PLANT CITY — It's that time of year again.The plastic is down.Strawberry farmers have spent two weeks prepping the soil and then sealing off the strawberry mounds with sheets of black plastic to lock in nutrients and antifungal chemicals.Within the next week, most of the plants across 10,000 acres in Hillsborough County will be in the ground. By Thanksgiving, the first batch of strawberries will be ripe for the picking.Strawberry farming is year-round work, said Ted Campbell, executive director of the Florida Strawberry Growers Association. It has an economic impact on Hillsborough of about $1 billion, he said. The plants are grown in Canada and then shipped to Florida for planting. "They're just like all the other snowbirds that come down here for winter," Campbell said.Once they are in the ground, farmers will water them in the afternoons to keep them cool. The plants take about 10 days to take root and then are nurtured until they start to yield fruit.The harvesting season stretches from the end of November until the end of April."It's not a sprint, it's a marathon," said Andy McDonald, operations manager at Sweet Life Farms in Plant City.It's still a bit too early to tell what kind of year this will be for strawberries."Every year is different. That's the first thing you learn around here," Campbell said.All the rain this year has made it harder for the farmers to seal off the ground and nutrients before planting, Campbell said.But rain, of course, is also a blessing. The strawberry plants need plenty of water as they take root, Campbell said."It's a good thing, but it's really making the soil preparation a little more challenging," he said.McDonald said he was able to treat and seal his fields — about 135 acres — without any problems. He'll start planting this week.His greatest challenge now is finding the labor to help him in the fields. Because of new immigration laws in Georgia and Alabama, McDonald said he and other farmers are having trouble hiring the migrant workers they usually employ during strawberry season. He has 70 on his payroll, which is fine for the time being, but he'll need about 200 in March and April, the height of picking season.He knows other farmers who had trouble finding enough help to treat the soil and put the plants in the ground."I'm in pretty good shape compared to other farmers right now," McDonald said.And the farmers aren't forgetting the unpredictable Florida weather in their season forecasts, McDonald said.The past two winters have been unseasonably hot.Warm weather last year produced a surplus of berries, which were cheap and not as good as they usually are, McDonald said.That made it harder to keep up with Florida strawberries' newest rival: Mexico. "We had so much bad weather, we couldn't compete with them last year," McDonald said.The only way Florida growers can compete is to produce superior strawberries, price them competitively and encourage people to "buy American," Campbell said. Strawberry packages are always marked with the country of origin."The American farmer needs the help of American consumers," he said.McDonald agreed."And it's going to be tough to compete with Mexico, because they're just going to get better and better," he said. "But all we can do is work hard and market better."Despite the challenges the year may or may not bring, growers are still looking toward the coming months with a glass-half-full perspective."We're looking forward to a good year," McDonald said.