Season-extending plants

Keeping the color
Jim Jonker at Jonker’s Garden in Holland, Mich., grows perennials throughout the summer. He also stores Asiatic lily bulbs in a cooler, planting them three to four times a year to offer his customers. “If someone sees a pot with color, they’re going to snatch it up,” Jonkers said.

To ensure he has plants available, he sows seed of several different species with dianthus, rudbeckia and vinca working well for him. He offers most of the plants in 6-inch pots, with some 4½-inch. Heat-tolerant plants such as Diamond Frost euphorbia, mandevilla and purslane have been good sellers.

All of the plants are produced in naturally-ventilated greenhouses with shade cloth and drop sides. Jonker said he found growing the plants with natural ventilation tends to “harden” them up.

This year Jonker didn’t open as many greenhouses, instead choosing to buy product from other growers because of plentiful plant availability in Michigan. His total production area was reduced from 40,000 square feet to about 25,000 square feet.

“We still grow some of the more unusual or harder to find items like mandevilla on trellises,” he said. “Even though we’ve always been a grower-retailer, we decided to try buying this year.”

Jonker’s Garden grows and sells house plants, annuals, perennials, trees and shrubs.

For more: Jonker’s Garden, (616) 392-7234; www.jonkersgarden.com


Petunia PinstripeTrial and opinion
McLain Greenhouses in Estancia, N.M., continues offering its spring varieties during the later summer months.
“But, we offer them in 6-inch pots, up from 4½-inch pots,” said Milton McLain.

McLain said he picks plants that are going to survive--plants consumers can buy, plant and have survive in their gardens. Species that do well for him are lantana, angelonia and petunia. He said petunias do well in the heat because of the low humidity. McLain is currently trialing Ball Horticultural’s new Black Velvet and Pinstripe petunias.

“Pinstripe is actually doing better than Black Velvet. It has yellow pinstripes that make it distinctive and stand out more,” he said.

McLain receives samples from Ball and EuroAmerican Propagators each year to trial in his company’s gardens. He tries to do single variety plantings as well as combinations for the August open house he holds for his customers.

“Sunsatia Cranberry Improved nemesia is very attractive,” McLain said. “I think it’s going to sell really well because it has an amazing fragrance to go with it. That’s unusual these days.”

Other crops grown by McLain in his 75,000 square foot greenhouse include spring annuals and pansies, mums, kale and poinsettias in the fall.

For more: McLain Greenhouses, (505) 384-2725.

Cut flower bonanza
Tom McElroy at Newton Greenhouse in Newton, N.H., starts flowering fall garden mums early to get a jump on sales at a time when demand would otherwise be slow. He grows gerbera daisies in both 4½- and 6-inch pots. Hibiscus is another plant he relies on to extend summer sales.

“Demand for plant sales have dropped dramatically due to the intense heat,” McElroy said.

In order to increase consumer interest and his income, he is growing fresh cut flowers including zinnia, celosia, dahlia, snapdragons as outdoor crops along with an indoor crop of lisianthus.

He is currently growing gloxinia with good success and looking at lisianthus from France. He said ornamental peppers in 4½-inch pots have done well in the heat.

“If you grow the same old thing, it’s hard to compete,” he said.

One cut crop that has done well this summer is Benary’s zinnias. Because of the heat and little rain, McElroy said he has not had to be concerned with fighting foliar diseases as in past summers.

Newton Greenhouse produces holiday crops including poinsettias though in reduced numbers. “They’ve become too much of a commodity with not enough profit,” McElroy said.

Cut flowers, tulips, anemone and ranunculus are also grown in 53,000 square feet of covered greenhouses and 1 acre of outside production. 

For more: Newton Greenhouse, (603) 382-5289