The secret to growing sweet blueberries on the Vineyard is patience and sun.

Susan Murphy will open her farm in Chilmark to the public this year. — Ivy Ashe

“I say this every single chance I get,” blueberry farmer Susan Murphy said while standing next to one of her bushes this week. “High bush blueberries turn blue 10 days before they’re ready to pick. What makes them sweet is the action of the sun on the fruit ­— it increases the sugar content.”

The cultivated blueberries at Mrs. Murphy’s farm in Chilmark are just beginning to turn a light shade of blue, darkening by the day as the sugar content increases. The bluetta variety will be the first to be harvested, sometime around Bastille Day, or July 14, she said.

“Bluettas are the earliest and always consistent,” she said. “Then I get the Bluerays, and after that the rest of them don’t know they’re supposed to come in progressively. They all come at once — my Berkleys, Jerseys and Covilles. The Covilles are supposed to be September ripeners but they don’t understand that. Everything gets mixed up in August.” Mrs. Murphy and her husband Lynn planted their blueberry bushes in 1986, when the couple purchased the small piece of property in order to save it from development. They decided blueberry bushes would be the perfect answer.

“We really knew nothing about farming or plants or any of those things,” Mrs. Murphy said. “It was really learning while we were doing.”

Tending to blueberries begins in the winter months when Mrs. Murphy diligently prunes the bushes. The temperature must be below 42 degrees when the bushes are dormant.

Lowbush blueberries at land bank's Trade Winds property. — Ivy Ashe

“Ironically it’s the thing I like most about farming,” she said. “It’s so peaceful and you have to get dressed, you have to go out, you have to sit on the ground and you have to be cold, but it feels so good. It gets me outside all the time.”

“I don’t need a Stairmaster, I don’t need a Nordic track — I have my blueberries,” she added.

Bushes should be no taller than six feet and should be trimmed from the bottom up.

“You go for the thicker stalks and you cut them right to the ground and what that does is stimulate the plant to send up new shoots,” she said. “You want to prune so you get good air circulation....much taller than six feet you really can’t pick them. A blueberry bush will overproduce, so by pruning you’re making fewer berries but bigger berries.”

Blueberries come in high bush and low bush forms, though stem from the same family. Wild low bush blueberries are now ready to harvest (some even say they’re higher in antioxidants).

“Low bush is almost like a ground cover, the berries are very tiny and you pick them in a different way,” Mrs. Murphy said. “They’re very scrubby. You don’t prune them, you burn them. It’s a totally different means of cultivating.”

Though smaller, some say lowbush blueberries are higher in antioxidants. — Ivy Ashe

Mrs. Murphy covered her bushes with green nylon tulle last week to deter flying birds from eating the fruit, though turkeys are still known to stick their heads up in the netting and peck away. Small worms can also be a pest, but netting helps keep the berries relatively pest-free. The berries are grown organically.

In the early years of blueberry production, the ridge used to be covered in multi-color tulle. “I had pink and yellow and ivory and blue, all these colors and the bushes were smaller then,” she said. “It looked like a prom. It looked like the vestal virgins swaying in the breeze. Then I discovered that green nets fool the flying birds, they don’t like to feel tangled up. Once they get word the bushes are netted they’ll leave them alone.” Mrs. Murphy buys her netting from the Fabric Corner in Falmouth, though many fabric stores carry the green netting. She then uses clothespins with wire springs to attach it to the branches.

“A farmer can do just about everything . . . but in spite of your best efforts something makes it not happen right,” Mrs. Murphy said. “Farming is a very humbling experience because you realize how much is not in your control.”

Crop yields vary year to year, depending on weather, pollination and other variables, but Mrs. Murphy recalled a banner year in 2008.

“That was the year everyone had fruit on everything,” she said. “It was almost overwhelming the number of berries I had. I had four people picking for 45 minutes on one bush. It was just incredible.”

Highbush blueberries, plump and ready for picking. — Ivy Ashe

“When things are right they will produce their hearts out,” she added.

Blueberries are ready to pick as they turn a deep blue with a slight sheen to them.

“You know when they’re ready because they will just about fall off in your hand,” she said. “You won’t have to tug them off.”

At the top of the hill Mrs. Murphy checked on the bluettas. Some had red coloring around the eye of the berry, an indication that they weren’t ready to pick. But a few had just turned the right shade of blue.

“Try these,” she said, popping one into her mouth. She paused. “Almost there.”

Potential pickers can call the Murphys after July 14 to schedule a pick-your-own visit to the farm at 508-645-2883.

Pollorum Testing For all potential poultry entrees into the Martha’s Vineyard Agricultural Fair, the state department of agricultural resources will be on the Island conducting pollorum testing on July 16 and July 23. Testing is free and mandatory to exhibit poultry at the fair. Contact Alex MacDonald at 617-0872-9961 or alex.macdonald@state.ma.us or Megan Megrath at 617-626-1798 or megan.megrath@state.ma.us.

This column is meant to reflect all aspects of agriculture and farm life on the Vineyard. Remy Tumin may be contacted at 508-627-4311, extension 120, or email her at rtumin@mvgazette.com.