by Scott Canning, Director of Horticulture and Special Projects
SOME THOUGHTS AND TIPS ON SEED STARTING
When reflecting on my more than 30 years of professional gardening, I think learning plant propagation is among my most exciting adventures. Let’s face it, what gardener doesn’t want more plants? And when it comes to plant propagation, seeds are both fascinating and prolific. Late winter means SEEDS! Growing from seed has some distinct advantages over other means of propagation: A packet of seeds can hold dozens to thousands of potential plants. Compare that to lifting and dividing an established clump of a perennial plant, taking cuttings, or learning the carpentry involved in grafting. And you probably already have a mailbox full of seed catalogs, or websites bookmarked on your computer. Going online is becoming the gold standard, because of the paper and carbon emissions saved—and you save time, because your order can turn around faster. Confused where to start? Here are some tips.
Where should you shop for seeds? I found this website aligned with my beliefs and my favorites. To this I would add John Scheepers Kitchen Garden Seeds, a more conventional favorite of mine. And don’t forget about seed lists available from myriad garden societies: I am a member of the North American Rock Garden Society to shop its exquisite annual seed offerings. I also loved the J. L. Hudson Seedsman catalog because it was a manifesto, but it has gone to an online format still worth visiting. I know some readers will be incensed because I didn’t mention their favorite seed source, but hey…
Once you have selected some seeds, what’s next? Growing plants from seed at home was especially frustrating for me, until I started to grow under artificial lights in a controlled environment. My seedlings either baked on my hot dry windowsill, or turned pale, stretched, and died from lack of sufficient light. There are many options for plant lighting systems out there, but I am starting seeds, not growing marijuana or another cash crop. I chose a T5 fluorescent light fixture with four 4-foot bulbs. It is a small capital expenditure, gives me more than enough well-lit space (more than 12 square feet) to start all my seeds, and stores easily the rest of the year. You can start with a fixture as small as two tubes that are just two feet long, but I’ll bet you will out-grow it. The cost of highly-efficient LED systems is coming down, but at this time they make more economical sense for year-round growing, and I’m talking about approximately 12 weeks of seed starting. T5 bulbs are efficient, inexpensive and stay quite cool. I choose High Output (HO) T5 bulbs for added efficiency and a better spectrum for seedlings.
Growing seeds under humidity domes also transformed my experience, but most were either too short, or made of cheap plastic and flimsy. I now grow in trays fitted with ventilated, clear acrylic domes that are tall and will last for years. I use the “XL High Dome Propagator” from the Greenhouse Megastore found here. They are nearly 16” wide by 23” long and almost 9” tall, so my seedlings no longer press against a wet, cheap plastic dome, inviting disease—unless I am negligent transplanting my seedlings in due time. I start most of my seeds in 3-inch pots full of a sterile seed-starting mix to avoid disease, and I can fit a bunch of them inside this propagator. I have multiple propagators, because I sow seeds that resent being transplanted in individual-sized pots for planting out after frost, and that takes extra room.
The nuance involved in growing plants from seed is way beyond the scope of this short piece. With “conventional” seeds (meaning easy annuals and most vegetable garden seeds), the main concern is the depth of planting, whether or not to exclude light until the seed germinates, and the proper time to sow the seed. If you wish to explore the universe beyond “conventional” seeds you need to discover the world of seed dormancy, and how it is overcome. I greatly admire the huge amount of work that Margaret Roach shares on her incredible blog, A Way to Garden. I don’t believe in re-inventing the wheel, and Margaret should win an award for assembling so much info on seed-starting in one place. She even has a seed calculator where you can plug in your zip code to get the recommended sowing date for either direct-sowing in the garden or starting the recommended number of weeks before your expected last frost date for starting seed indoors. How cool is that? I encourage you to explore along with her, and once you have the right, basic equipment and a season of seed-starting under your belt, I dare you not to get hooked. Your life and your garden will be much improved by this exciting adventure.