how do I know when they're ready?

It seems like a silly question, even as I'm typing it, but...after I've planted something, particularly root veggies (even I can figure out when a pepper is ripe ), how do I know when they're ready? For example. I planted a square of radishes very early, so according to the seed packet, they should have been ready on the 14th of April. Surprise surprise, given how cool it was, they weren't. Well, they look a lot better now, much taller and more leafy, but (and again this sounds silly) I can't see the roots, so I don't know when they're ready! I can think of one obvious solution--dig one up and see. I can think of one "experience" solution--after I've had a few crops, I'll be able to tell by looking at them, from experience. But is there a better way, that doesn't require experience or digging them up to check? I'm thinking about those radishes, and the carrots, and the potatoes, the onions, the garlic, the ginger...

Just follow a stem down into the soil a little and brush it away to see the 'shoulders' of the radishes. If they have some size, pull it out. If not, re-cover just a bit, not a lot.

Other root crops its the same thing. Dig down in the soil with your hands and feel for the crop. Remove a bit of soil. Take a peek.

Even the experts need to check now and then.

I asked the same thing awhile back. I was told that a "ripe" radish would have about 1/4 of its "body" above the soil. Sure enough, a couple weeks later, it did. They were delicious!

MM makes this task so easy, too. Just poke your finger in and feel the top of the root. If it's the size you like, yank it! If not, leave it awhile longer.