Califonia Bountiful

Seeds of success

September/October 2017 California Bountiful magazine

Transplant process helps bring fruits and vegetables from farm to fork

Many crops in California, including tomatoes, celery, cauliflower and watermelons, start as seeds in a greenhouse and are then transplanted to farm fields. Greenhouse photo: © 2017 Richard Green

When we imagine where our food comes from, we may conjure up images of a farmer sowing handfuls of seed into plowed fields. But for many crops, modern techniques have made planting seeds directly into the ground virtually a thing of the past.

Seeds today are often sprouted in greenhouses, where they are nurtured into small plants and then transplanted into fields. "Farm to fork" tells only part of the story of our food's journey; sometimes "transplants to taste buds" offers a more complete picture.

Transplanting greenhouse-grown seedlings offers a number of benefits, said Timothy Hartz, extension specialist in the Department of Plant Sciences at the University of California, Davis. Extending the growing season is chief among them.

Starting seeds in a greenhouse offers climate control, allowing farmers to outsmart fickle early-season weather. This jump-start on the season allows plants to sprout weeks before they would in the ground. For shoppers, that means the long winter's wait for seasonal items such as sun-grown tomatoes can be over that much earlier. For some crops, harvest can begin as many as three or four weeks sooner.

And, because farmers can plant multiple waves of crops a year using transplants, starting the next batch of plants in a greenhouse while the first is still in the ground can stretch harvest later into the season as well.

Though a modern technique, transplanting isn't exactly a new one.

"Bare-root transplants have been used for many decades," Hartz said, and growing transplants in container trays in greenhouses dates at least to the 1960s.

Today, almost all the tomatoes, watermelons, celery and cauliflower in California are grown this way, Hartz said. Transplants are also used to grow peppers, lettuce, broccoli, cantaloupe, Brussels sprouts, cucumber, eggplant, kale, onions and more.

Speedling is a Central Coast company that grows seedlings, such as the tomatoes, top left, for farmers to transplant in their fields. Seeds are planted in trays using a dibbler drum, top right. To irrigate, trays are floated in water, above. Photos: © 2017 Richard Green

Bringing up baby (vegetables)

Often, the transplanting process involves a partnership between farmers and greenhouse growers. Much like a set of parents, it takes two to bring vegetables into the world and raise them to ripeness under the California sun.

Speedling is a Central Coast company that has been growing transplants for farmers nationwide for nearly 50 years. It takes seed, supplied by the farmer, and nurtures it into a young plant that will survive on its own in the farmer's field.

"We are essentially a nursery service," explained Hector Huizar, West Coast operations manager for Speedling. "A seedling is most vulnerable in its youngest state, in the first 60 days. We reduce risk involved when the plant is most sensitive."

Peek into any one of Speedling's greenhouses—they have five in Central California and more in Florida, Georgia and Texas—and you'll be greeted with a sea of green. More than 600 million young vegetable plants are grown annually in their West Coast facilities alone.

Growing seeds in a nursery allows for the specialized attention and techniques that ensure the seed will indeed germinate, or sprout. The service proves essential to many farmers, who can avoid wasting seed and maximize the use of their land and other resources, such as water and fertilizer.

"If you have a 100-acre farm and you throw celery seed out into your field, 80 percent of that may germinate, so now you have 20 percent of your farm that's not planted," Huizar explained.

Growing with transplants also reduces other threats such as extreme weather or birds and insects eating the young plants. Plus, modern greenhouse technology and techniques can help use fertilizer and water efficiently.

At Speedling, seeds are planted in trays featuring an inverted-pyramid design. Each seed is planted into a small amount of growing media, such as peat moss. To irrigate, the trays are floated in water. Sometimes as many as 900 trays are irrigated at once, and because the trays are made of light Styrofoam, they can be easily moved with the push of a paddle.

"This allows you to water a lot of plants at once with less water, and keeps the foliage dry, which mitigates disease or pest issues, as most plant diseases are spread by wet foliage," Huizar said.

DiMare Co. employees prepare tomato seedlings, left, which are transplanted three rows at a time. Photos: © 2017 Richard Green

A perfect pairing

Still, transplanting isn't routinely used for every crop. Crops with high costs for seed are the likeliest candidates, as the advantage of guaranteeing the seeds sprout outweighs the additional expense of greenhouse growing. Tomatoes are one crop where the benefits of using transplants generally pencil out, and Speedling grows plenty of them. As the largest grower of processing tomatoes in the country, chances are one of Speedling's California greenhouses is the point of origin for that squirt of ketchup accompanying your fries or the sauce on your pizza.

Speedling also grows fresh-market tomato transplants. The DiMare Co., based in Newman, near Modesto, uses Speedling transplants to grow fresh, round, Roma and yellow tomatoes throughout California. The farm's tomatoes eventually go to restaurants and grocery stores across California and the nation. DiMare has been growing with transplants for decades—and for good reason.

"You are taking each individual seed and giving it the best care, so you are utilizing your seed more efficiently," said Jeff Dolan, field operations manager for The DiMare Co.

In mid-March, the DiMare fields near Los Banos are primed and ready for tomato transplants, which will grow into mature plants. Just as for any pair of doting parents, constant communication between Speedling and DiMare growers has helped them reach this point.

"I'm out meeting farmers in their fields, seeing how things went last year, looking at production, measuring acreage," Huizar said.

And although DiMare growers entrust Speedling with the responsibility of babying their seeds, they continue to monitor the seeds' progress into seedling.

"I travel to their facilities once a week to every other week," Dolan said. "I'm constantly in contact with Speedling. I'm looking at our inventory. I don't want to over-seed or under-seed."

Dolan noted that the seeds get specialized attention while under Speedling's care. The results of the process speak for themselves.

"In the 1980s, we stopped any direct seeding in our fields. From that point on, we have been 100 percent transplants," he said. "Our yield has gone up tremendously—from several hundred cartons an acre to now well over 1,000 cartons an acre on average."

The impressive efficiency of California tomato growers—aided by the practice of transplanting—is one factor that allows them to supply families across the entire nation with fresh tomatoes and tomato products.

One partnership, millions of little sprouts and a bumper crop of delicious: just another California transplant-to-taste-buds tale.

Jennifer Harrison and Shannon Springmeyer

The life of a tomato

From tiny sprout to ripe fruit, many hands work to nurture tomatoes. Here's a look at how transplant-grown fresh tomatoes make it from seed to your plate.

Photo: Shutterstock

  1. Farmers provide seeds to the transplant nursery.
  2. The nursery plants seeds in special multi-celled trays with a small amount of sterile planting mix and one seed in each cell. 
  3. Seeds are watered and fertilized in climate-controlled greenhouses until they sprout. Seeds can sprout weeks before they would outdoors, growing even in the middle of winter.
  4. Seedlings are cared for and monitored for pests and disease for 48 to 60 days, as they grow into bigger and stronger plants.
  5. When the young plants are 8 inches tall, they're ready to be transplanted to open fields.
  6. Workers on the farm hand-load each seedling, one by one, into special planting equipment that plants the young tomatoes in evenly spaced rows.
  7. Farmers tend the tomatoes carefully into mature plants. Because the young plants are already strong and healthy, farmers can use their water and fertilizer efficiently.
  8. After 82 to 115 days under the California sun, ripe tomatoes are ready for harvest. Each tomato is delicately hand-picked. 
  9. Tomatoes then head immediately to the packing shed for washing, sorting and sizing. Electronic "eyes" scan for sunburn patches that humans can't see, ensuring no damaged tomatoes are shipped.
  10. From coast to coast, grocery stores and restaurants await the arrival of freshly picked, California sun-grown tomatoes. 
  11. Atop burgers, diced into salads, tossed with pasta—tomatoes are ready to enjoy.

Sources: The DiMare Co. and University of California Agriculture and Natural Resources

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