For nearly 50 years, Old Westbury Gardens has prepped pretty perennial plants — many straight from its greenhouses or elsewhere on Long Island — for an annual spring sale.

The three-day event kicks off at 10 a.m. on Friday, May 5. Believed to be one of the largest and longest-running on Long Island, it attracts more than 1,000 visitors to the lavish 100-acre property.

“This year’s focus is on perennials that we grow at Old Westbury Gardens that might be difficult to find in nurseries, such as delphiniums and foxgloves,” says director of horticulture Maura Brush. Stock for the sale, she adds, will include “some of our favorite annuals with lots of emphasis on plants for shady gardens.”

Each day a mix of perennials, annuals, vines and herbs will be available for purchase. A limited number of heirloom tomatoes also will be sold. This year, the Spanish Lavender plant — a returning favorite — will be available in abundance to accommodate the demand, Brush says.

Most of the plants at Old Westbury Gardens’ plant sale will cost between $9.99 and $17.99. Spring annuals in 4-inch pots will be priced at 99 cents each.

Members of the horticulture team are always on the lookout for interesting cultivars and plant species, Brush says.

advertisement | advertise on newsday

“I think the varieties that we grow and offer are exciting because we have such a well-curated collection,” Brush says. “They are not exotic, necessarily, but a little unusual or special.”

Master gardeners from the Cornell Cooperative Extension will provide free soil testing throughout the weekend.

A large part of the appeal of this plant sale and others like it on Long Island is the reasonably priced and out of the ordinary offerings, horticulturists say.

“Plants are an affordable luxury,” Brush says. “I have never known anyone to regret buying plants or flowers.”

WHEN | WHERE 10-5 p.m. Friday, May 5-Sunday, May 7, at 71 Old Westbury Rd., Westbury. Cash, checks or credit cards accepted.

INFO 516-333-0048, oldwestburygardens.org

ADMISSION $12 ($7 ages 7-17) includes grounds

Farmingdale State College

The college’s agriculture program promises to deliver the unusual — rare geraniums, elephant ears, caladiums, hibiscus, fuchsia, pentas, cuphea and coleus.

Over the course of three days, the sale, which has been held regularly for several decades, has typically attracted as many as 2,000 people, says Jonathan Lehrer, chairman of the college’s department of urban horticulture and design.

advertisement | advertise on newsday

Fifteen varieties of tomatoes and five peppers will also be prominently featured, along with cucumber, eggplant and kale seedlings. Many commonly used herbs such as rosemary and basil will be available on each day of the sale. All small transplants are $3 with larger, 6-inch pots priced at $5.

Flowering annuals and tropical plants will make repeat appearances. An assortment of perennials and shrubs such as hostas, astilbe, phlox, azaleas, rhododendrons and bleeding hearts will be offered. Many are priced less than $10. Traditional cactuses, succulents and houseplants are sure to entice even the novice planter, organizers say.

The majority of the plants at this sale are from Long Island and a vast number are grown by the horticulture department in its greenhouse complex, Lehrer says.

Proceeds from the sale benefit the horticulture students and the college’s Robert F. Ench Teaching Gardens, says Lehrer, who organized the event.

“We have many repeat customers every year,” he says. “Most patrons rave about the prices, selection and plant performance.”

advertisement | advertise on newsday

WHEN | WHERE 9 a.m.-5 p.m. Tuesday, May 9-Thursday, May 11, at the horticulture greenhouses, 2250 Broadhollow Rd., Farmingdale. Cash and checks accepted.

INFO 631-420-2113, farmingdale.edu

ADMISSION Free

CLARK BOTANIC GARDEN

The Albertson garden presents its 48th annual spring plant sale Friday, May 12-Saturday, May 13, with annuals, perennials, herbs, trees, shrubs, vegetables and plants in hanging baskets.

For the first time in the sale’s history, the garden is partnering with local farmers to feature organic, locally grown produce on both days of the sale. Plant lovers can also visit the on-site gift shop and stroll through the art gallery and enjoy refreshments in the tea room.

WHEN | WHERE 10 a.m.-4 p.m. May 12-13 at 193 I.U. Willets Rd., Albertson. Cash or checks accepted.

INFO 516-484-2208, clarkbotanic.org

ADMISSION Free

LONG ISLAND HORTICULTURAL SOCIETY

Planting Fields Arboretum will host the Long Island Horticultural Society’s plant sale on May 21, marking the first time the event is open to the public.

“This is a major fundraiser for us and we needed greater exposure to getting to the people of Nassau County,” says Barbara Loechner, the group’s president.

Annuals, perennials, herbs and heirloom vegetables will be available for purchase. Most of the plants come straight from the gardens of society members and all will be priced with one goal in mind, Loechner says: “We just try to be cheaper than Lowe’s and Home Depot.”

WHEN | WHERE 11 a.m.-3 p.m. May 21, Greenhouse classroom of Planting Fields Arboretum, 1395 Planting Fields Rd., Oyster Bay. Cash or checks accepted.

INFO 516-922-9210, plantingfields.org

ADMISSION Free, $8 per car parking fee