I have my own tiller this year, last year I paid someone to till for me. It took him forever because he kept telling me it was to wet. It's been raining every day or every other day for a whole month. I have a small garden plot (25x25) and will be using a mantis. Any suggestions would be helpful.
When do you know if it's to wet to till?
Grab a handful of the soil and squeeze it. If it holds together in a solid ball it is too wet. It should be crumbly. It the soil contains much clay and you work it wet, you will get a mess of clods. Sandy soil you can work wet, but it is still not a great idea.
The "plop" test. Grab and handful and drop it on the pavement. If it goes PLOP, it's too wet.
Walk across the garden. If you get to the other side with mud soles on your shoes, it's too wet.
If you walk across the garden when it's wet, you will compact the soil. It's better to test the soil by squeezing it in your hand as Farmerdill says. Most tillers need additional traction, and work better when the soil is even drier than that. Also, I believe that it is better to till your soil in the autumn at the end of the garden season. You can add organic matter at that time and let it decompose over the course of the winter. It will be much easier and faster to get your garden growing in the spring! If you add organic matter now, be sure that it is already fully composted.