Experimenting with cloches

I spent the afternoon of Valentine's Day on the unromantic, but entirely necessary pursuit of creating a plan for my planting:

Luckily I'd already made a spreadsheet of all my seeds, dividing them into plant families and specifying how far apart the rows need to be, as otherwise I suspect I'd still be sitting stewing over it now. And while I was doing this, I discovered that two types of my seeds could be planted straight in the ground in February:

Well, you can't give a gardener news like that and expect her not to be straight out there with her trowel (or more accurately in this case, her fork, rake and hoe). So I now have a line of Ideal carrots and Scarlet globe radishes in the ground:

The radish packet mentioned that the early plantings do better in cloches, so I decided to experiment and see what effect various cloches had on both the line of radishes and the line of carrots. The glass bell jars in the pictures are purpose-made cloches that I bought on special from Sainsbury's last year. The rest are the tops and bottoms of plastic bottles cut in half or thirds (a mixture of thin table water bottles, a thicker mineral water bottle and even thicker squash bottles). I also left part of the row uncovered as a control - although it's not an ideal control, as part of it isn't very well dug, so the seeds may have more difficulty pushing their way through the turned-over grass than they do the better-dug and raked soil under some of the cloches.
It's hard running a properly rigorous scientific experiment when you have back problems: I've been restricting myself to three minutes of digging a day since a mere quarter of an hour of working the soil set my back trouble off and plunged me into a world of pain a couple of months back, and I had already seriously exceeded the three minute level again today to get even this much done, as I hadn't dug the area where the carrots belonged in my plan. Maybe I should have stuck to my original three-minute limit, but I've got to the point where I'm really fed up with doing the digging in 3-minute bursts and also it's been long enough for me to tell myself that because it's been a while and I've been digging regularly and going to the gym, things might have changed and I might be able to do some more. I didn't entirely believe myself on that one, but if you stick to strict logic when you've got chronic pain, your life choices can end up pretty grim and boring, so sometimes you have to risk your physical health for the sake of your mental health. (I say that like it's an aphorism, but actually that simply applies to me, now, with my current level of pain problems; better or worse pain and/or a different personality could change everything.)
But, at least I now have less of the digging left to do. Just today, my husband dug the patch on the left of the path. It took him about half an hour, which means it would probably have taken me 10 days or more. There are just little patches of grass left that still need to go in the area by the shed and in other parts of the area to the left of the path, sprouting from the vegetable beds like the last tufts of hair on an otherwise smooth back.