What and when to plant in cold frames.

4K Shares

I had my first crackling fire in the fireplace last night. I was considering having it on the kitchen floor, but went with convention. And safety.

By tomorrow there could be a scorching heat wave with a humidex of bathhouse. You never can tell at this time of year. The weather's as unpredictable as the path of a butterfly. Or the success of a Will Smith movie.

Which makes cold frames a bit of a struggle because you have to actually pay attention to them. The beauty of the cold frame is that it's pseudo-gardening. There isn't a lot of work with them in the cold months. For the most part you just lift the lids and pick your lettuce or beets. But at this time of year you have to be reallyyyyy careful about making sure you vent them properly otherwise you'll end up with a big batch of cooked plants. So unless you plan on also throwing a glug of olive oil, salt, pepper and a toothpick into the frame, you have to make sure to keep an eye on the temperature in there.

For Spring and Fall plants like beets, carrots and lettuce the temperature inside the cold frame shouldn't get above 60 degrees. So if the temperature outside is 40 degrees, you need to vent your glass lights. If the temperature outside is about 50, you need to remove your glass lights. Put them back on once it's late afternoon and the sun isn't beating down on them. This will keep the frames warm throughout the evening and cooler night.

I planted 2 kinds of beets in August. Early Wonder beets which really did grow twice as fast as the other variety I planted.

I also planted Cylindrical beets, which instead of growing round, grow more like a carrot, without the tapering at the end. So all of your beet slices will be the same size.

I also threw some carrots in there in August and low and behold they've been a success. A HUGE success. I'll bet 10 of the 742 carrots I planted grew. I really should write Mother Earth News about this carrot miracle.

And then yesterday, I built another cold frame so I could plant greens. I ran out of wood so I scrounged around the house for anything I could build a square, 3 sided box out of. I came up with some very old bricks and an ugly storm window frame.

This frame isn't tilted like the other ones are, but since it's made out of brick it will hopefully retain heat a little bit better. This is all a crapshoot. I actually have no idea how any of these coldframes are going to do.

Laura, from Cubit's Organic Seeds sent me all the seeds one could ever need for planting fall and winter cold frame crops.

Would you like to save this stuff?

We'll email you this post, so you can refer to it later.

Anything you plant in a cold frame for fall growth takes much longer to grow because the conditions are cooler and there isn't as much sun. However, if you're going to grow greens in a cold frame, you're meant to harvest them when the leaves are only 3" or so high so you won't be waiting around for the plant to get to full mature size.

Mache is one of the best cold frame crops for this time of year. Lettuces grow well too and can actually freeze solid and still be fine to eat. You just have to wait until they've thawed out again (by late morning) before you harvest them. If you harvest them while frozen they'll turn to icky mush. But if you harvest them once they've naturally thawed they'll be beautiful, crisp, baby lettuce leaves. Even in January!

Baby greens seem to be able to withstand the freeze/thaw cycle but full sized plants do not.

I was on the ball enough in August to get a few carrots and beets into the ground but there's a lot more I could have planted if I'd had my act together.

At this time of year, if you do it *immediately* you can still be successful with several things in your cold frames. I say that with all the confidence of someone who has never done this.