Damp-Off

The Future of First-Flower,  Writ Small

    On April 2, I planted the first seeds: anything requiring 8 weeks' head start on growing before the last frost (traditionally, Memorial Day here in zone 5, but I've often planted as early as Mother's Day —2 weeks earlier than that this year— and not been sorry). In three days, the first seedlings began to emerge. Because it was cold, snowy, and looked rather uninspiring outdoors, I can almost tell what hour they sprouted, since I was running down to the basement to check them 4 or 5 times a day. (We also have a new flock of 6 chicks in a makeshift brooder down there, so I had other reasons for vigilance, lest I sound a little too anxious...)
    Windowsill growing is just not the same as greenhouse growing, though. In the past, I've had better success at least setting up a germination box (two shop lights inside an open-sided wood box, draped in plastic sheeting to retain heat and humidity). The trouble is, using grow lights has a surprisingly significant impact on the month's electric bill. Space quickly becomes an issue, too. The only way to get enough of that is to use an unoccupied area like the basement, upgrade to more lights and more germination boxes ($$$), and hope the resident mouse—there always is one—doesn't develop an uncanny ability to suss out buried seeds. I've also had whole flats germinate, only to be bitten off by hungry rodents in the night. Air circulation and sufficient heat are problems as well. Too many years of these sorts of failure down-cellar made me hesitant to invest in the under-lights method. The only reason the pots of seeds went down there was for bottom heat.
    Bottom heat is magic. It speeds germination mightily, turning the soil into a comfortable nursery eager to rouse dormant seeds and get them stretching roots down and seed leaves skywards. For $50 plus electricity costs, you can buy a germination mat designed to provide the exact bottom heat needed. For that price, you get enough space for 2 flats. Now that's some expensive real estate! Back at the Shaker Village, I got around the need for bottom heat by providing it the very old-fashioned way: hot beds. A "hot bed" (not at all as sexy as it sounds) is simply a box frame with a transparent lid and no bottom (a "cold frame") set over a pile of decomposing manure. The biological process of microorganisms breaking down very nitrogen-rich materials like manure (or green vegetation) generates heat as a byproduct. Market farmers—especially in metropolitan areas where there was plenty of horse manure in the days before the internal combustion engine—took advantage of this free heat source to grow early-season vegetable crops "under glass."  It was the old-style equivalent of the season-extending hoop tunnel (and urban-gardening) now deemed so revolutionary. My set-up at Hancock Shaker Village included 3' high raised beds filled with barn waste and topped with cold frame lights (the glass or plastic lids) inside an unheated hoop house. I miss that setup mightily. Without a greenhouse or hot manure, how would I start my First-Flower seedlings?
    I scoured the local Habitat and Goodwill stores for used heating pads or electric blankets, which make a good, cheap substitute for those crazy-expensive heating mats, although the former are small and both have to be protected from the wet bottoms of pots somehow. Finding none, I settled on the one other source of free waste heat in our house: the top of our ancient boiler. We heat with wood, but the hot water still makes demands on the furnace several times a day, and being an old model, it leaks a lot of heat out the top. (Refrigerators used to work well too, in the days before eco-friendly models.) I was a little worried about melting plastic pots and starting a house fire, so I started with an elaborate arrangement of salvaged firebrick, an old cookie sheet, and frequent checking. Then I remembered how, in the process of setting up this safety-minded nursery, I had taken from the top of the furnace the paperwork left there in 1987 by the furnace guy. Unburned. If paper could age that long directly atop the boiler without igniting, couldn't pots full of damp peat? The pots went directly on the top of the boiler. Germination began.
    Without lights, the germinated seedlings had to go upstairs within the day so as not to stretch too far in search of sun. That's where the trouble began. The only  option was a South-facing bay window, as temps outdoors precluded use of the cold frame I had built (see the next post). That's when damp-off entered the picture. Ugh. Starting plants on a windowsill will give anyone the sense that they have a brown thumb.
     Look quickly at that olive dish full of baby Amaranthus 'Green Thumb' in the photo, and you see two-day-old seedlings full of promise. Look a little closer and you will see doom. A few of the seedlings are drifting sideways. Their stems have shriveled at ground level. They will die. Damp-off has set in. This disease, caused by just the unavoidable cool, damp stagnation of windowsill gardening, can wipe out an entire pot of starts in a few days. It helps to start with absolutely clean pots (I did), sterile medium (I did) and clean water delivered by letting it wick up from the bottom (yup). The best remedy once damp-off has set in is to separate the healthy seedlings out, plant them to individual pots as soon as possible, and get them into the sun and fresh air. I've had some luck watering with cooled chamomile tea, which is reputed to be anti-fungal. I didn't try that this time, but did try to get things separated and potted up and outdoors as soon as possible. This has meant many trips out at mid-morning and back in before supper with my burgeoning population of minute seedlings. But it seems like the situation is more or less under control. Round two of those first victims has just germinated today (2 1/2 weeks later) on the boiler. Weather is expected to soften anytime. Bloom where you are planted... please.