Story last updated at 6/27/2012 - 2:07 pm
Gardening season is well underway in Southeast Alaska with early radishes, lettuce and other greens already finding their way to our dinner plates. The potatoes, peas, carrots, onions and beets have cautiously emerged from the earth and are gaining in size slowly but surely. Plants started indoors under lights may be safely transplanted outside or into the greenhouse to brave the elements.
Here on Prince of Wales Island, we may be well past the last chilling frost but the constant rain and moderate temperatures remain a challenge to vigorous growth for tender transplants. Sure, we're getting a lot of daylight but where's the heat? Most days have hovered around 50 degrees Fahrenheit for daytime highs and even overcast days without precipitation can't compare to blazing sunlight for plant production. The good news is that temperatures may be higher as summer progresses.
This is not to say that gardening cannot be fruitful in Southeast Alaska. Just like everywhere else, certain plants thrive in this particular climate but many of our favorite vegetables need extra heat to bear fruit and ripen. A greenhouse, even a simple PVC hoophouse with greenhouse film like the one I built ten years ago, can make a significant difference in air temperature. In mid-June the temperature outside is around 55 degrees, while the thermometer in my greenhouse reads nearly 80.
According to Rodale's Garden Problem Solver by Jeff Ball, zucchini, if it had its druthers, would prefer an air temperature of 70-85 degrees while bush beans can live within 60-80 degrees. Even the cabbage and broccoli fancy at least 60 degree weather in the daytime to really prosper. Unless it's an unusual summer, like 2009 when blue, sunny skies prevailed, I've had better success growing cabbage and broccoli in the greenhouse than outside. Greenhouse growing is more time consuming since now all the watering must be done by me but at least it keeps the continuous onslaught of rain from overwatering and provides a safe haven from the many rapacious deer that live in Thorne Bay.
A higher air temperature is attained in my solarium, which is accessed through a sliding glass door from my living room. It is essentially a closed-in porch covered by clear roofing and greenhouse film with supplemental heat available from the wood stove in the living room. This year I've added one inch of rigid foam board on the floor and another layer of greenhouse film on the inside of the framing, creating an air pocket for a noticeable increase in heat retention. On the occasional sunny days, the hot solarium helps heat the house.
In the solarium, the tomato plants I started in the house under lights in early February are plugging along with lots of green tomatoes on 4- to 6-foot plants. One must be very patient when gardening in Southeast Alaska and remember to appreciate that at least we don't have to suffer from really hot weather like many locations where tomatoes easily grow right outside. The solarium also houses cucumbers, peppers, experimental container-grown celery and corn, and about a dozen hanging baskets of flowers that I really don't have room for.
This year, in a perfect example of how a little more heat can improve growth, I was able to compare the vigor of some plants grown both in the greenhouse and solarium. Apparently even cabbage appreciates a little more warmth. After transplanting all the cabbage and broccoli I could fit into the greenhouse (and actually spacing them sensibly) I put the remaining plants in containers in the solarium. After a month, the pampered container plants were considerably larger than the ones in the greenhouse.
Things are tougher out in the greenhouse where temperatures are lower, humidity higher and all manner of slugs and bugs try to gain a foothold. As temperatures improve, the greenhouse plants are starting to catch up so it will be interesting to compare the final products, especially since I haven't tried cabbage and broccoli in containers previously.
Summer gardening fun is upon us with all those potential hours for nurturing, cultivating and admiring, breathing in the tantalizing aromas, cursing of slugs, digging in the dirt and hopefully even harvesting some flavorful produce.