For many gardeners in the lower 48, the sky is the limit for varieties they may plant in their gardens. For those of us gardening in the sub-arctic, we’re not so lucky. Unless, of course, you have a greenhouse or indoor garden where you can control the climate.
In Fairbanks, we have two issues that affect our gardens. First, and probably most obvious, are the relatively cool temperatures that we see. In the heights of summer, we’re lucky to push lower 90’s during the day and it’s common to see evenings dip below 60 degrees Fahrenheit. The evening dips can impact many warm weather plants, such as tomatoes and peppers, where fruiting may not take place with certain varieties when lows dip below 60 degrees.
The other issue, also obvious, is our sunlight. The land of the midnight sun obviously offers a huge amount of sunlight during the summer, with 22+ hours of light blasting our plants. The problem here is not necessarily the light, but actually the lack of darkness. Many plants have hormonal responses, based on the amount light/dark received, that help the plant decide when it’s time to go to seed. Our atypical summer sun easily confuses many varieties and can cause early maturation, forcing plants to go to seed early. The problem is these plants think fall is right around the corner, when in fact our growing season is barely getting started.
For these reasons, it’s often highly beneficial for us northern gardeners to seek out specific genetics that will do well with both these factors. Most cool weather crops will do extremely well here, with a couple of exceptions. For things like beets, spinach and radishes, a variety used to our summer sun will definitely help combat early bolting. That said, at least with radishes and spinach, our growing season is early and late with little exception. There are limits to when you can grow these things. It should also be noted, that for things like broccoli, you have perhaps a window of 2-3 days between a good harvest and early seeding, so keep a close eye on those plants as they mature!
For almost all warm weather plants, like tomatoes, peppers and cucumbers, you will be best served by seeking out varieties bred for our conditions. Put simply, outdoor growing of these plants will present challenges to even the most experienced northern gardener. No matter what you do, you’re probably going to pick a healthy number of green tomatoes right before first frost. Peppers will likely produce low yields and with tomatoes, you will likely have to harvest early before first frost.
With warm climate vegetables in particular, the challenge of overnight low temperatures is a big one here in Alaska. Many tomatoes and peppers will simply refuse to fruit if the low temperatures dip below 60 degrees at night. There’s nothing more disappointing than growing a plant to near fruition, only to have it produce nothing. For these varieties, source your starts locally or use seed stock for varieties that will fare well in our cool climate.
Of course, there’s a few things you can do to help with some of the natural challenges northern gardeners face. For the problematic cool weather crops, seeking out a growing site that shields plants from sunlight for some of the day will help. Ideally, trying to get 10-12 hours of sunlight will help you get a few more weeks of harvest out of these plants. For warm weather crops, using hoop houses, green houses or indoor gardening techniques will be the best solution to grow any variety successfully. Another tip would be to diversify your garden with multiple varieties, which can help if one variety doesn’t do particularly well in a season.
Exploration of this topic would be less than helpful without pointing out specific resources. Fortunately, the University of Alaska Fairbanks puts together a recommended variety list. Additionally, our local nurseries are producing starts with varieties that will do well here in the interior of Alaska, so you can’t really go wrong buying local starts. You can find our favorite seed suppliers here in our resources section.
One last tip. Gardening is about exploration and learning and there’s nothing wrong with a bit of experimentation. Feel free to try new varieties and types of plants, with a bit of research on the variety or plant, you can quickly find more varieties that will do well here outside of the above lists. For example, last year we tried out ground cherries and had immense success in both yield and quality, but you won’t find these on any lists! So it pays off to try new things, but be sure not put all your eggs in one basket.