At last we are getting toward the end of seedling season. As the little sweethearts get into the ground once and for all, we can finally sleep more soundly at night. No more rushing out in the evening to cover the coldframe in case it freezes, or in the morning to open them so that the coldframe-turned-solar-cooker doesn't burn our babies to cinders. No more worrying about germination temperatures, damping off, transplanting to bigger pots, etc. Hurray for spring!
Seriously, sometimes I thought our seedlings would be the death of me. For a start, we had to find a location to start them. This eventually was the bathroom, the warmest place in our largely unheated house. To help reach a reasonable temperature for seeds to germinate, we put a heat lamp over them. And this is how we got through the seedling season, doing pretty well for tomatoes, peppers, tomatillos and other nightshades, squashes and cukes.
But some plant were stubborn and simply refused to join the garden team in our amateurish setup. Bitter Gourds (Momordica charantia) and Malabar Spinaches (Basella alba) just wouldn't germinate. We ended up with one Malabar Spinach (nicknamed by Rosemary "Malibu Barbie", which probably accurately reflects the temperature sensitivity of the plant!). Not a Bitter Gourd on the horizon. Well you'll say, the most bitter vegetable in the world and a leaf veggie with mucilaginous leaves, not a huge loss. True. I'm not weeping for our loss. Just like I'm not too sad about the Snake Gourds (Tricosanthes cucumerina), which did germinate, but as soon as the weather got in the slightest chilly, and despite our diligence at covering the cold-frame at night, would drop dead one by one until we had none left. Another marginally edible squash that requires special attention and a 2 meter high trellis that we still had to dream up. Maybe it was being nice and saving us the work!
Then once they had germinated, our dear planties weren't out of the woods yet. This is when the dilemma of leaving them in the warm darkness vs. moving them to a sunny but cold window comes in. Never figured that one out. Imagine: you have a pot where you planted numerous Peruvian Groundcherries (Physalis peruviana). A couple of them start coming up. Do you leave them in the dark under the heat lamp for the other seeds to germinate, but most likely letting the early ones get tall and spindly and die, or do you move them to the window, where the other seeds will undoubtedly not germinate because of the cold?
"Damping off" is what you call it when the seedlings get all tall and spindly and thin near the base, finally collapsing or breaking off. It's caused by micro-organisms, fungi or oomycetes (that are not fungi, bacteria, viruses, plants or animals, which I can grasp, but something else entirely, which leaves me totally puzzled as to how to act toward them!). It happens most in moist, warm conditions with little ventilation. Exactly what our bathroom setup was. Our tomatillos got it pretty bad, but surprisingly they kept going, and even after having collapsed they just grew up straight again and now have nothing but a kink in the lower part of the stem to show for it.
So, I feel like I've learnt a few things and figured out what my ideal seedling setup looks like now: a greenhouse/coldframe with good ventilation, watering the seedlings from the bottom (a tray that can be emptied would be perfect), heating from below to promote root development (possibly using a hotbed with manure). Also, I'd prefer to use my own potting mix, with half garden soil and half sifted compost (as per Jon Jeavons' "How To Grow More Vegetables").
Still, how you accommodate a variety of plants with different favourite germination temperatures, I don't know. I mean, imagine you're growing cucumbers (favourite temperature: 15° to 18°C), tomatoes (favourite temperature: 20°C) , Peruvian Groundcherries (25°C), and snake gourds (25° to 30°C), what do you do? I tried putting the most heat loving ones right under the lamp and the less demanding ones further out, but still it's hard to control. And if you're using a greenhouse and/or a hotbed, then it must be really hard to control temperature. Also, does varying day/night affect germination rate?
Anyway, one thing we did get the hang of this time is to plant masses more than you'll need so you don't get a nasty surprise (which worked except for the plants that just plain refused to germinate -- cowards). Now the trouble is we can't bring ourselves not to plant any of them. I guess it'll take another year or a few to get the hang of thinning and selecting plants. But hey, one thing at a time.
5 comments:
Damping off is not what you say here. Damping off kills the plants in a very short time, hours or days. Usually the plants have some visible mold on them, but not always. Hygiene is the most important way to control damping off, and cleaning all your pots and other equipment in bleach and making sure your potting soil is sterile are both very important.
Spindly plants are (almost) always because of a lack of light. It's very hard to grow seedlings indoors without a light of some kind. You have to have a very sunny windowsill and you have to leave them there.
Keeping seedlings warm is not usually very important. I grow mine in an unheated room. You of course have to protect them from freezing. It is true some seeds won't germinate in cold soil (peppers for example), but this problem can be solved with a heated mat or tray (they usually sell these in garden centers), which usually use about 25w of electricity and only need to be on until the seeds germinate.
Ok good to know. I guess we had two things going at once then, the lack of light causing the seedlings to grow tall and thin, and the damping off.
We tried moving the seedlings to a bright sunny window as soon as they germinated, but as I say that was a dilemma when the seeds were temperature-sensitive and there were still a lot that remained ungerminated.
The cold near the window did kill off a few peppers and most of our first planting of peruvian groundcherries. I guess heated mats would have been good, but we would have needed quite a few!
Maybe above all the idea of separating the germinating area from the sun-lit growing area was not a good thing. But like I say, we feared that most of our plants wouldn't germinate (as it was some of the most heat-loving ones didn't).
Thanks for clearing that up, Patrick!
Yes, I agree...it's great to finally get to the point every gardening season where your plants are in the ground and you don't have to baby them so much two or three times a day!
Seeds can cope with a considerably lower temp after germination. I tend to germinate things in the kitchen in the warm, and then move them immediately to a lighter cooler place to grow on. If it's a windowsill bring them away from the glass overnight and put them back in the morning. A lot of trouble I know, but it's only for a few weeks until the weather warms up, good luck.
This year I tried sprinkling paprika on the compost surface to prevent damping off - it seemed to work...
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