At Mertz Greenhouses, in Northumberland, Penn., where workers can pick 20,000 pounds of tomatoes a week at the height of the season, close attention is paid to small details.
“We take weekly soil samples,” said Mike McPherson, general manager of the family-owned business, rotating from house to house, so that all houses are sampled every five weeks.
“But if we get a house where the plants don’t look quite right - too dark or too light or spindly, for example - we’ll sample that house right away. And every three to four weeks we send leaf samples away for analysis.”
Bumblebees pollinate the tomatoes, so no insecticides can be used, and the operation depends on regular releases of predator insects and on Botaniguard 22 wettable powder, which contains spores that can kill problem insects.
“We use the wettable powder formulation,” explained Mc Pherson. “There is also a liquid formulation, but it tends to burn the plants.”
A Pennsylvania Department of Agriculture employee, Cathy Thomas, makes regular stops to scout for insect problems, and sometimes she also takes care of ordering the predators needed.
“Predators keep the insects controllable, although they don’t get rid of them,” commented McPherson. “The predators are working seven days a week. Costs of using predators are pretty competitive with spraying insecticides. It takes a lot of man hours to spray this whole complex.”
Fungicide sprays are seldom needed because workers prune regularly, are careful to keep bottom leaves removed, keep a close watch on the ventilation, and never let the temperature get below 64 degrees.
The pollinating bumblebees, purchased from Biobest in Canada, live in a small rectangular plastic and cardboard box in each greenhouse, and, once released, pretty much take care of themselves. Biobest ships three sizes of colonies, depending on the number of square feet in the greenhouse, and how pollination is needed. Each colony contains a queen, female worker bees, and eggs and developing larvae.
When the carton arrives from UPS, McPherson opens the sugar-water bottle tank inside, which supplies food for the adult bumblebees. In the wild, they would collect nectar for food, but, according to Frank Marchetti of Biobest, tomato flowers produce no nectar, so the sugar-water syrup must be supplied. The worker bumblebees pollinate the tomato flowers in the process of jostling them while collecting pollen to be fed to the developing larvae.
In the wild, a bumblebee colony lasts as long as its food source lasts. In the greenhouse, colony life is normally shorter. The greenhouse environment isn’t the best for bumblebees, Marchetti related. There is insufficient shade, sometimes it can get too hot, and tomato pollen is not as good a food source for the larvae as many other pollens.
“Twelve weeks is about the average life of a quality bumblebee colony in the greenhouse,” said Marchetti. “We put out our colonies once a season,” added McPherson. “They kind of peter out toward the end, but by then, the plants are up to the wires, and we can go around and tap the wires to jostle, and thereby pollinate, the flowers. We have time to do that then. The flowers also get jostled when we hand prune once a week.”
For the spring/summer harvested tomato crop, plantings are made in three stages, one in December, one in January, and one in February, to avoid having all the plants at peak bearing at the same time. All plants are of the greenhouse tomato variety Trust. Plants are picked for about l4 weeks, and each plant produces six or more clusters of tomatoes.
“We want to bail out once the local farm and garden tomatoes come in mid-August,” explained McPherson, “so we top the plants in the beginning of July, right above the last cluster. Then the plants put all their energy into developing the fruit. They’ll fruit for another six weeks, but no new flower buds will be formed.”
A second tomato crop is planted in the fall, so when frost hits and everybody else loses their tomatoes, the greenhouses can be back in business. Picking on that crop stops at Christmas.
After each crop, the soil, (a peat moss, vermiculite, perlite blend), and the troughs are covered with plastic tarps and steam heated to 200&Mac251; to sterilize them. Then the soil can be reused.
Also, at the end of the summer picking season, the houses are tightly closed and are allowed to heat up to l50-l60 degrees for eight to ten days to kill all the insects, larvae, and eggs before the next planting. “The heat wipes them out,” said McPherson. “It can also wipe out the PVC pipes. We have to take them out. The heat cooks the glue, and if there’s any water pressure, it blows the pipes apart.”
Once the tomatoes start bearing, they are picked on Monday, Wednesday, and Friday. Only fruit starting to turn pink are picked. Everything is graded into four grades by hand on a long table, and is packed by hand, by a five- or six-person crew, with three people grading, two weighing, and one or two workers making boxes. “Everybody I have here can grade,” said McPherson. “We switch jobs around. You can get bored doing the same thing all the time.
“If someone orders, say, 500 pounds,” he continued, “we give them three ripenesses. Then when they need the least ripe, they can set them in the sun to finish ripening.” Boxed tomatoes are held at 60 degrees. “You want to hold them, not cold them,” he added.
For labor, McPherson is fortunate to have a very experienced crew. He purchased the business just a year and a half ago from Boyd Mertz, who had operated the greenhouses successfully for the past 40 years.
“Boyd calls himself a subcontractor now,” he related, “but he is in here every day. His right-hand man, with 33 years’ experience, also stayed, along with Boyd’s cousin, who has been here for 3l years. You couldn’t buy the knowledge they have. They really know what they’re doing, and I’m not afraid to listen. I learned the business from Boyd. I started picking tomatoes here when I was 12.”
Tomatoes are sold mainly to farm markets and small “mom and pop” grocery stores in Pennsylvania and New Jersey. The operation runs a New Jersey route twice a week with l3 stops on it, and during parts of the season, runs another route into western Pennsylvania. A lot of local businesses simply phone in orders and pick up their tomatoes at the greenhouse. Prices are the same for pick-up or delivery.
Delivery schedules get particularly hectic around Mother’s Day and Memorial Day, when the operation is also selling bedding plants and hanging baskets. McPherson makes a point of giving good service. “If markets run out, we’ll deliver Saturday and Sunday if we have to. I do most of the weekend deliveries myself. We can’t let our markets run out and be left hanging. We will take care of them.”
“We’re always looking for more markets,” he continued. “We picked up a couple this year. We have no problem with the growing. With the experience of the people here, we could grow anything. The question is, can we sell it?”
About half the greenhouse space is in tomatoes, and the other half is in bedding plants and hanging baskets, sold to many of the same customers who buy the tomatoes and some garden centers. Hanging baskets are also in the tomato houses, but only in the aisles, never over the plants, which would invite disease problems.
“We grow a big basket,” related McPherson. “We figure bigger is better, and we don’t have any trouble selling them. A basket retails for $l5 to $25. Last year we sold out the l4th of May. This year we sold out the 24th of May. I don’t contract anything.
“My farm markets want quality, and quality is what sells,” he continued. “We can’t compete with the big operations on price. If we didn’t have quality, we’d be out of business.”
In bedding plants, the operation is finding that larger plants in 4 l/2 inch pots sell well. “The world is getting so fast-paced. People want bigger plants for instant color. The price just doesn’t seem to matter. It’s instant color, already done, see you later, I’m busy. You have to change with the times or be left out in the cold,” he said.
For the future, McPherson is considering switching another of the tomato greenhouses to flowers, maybe for 4 l/2 inch New Guineas and ivy cuttings.
