No light? Then sow later!

Green thumbs up

To the new catalogs and emails about plants and seeds all over our desks, end tables and inbox.

The urge to buy a few - no, a bunch! - is always there. This year more than usual we feel an urgency to order, since people living the shut-in pandemic life turned to gardening. Seed- and plant sales in 2020 hit levels never seen before, with companies doing five- and six times their normal business, selling out of items just days or even hours after offering them for sale. That trend may well continue. Shouldn't we order right now, before "Sold Out" becomes the most common plant description?

Green thumbs down

To the sow-too-early trap.

Yet if we order right away the too-early trap awaits us. We've been there before, and recall the refrigerator stuffed with bare root plants while we waited for the ground to thaw, and every table and countertop holding flats of seedlings we couldn't resist starting once we had the packets in hand.

We still love the paper copies best. Those settle on the nightstand so we can read them in bed then dream of new gardens.

We still love the paper copies best. Those settle on the nightstand so we can read them in bed then dream of new gardens.

Contemplating shortages

Hmm. Maybe the pandemic push won't be so big. We imagine all those novice seed-sowers experienced some failures, as we all do. Perhaps those without The Passion have been discouraged, will turn to other pursuits and our orders will be fulfilled.

Such a dilemma! Especially as we want the increased gardening to continue!

Rather than chance it, we've ordered. At the same time we pledged to not start any more seed than we have light to raise.

In 2020 seed- and plant companies saw all time record sales as pandemic-bound people turned to gardening. We wish the new gardeners well yet we wish in 2021 they will not buy out what we, too, want to grow!
Raise the light to remain just inches above the bean, starve the tomato seedlings and others below.

Raise the light to remain just inches above the bean, starve the tomato seedlings and others below.

Light lacking

So many people start seed early, envisioning large, lush plants ready to set out in the garden in May. So often what they produce instead are spindly, weak seedlings. The missing factor is light.

Windowsills don't cut it. Winter light is too weak, less than a tenth what a young sprout needs. Worse, winter hours of light are too few, so the seedling spends too long each day creating dark phase compounds in its cells. It's a problem, too, that the window glass reduces light even further and most windows are too generous with cold air.

Forget windowsills

We leave windowsills free. As soon as seedlings germinate we put them two inches below a fluorescent tube. Grow light, shop light, spotlight, it doesn't matter so long as it's two or three inches away, no further, and does not emit heat.

We check the distance every day and raise the light fixture as the plants grow. A turning point comes when the sprouts are more than three inches tall. Since light intensity drops off dramatically with every inch of distance from the bulb, three inch seedlings are in danger of becoming puny at the base.

The light should be just a couple inches above the seedlings.

The light should be just a couple inches above the seedlings.

Return to the cold frame

We may relive old times this year and build a cold frame, a place where we can put sprouted flats of plants into outdoor light. They bulk up in that greater light. Sol's 1,000 foot-candles outshine all but the strongest industrial fluorescent array. At the same time, growing in cool air promotes stocky growth.

You can make a cold frame very easily with straw bales or concrete block forming the sides and an old window laid across the top. You can go all out and build a south-slanting, Plexiglas-topped box sized for 12 flats, with special heat sensing hinges that crack the top when the air gets too warm inside. You can add a heating cable on the ground, cover it with a layer of sand, and have a hotbed.

Can't picture it?

Many gardening encyclopedias include illustrations to help you build a cold frame, or the building plans. Here are two on-line from Cornell's Extension, and from Fine Gardening magazine.

Or wait, sow smart in April

Or you can wait until April to sow seeds, and in May put each one out where it will grow. Save plastic milk jugs 'til then. They make great hot caps to protect new seedlings from cold air. Cut off the bottom of the jug, and set it over the seedling. Remove the cap to keep the enclosure from overheating on sunny days.

Other pages here at GardenAtoZ.org to help you choose lights and sow seeds

Growing Vegetables

 When shopping for grow lights

Good news, no need for special bulbs