Magic Beans

We are currently harvesting 3 kinds of beans in our home garden:  yellow wax beans, green string beans and purple beans (the magic ones!)  They turn green when cooked, which is very interesting to my children.  A cool variety to try.  Easier for the kids to pick since the purple color really stands out against the green of the foilage.  Plus they look really neat in the pickin' pail.  I also found a kind of squash I want to try and grow next year...Zephyr summer squash...half yellow and half green.  You just don't see these kinds of things at your local supermarket.  I can't wait to see in my personal  raised plot at the church garden what is going on with my multicolored carrots!  Red, purple (can't remember if I planted any other colors or not).  There are so many varieties to explore that aren't the typical stuff you see everyday.  Yellow and burgandy tomatoes this year too.  My first "lemon boy" tomato is almost ripe.  I think.  How do you know when a yellow tomato is ripe?