SNEAK PREVIEW: Growing Green

Old timers in Fairbanks say that the first week of June is the safe time to put in outdoor plants, but Plant Kingdom founder Cyndie Warbelow says customers are asking for plants earlier. In recent years, the busiest weekend of the year has often been Mother’s Day weekend, a day that’s big in the nursery industry in the Lower 48 but was previously considered too early for Alaska’s Interior.

This year—which saw a particularly warm spring—customers started coming in two months before the start of the traditional gardening season, says current business owner Stephanie Bluekens, who purchased the business from Warbelow a few years ago. But even though climate change has generally made planting early a safer bet, it still has its risks.

Last year, for example, there was frost in the second week of June. Greenhouse operators can protect their plants from frost by bringing them indoors, but it comes at a cost. The business model is based on rotating plants through the greenhouse quickly.

“Things keep growing so you’ve got to be able to move stuff into your own outdoors and into your customers’ yards,” Warbelow says. “Things keep taking up more space, so the sequence needs to keep working in the right direction.”

Even with the chance of a late frost, Warbelow says the risks of starting early are worth it to be ready with plants when customers want them.

“I’ve seen killing frost for at least squash every month of the year. Agriculture is a form of gambling, and it pays to gamble,” she says.

“This year it was warming up gradually and I felt you’d be wasting the spring if you didn’t plant. I planted my garden the third week in April.”

Greenhouses work by bringing solar light and heat in through transparent ceilings and walls and trapping the warm air inside.

In other climates, solar heat alone is sometimes enough to grow plants that otherwise couldn’t be grown outside. But sunlight alone isn’t enough to warm a greenhouse to growing temperatures when it’s -20˚F outside. To operate in winter, Alaskan greenhouse owners often add supplemental heat sources and may insulate the greenhouses to prevent heat loss.

At Plant Kingdom, each greenhouse has two oil-fired furnaces: one to be used as a backup if the first one fails.

The first greenhouse the company starts up each year doesn’t look like a greenhouse; it’s a blocky, opaque half-building connected to a conventional-looking greenhouse. The business uses this insulated greenhouse for starts because in February transparent walls would cause major heat loss without bringing in much light.

The other greenhouses at Plant Kingdom are a mix of the traditional gable-roofed design and rounded Quonset-hut-shaped buildings. The Quonset design is especially good for letting in light but can more easily get too hot, Bluekens says. She also worries about strong wind ripping through the polyethylene plastic film walls of the Quonset-style greenhouses.

Elsewhere in Alaska, gardeners warm greenhouses using heat sources other than sunlight, including wood and natural gas. For farmers lucky enough to have access to it, geothermal energy is a powerful greenhouse heater. Hot springs allow for a winter plant oasis in several parts of Alaska, including Pilgrim Hot Springs near Nome and both Manley Hot Springs and Chena Hot Springs near Fairbanks.

Having access to hot springs allows growers to produce fresh vegetables outside their usual range and outside the usual growing season.

Read the full article in the August issue of Alaska Business.