A Glimpse of Green in the Heart of Winter

Given the climate of the Northeast, our world remains fairly green even during winter dormancy. Lawns stay almost green, pachysandra beds form seemingly endless drifts of bright emerald green, and even our wonderful winter woodlands are dappled in dull green by hemlocks, pines, mountain laurels, and moss covered rocks. But it’s the vibrant green of new growth bursting forth that is seldom seen this time of year, and why it's so common for gardeners to pass the winter months drooling over seed catalogs, choosing varieties, and sketching elaborate garden plans. Less common, and perhaps underappreciated, is the wonderful winter tradition of germination tests!

cosmos cotyledons

Every winter, my seed collection, usually stored in the basement in assorted boxes, tubs, and bins, migrates upstairs and takes over my kitchen counter, sometimes sprawling onto the kitchen table and even into other rooms. Part of my ritual of ordering seeds involves first going through the large and random assortment of seeds I already have, including seeds I’ve saved, extra seeds leftover from previous seasons, seeds that have been given to me, and seeds I bought but never found the time or space to grow. And, of course, I have all different types: vegetable seeds, herb seeds, flower seeds, perennial seeds, seeds collected from local native plants. Some are from last year, and some I’ve been holding onto for more than a decade. With a few exceptions, such as onions, I expect most of these seeds to remain viable for at least five years. But before I reserve prime garden space for them, I like to do a quick germination check and make sure they still have a decent germination rate and good vigor. And even though I know it will be months before I’ll get out into the garden, it’s still fun and inspiring to have bright seedlings on the counter for a week or so while I work up my fantastical seed order for next year.

Often overlooked, so many of the natural processes we witness on a regular basis are, quite literally, awesome. And there’s almost no natural process to watch that’s more inspiring than germination. Genetically programmed to stay in a resting state until conditions for growth are favorable, many seeds only require moisture and the right temperature, and within a few days, the seed’s potential unfurls as roots and shoots burst forth and leaves begin to develop—leaves that will soon begin to photosynthesize, another process which is not visible to the naked eye, but is equally as amazing.

For most home gardeners, the hardest thing about starting seeds inside is providing them with enough light. But to do a germination test, the seeds just need to sprout and grow for a few days, so it doesn’t matter if they get leggy or spindly. There are two simple ways to do a germination test at home. Seeds can be planted into potting mix, just as if you were starting seeds for the garden, or seeds can be germinated on or in moist paper towels. Potting-mix tests are a little easier to set up, but they take up more space. Paper towel tests—I use square, unbleached coffee filters—require a little more patience to set up. But at the end, it's pretty fun to see the entire seedling, roots and all. You can also do a quick visual scan and assess the rate of good, viable seeds to non-germinating seeds. If you test the seeds in potting mix, you only the see the sprouts from the healthy seeds, and you've got to count seedlings and do some math to figure the germination rate. But regardless of method, I find it’s pretty easy to get an appropriate combination of temperature and moisture by placing the seeds in a covered container on a heat mat on my kitchen counter. It's certainly not even close to optimal conditions, but it serves its purpose.

Cosmos germinating 1
Cosmos germinating 2
Cosmos germinating 3

Four quick tips for running germination tests at home

  1. Count exactly the number of seeds used. When the seeds have germinated, you can calculate a germination by dividing the number of seeds that germinated by the total number of seeds used in the test. To make this a percentage, multiply the result by 100.
  2. Make sure to give each seed enough space to germinate. You'll realize the importance of this when trying to count seedlings.
  3. Consider how long a species normally takes to germinate. Some species need just a few days for germination to start; these are ideal for counter-top germination tests. Some take weeks or longer; these are only ideal for counter-top germination tests conducted by very patient gardeners!
  4. Many native plant seeds have some form of dormancy. This prevents seeds from germinating — even under ideal conditions — until the seeds undergo other specific physical, environmental, or chemical processes that break dormancy. Most of our vegetable garden species lost their dormancy mechanisms during the process of plant domestication, so you should be able to simply set up the seeds and go!