by Bill and Mary Weaver
On Oct. 25 this year, at Linvilla Orchards near Media in southeastern, PA, workers were busily picking large red, ripe strawberries. A 26 degree frost had killed nearby tomato plants the night before, but the Seascape day-neutral strawberries, protected overnight by a floating row cover supported by hoops, were in fine shape.
Three years ago, Norm Schultz, Linvilla’s farm manager, obtained a two year, $20,000 Specialty Crop Grant administered by the PDA to work on solutions to production problems peculiar to day neutral strawberries.
Schultz took his responsibilities for the grant seriously, and his work was of sufficient quality that his grant was renewed for 2013-2014 for another $20,000, provided his employer, Linvilla Orchards, devoted a matching $20,000 of their own toward the project, which they did.
Day-neutrals are interesting plants. While traditional June-bearing strawberries initiate flower buds for the next year in September, in response to the day length, day-neutrals make flower buds all season, giving the potential for, as the photos show, ripe strawberries on Oct. 25 and well beyond.
Of the day neutral varieties available, Schultz planted Seascape. “It has the best flavor of the day neutrals,” he explained. “Other varieties may be bigger and more productive, but at Linvilla, our customers are looking for flavor. Customers actually ask for Seascape by name.”
Interestingly, the berries picked from this June-planted field-now, in late October — are bigger than the berries picked last summer.
“Here in southeastern Pennsylvania, we can have temperatures in the 90s in June, and the berries are smaller, because the plants are stressed by the heat.” But by Oct. 25, frost is always a possibility. When frost is anticipated, the row cover folded in the middle of the strawberry field is easily and quickly unfolded to cover the whole field, and is held in place by used helicopter rope. “Helicopter companies sell the rope after it’s been used awhile. Four men can pull 400 ft. of rope with no trouble, and we don’t need to bother with sand bags or cinder blocks to secure the edges of the row cover.”
Under the row covers, the strawberries themselves can take temperature as low as 20 degrees in stride without sprinkling, but “flowers and buds are very sensitive,” Schultz explained. “If the row cover touches a flower on a cold night, that flower is done. That’s why we started using hoops on the rows, to hold the row cover up in the air and off the plants.”
Part of the field being picked, as part of the experiment, was not covered by the row cover. Schultz showed signs of the previous night’s frost damage to the strawberry flowers. The slight browning looked mild, “but tomorrow they’ll be completely black,” he added.
“The first year of the grant, we picked day-neutral strawberries until Thanksgiving. This year, with our new staggered planting method, we expect to go at least to Thanksgiving, and maybe pick until Christmas.” By November, however, plants are picked only once a week.
For adequate cold-protection for this time of year, don’t skimp on row cover quality. Schultz uses a row cover weighing 1.25 ounces per square yard. “That’s triple the weight of the covers most growers routinely use, and costs about 30 percent more, but you need that amount of protection.”
The new planting method involves staggered plantings, with fields planted April 1, May 1, June 1 and July 1. “The field planted July 1 is the most productive in October and November,” said Schultz, “because it has not had the burden of producing fruit in July and August.”
When winter temperatures get too low for continued strawberry production, workers at Linvilla weed the field one last time, then mulch the plants heavily with straw for the winter, using a round bale buster. The next spring, the straw is pulled back, and “the plants are treated like June-bearing strawberries.”
Prices for the Seascapes at Linvilla are good. Sold at the market, they sell for $3.99 a pint, or $6.99 a quart. For their popular PYO, day-neutral strawberries sell for $3.99 a pound, and sell wholesale for between $2.66 and $3.33 a pound.
“We plant 14,000 plants per acre, and get .4 to .7 pounds of marketable fruit per plant,” he explained. “For the grant,” he continued, “we also took some flats of strawberries to the auction, to see what prices they would bring. While June-bearing strawberries sold for $25 a flat in the summer, at the auction in the fall we get $30 for 12 pints, or $32 for 8 quarts per flat.”
Disease problems appear to be minimal. “Seascapes aren’t affected by leaf spot, red stele, or phytophthera as readily as some varieties, as long as you’re maintaining them,” explained Schultz, and they have no problems with overwintering. For Botrytis, “there are lots of good fungicides available. We spray when the flowers open, then don’t have to spray during picking.”
Insects are more of a problem. “We sprayed often this summer for the spotted wing drosophila, and sap beetles are a regional problem for us.”
An additional potential problem, especially in heavier soils, is cultural: planting the bare-root plants too deeply. Schultz has noticed that there are stunted plants about every four to six plants in their June 1-planted field. “They never make fruit. These stunted plants were our biggest source of yield loss.” Schultz has concluded that with Linvilla’s heavier soils, the problem is planting too deeply. “This was never a problem in New England’s mostly silt soils, where we could push the plants in deep. But in the heavier soils here, planting too deeply seems to result in stunting.”
Part of the requirement for the grant is that Schultz freely shares the information that he learns. To that end, Linvilla recently held a field day. “A lot of growers, particularly in Virginia and Delaware, are interested in doing more with day-neutrals, and are trying to work the kinks out,” commented Schultz. I’ve been out of school since 1987. I would love to say that a part of my career was spent developing some new techniques to help increase yields and profitability and reduce problems in growing a currently under-utilized crop like day-neutral strawberries.
“I couldn’t do this, however, without the help of the PDA and the support of the Linvill family.”
Linvilla Orchards experiments with day-neutral strawberries
by Bill and Mary Weaver