Age group(s) for this birthday party activity:
Preschool and Younger
Elementary School
Middle School
High School & Beyond

Birthday party planning information:
This works for any party theme:

Plastic 'frosting tubs' (Betty Crocker, Pillsbury, Duncan Hines) decorated w/stips of fabric, or paper...accented with ribbons, raffia, rick-rack, buttons, or other doo-dads n' thing-a-ma-bobs ;-)

You can use these to hold plastic forks, knives, n' spoons on your tables...or, you can put potted flowers inside.

If you begin early enough, you can Plant flowers from seed, or herbs (such as Chives, a fast-grower). In that event, poke holes in the bottom of the 'pot', and retain the Lid from your frosting container to use as a drip-catching 'saucer'.

Other suggestions or comments:
I just made 20 of these thangs for a chili feed. Ten were covered in red and white gingham checks, and 10 were covered with recycled Denim from old jeans. Both designs were accented with jute twine bows, w/fabric strips tied in... and a "Patriotic Pin" attached (from the Patriotic Celebrations page of What Works). Pinking Shears help to neaten the look, but aren't mandatory. They were verrry cool looking! If I had it to do over again (and 20 more dollars in my pocket...) I'd have used 'em to hold new spring Flowered Plants, but that's something to remember for Next Time ;-)

You are right; no sane person has 20 empty frosting containers stored up...but I find em' useful for many things (blush!)...and some weird chromosome from my margarine-tub saving grandma won't let me toss 'em. (This is the same Thrift chromosome that has me baking banana bread, and freezing it to last all of Eternity... ;-) Anyhoo...the frosting tubs are useful for stuff like home-made Play Dough. A decorated tub o' Play Dough would be a nifty party favor, and the covering on the tub can match your party theme. Try the recipe that uses KoolAid for color and scent (3 packets, as I recall).

You can also use the Decorated tubs, with lids, to hold a nice stack of Chocolate Chip Cookies! Great as party favors, or Teacher Appreciation gifts. Put the cookies in a Sandwich Bag before placing in the container, if it has been Handled much in the process of decorating/crafting.

Hint: make the strips of fabric slightly narrower than the fabric tub (I used an index card for a cutting guideline), and when applying glue, I had the best luck running the glue around the tub, top n' bottom, vs. putting it on the fabric. Then the fabric (or paper) lays on more neatly, and you just run a little bit o' glue on the place where it overlaps, to secure the edges.

I was really fond of working with the Gingham Checks, because the 'cutting lines' are woven right in ;-) Gingham also comes in many beautiful colors, pastels or bright, and even black and white. Good for anything from Over the Hill parties to Baby Shower themes.