Here is something I made up for L to work on his fine motor skills. I poked holes in a box. It's not pretty, but it works. You can decorate yours more if you wish, at least mine is green like grass.
Next I made some flowers with pipe cleaners. Very basic, but I did have to change them a little. At first I tried to make leaves on them, but I figured out in order to make them a little more sturdy and easier for L to get them in the holes without them bending, I just bent the pipe cleaner in half and twisted it around itself over and over.
That's it. Then you just poke the flower stems in the holes.
Here are some photos of L playing with it.
There are lots of variations with this activity. You can make as many or as little flowers and holes as you want and put them farther apart or closer together. Whatever you think is right for your child. Have fun and happy Spring!