If you’re bringing plants, don’t bring any to sell. Just bring an extra one for the center’s perennial beds, which get sun throughout the day.

Staff Writer Meredith Goad can be contacted at 791-6332 or at:

mgoad@pressherald.com

Twitter: MeredithGoad