It sounds lame, but one of the things I look forward to in Spring is taking the kids to our local garden center and picking out what to grow.
They like getting their own plants, getting to watch and eventually eat some of what they helped grow (although this year we really only had some crazy peppers and onions survive, and none of them were thrilled with those). I'm always on the look-out for family-oriented gardening stuff, and without any doubt, THIS IS THE BEST BOOK IN THAT GENRE I HAVE EVER COME ACROSS.
It covers planting, yes, but it covers playspaces, bugs, even sensory plants. It has tons of beautiful illustrations and it speaks well to elementary-age kids and tweens but you could happily read sections of this to a preschooler. I also learned a great deal from this book (I have been around and loved earthworms forever, but have never seen a picture of their poops, so there is that) and I'm excited to make our gardening trips a year-round thing. It would be great to follow some of the suggestions in this for letting the kids design their own gardens and exploration spaces as well.
Overall, I can not recommend this enough to families who want to make gardening more of a part of their daily lives. This is excellent and thorough and should be the first thing you reach for reference for that.
*I received this ARC from NetGalley for this review*