Everything we do here on the farm is in some way a learning experience. No two seasons are the same. And if we mess up, we have to wait patiently a whole year before we can put our newfound knowledge to good use. Some call it trial and error. I call it learning the hard way.
This was the winter that never came; our seasons are becoming so unpredictable. Our plant hardiness zone shifted a full degree on the updated USDA map, which I could feel without looking at a map. Spring this year rolled in like a lamb. Bathed in sunshine, the tulips we planted in front of the house popped up in late February. The birds began singing again, the peepers returned to the pond behind the barn.
Slave to a springtime passion for the earth.
Robert Frost
How Love burns through the Putting in the Seed
On through the watching for that early birth
When, just as the soil tarnishes with weed,
The sturdy seedling with arched body comes
Shouldering its way and shedding the earth crumbs.
It felt perfectly in line to start seeds the very first day of March. I start everything from seed here on the farm, growing hundreds of flowers, herbs, and vegetables. I plant my seeds outdoors in a greenhouse with heat mats, humidity domes, and a space heater. I start so many seeds that my house would become a greenhouse if I started everything indoors, and I believe my plants are stronger growing in natural light and experiencing the diurnal temperature changes. Keep in mind I have infrastructure in place to make this possible, and I’ll highlight some ways to protect young seedlings below.
I started seeds like a madwoman, quickly outgrew the greenhouse, and started moving my sprouts to the hoop house. Everything was growing like gangbusters. Seeds need moisture, warmth, and light to successfully germinate and grow, and we had all of that in spades for the first two warm, sunny weeks of March. This was where my eagerness overcame my rationality. I don’t have enough heat mats for my 150+ seedling trays and my hoop house, though it retains better heat overnight because it’s connected directly to the earth, is much larger and harder to heat.
In mid-March, a cold front moved in, our kids had a busy week, and my little tomato sprouts were in the hoop house with only a space heater and a frost blanket. Overnight, the temperatures dropped to the low 20s and I lost three full trays of beautiful tomato babies. Important to note, my peppers were in the greenhouse on heat mats and unharmed. Even my eggplant, which is very sensitive to cold, was in the hoop house along with my tomatoes, but placed directly next to the space heater and miraculously survived. I’ve learned from past mistakes that a frost blanket cannot be touching the plants to be effective, and in the case of two of my tomato trays, I found it the next morning laying flat on the plants. This was my error- yes, I still make rookie mistakes! Lucky for me, I only lost three trays and even those had a few survivors. Three out of 60 ain’t bad.
Right now, we have inches of snow on the ground and even the daytime temperatures haven’t risen above 30 degrees. The plants might survive but they certainly aren’t thriving. I’m confident the greenhouse is fine but I still don’t sleep well through the month of March. I ordered new tomato seeds and will replant those I lost. Patience and learning, watch and wait. I can’t beat myself up too much because the sunshine in early spring is intoxicating and we are all eager to dig our hands in the earth again.
Ways to Protect Seedlings in Early Spring
Something to remember is that a single-layer greenhouse protects from light frost and raises the ambient air temperature by about 10 degrees. However, at night without the sun, that difference is almost negligible. I’ve discovered adding a shade cloth to the greenhouse is like putting a blanket over it. For extra protection, we tuck in a frost blanket INSIDE the hoop house, then drape cloths over the plants as well, propping them up with domes or sticks so they rest above the plants as much as possible.
If you have the budget, heat mats and space heaters are worth the investment. Heat mats raise the baseline soil temperature about 10 degrees, and an efficient and reliable space heater really retains heat overnight. I prefer my little 4 x 8 greenhouse over the 40-foot hoop house for starting seeds because it’s much more economical to heat, and you need to have heat if you’re starting seeds outdoors in March in western New York. I pull out my whole arsenal to protect sprouted seeds on nights when temps dip below 34 degrees.
Advice: When to Plant Seeds
So, when is the best time to start seeds? If proper care is taken, I’d still advocate that I wasn’t too early this year, especially since I sell our seedlings and need to have them ready on the early side. Our typical last frost date is around Mother’s Day in May, however last year, we had a late May cold spell so the general wisdom is to not plant until Memorial Day (I usually risk it starting the first week or two of May). Counting back weeks to maturity, 10 weeks before the last frost lands in early March. Here is my advice:
Seeds to plant 8-10 weeks before last frost:
- Perennial herbs (anything with super tiny seeds and/or woody stems when mature- thyme, mint, oregano, etc.)
- Perennial flowers (again, usually the smaller the seed, the longer the germination wait- achillea, monarda, rudbeckia, coreopsis)
- Cold-hardy plants (those that could overwinter, or sprout again every spring- snapdragons, onions + scallions, echinacea)
- Apiaceae family: celery, parsley, fennel- these need light to germinate and always seem to take forever to get going
- Peppers- I start them early because they grow slowly but they are very cold-sensitive and must be tended to with care
- Tomatoes- again, I start them early because I have a hoop house to hold them before planting them in the ground
Seeds to plant 6-8 weeks before last frost:
- Most annual flowers, such as strawflowers, ageratum, statice, celosia, gomphrena, etc.
- Most tender herbs, such as basil, cilantro, tulsi & dill (a member of the Apiaceae family but more sensitive and easy to grow)
- Brassicas- kale, broccoli, brussels sprouts, cabbage
- Tomatoes & peppers if you are growing indoors
Seeds to plant 4-6 weeks before last frost:
- Curcubits- cucumbers, squash, zucchini, etc. if you want to get a head start. They can and really should be direct-sown
- Leafy greens- swiss chard, lettuce, spinach (again, only if you want a head start or are succession planting)
- Flowers that can be transplanted at any stage, such as zinnias or cosmos
Direct Sow seeds:
- Spring vegetables (April): radishes, peas, beets, mustard greens, chard & leafy greens
- Summer vegetables (post-last frost, or mid-May): beans, curcubits, corn, carrots
- Cold Hardy flowers: centaurea, larkspur, poppies, bells, honeywort, nigella
- Easy to grow flowers (don’t waste your greenhouse space on these): sunflowers, alyssum, nasturtium, zinnias, calendula
This is of course, not a comprehensive list. But this is also not a comprehensive blog. Just some words of wisdom from a humble farmer. Best of luck in this growing season!