Depending on where you live, garden mums (on the whole) are winter hardy and will return each year. Mums will sprout in the spring and grow into leafy mounds across the summer, and then they start flowering anytime from late summer (late August) until frost.

I don't believe chrysanthemums are fully poisonous (like oleander or dumbcane), although mums can cause a skin dermititis in some people. They do have a fragrance in both their flower and their crushed leaves that some find "gross", which may be a good thing to smell-test on your children--crush a mum leaf and let them smell it (not fondle the juicy leaf). It the nose is turned away, I think they'll leave the mums alone if they come across them in the garden. Pets will trample a mum or anything else if there's a critter or ball under it in the pet's way. lol

In general, the really showy, large-flowering mums that are usually sold in florist shops are not as garden-hardy as the ones sold in autumn at garden centers and hardware stores.

If you go to the main Learn2Grow webpage and click on the "Plant Search" link, type in "Chrysanthemum" and you'll see our database entries for several varieties. Have a look!