Stressed-Out Seedlings

One project on this past week's to-do list was to get our broccoli and cabbage seedlings ready to plant outside. Remember how well they were doing sitting in the sunny window with their aquarium fertilizer? Here's a reminder:

So last Saturday I started setting the seed flat outside on the screened-in porch to get the plants acclimated to the colder air outside. This went well for the first several days, until we started moving them into the sunshine. Then one afternoon the wind (the goddamned wind here!) kicked up, and when I got home to the seedlings, they looked like this:

Some of what you see there are the initial seed leaves falling off, which is normal. A lot more of it, though, are wilty, shriveled leaves that dried out in the wind. It's not a total disaster, because they perked up again (not perfectly, but enough) over night when they were back inside and watered again. It is also bone-dry here, so the conditions were harsher than I realized (until the baby plants made clear their displeasure, anyway). 

The other problem is that I think I gave some of the nice, big leaves a sunburn as well. I was pretty careful about going slow on exposing the plants to the cooler temperatures, and I started them outside in the shade and shelter of the porch. But then I just moved them into the sun, thinking that they would be ok — not realizing that sun exposure needed to be gradual also.

The whole point of hardening off is so that the plants can build up a tougher outer layer on the leaves to protect them from drying out. It also helps to gradually expose them to wind so that stems have a chance to stiffen up as well. I didn't realize, though, that sunburn was a potential issue, and that leaves also need time to build up their chloroplasts in a different arrangement to protect themselves. A fascinating article about all the biology can be found here.

Anyway, here's a close-up of what I've got now:

As you can see, some leaves are beyond repair, and some of the tinier plants will probably not survive my error. Many of the bigger leaves are kind of crispy (or show white patches of sun damage). The hopeful spot here is that the newest of emerging leaves are smaller and thicker, which shows that they are acclimated to the harsher conditions. So these plants are probably slowed down for a while, but may make it with some luck (and no more harm by my hand). 

I doubt they will be ready to go to transplant this weekend, but we will try to get them in the ground on a cloudy day early next week. We'll also give them a row cover to try to offer a bit more sun protection in the beginning. I also expect to be finishing those rows with seeds, since so many of the seedlings will not make it. I suppose that will give us some good comparative data for next time on whether it's even worth it to start them inside, or if ones planted from seed do just as well.

I am really mad at myself for this, but I guess it can go in the "lesson learned" category. Our onions and leeks are due to go out next week, and I am being much more careful about their slow exposure to both cold and sun. I think that a two-week hardening off period will be more like it, and if that means putting onions and leeks out later than we wanted, then so be it.


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