READERS' PICK (TIE): If you wish to tiptoe through your own tulips next spring, you need two important items other than a ukulele. The first: excellent tulip bulbs. The second: excellent advice about how to prepare the bulbs for planting. This is what distinguishes the best garden nurseries from all the rest. The two favorites of the green thumb crowd are Catalina Heights Nursery and Mesquite Valley Growers. Both provide the goods and knowledge necessary to make your garden flourish. Tucsonans have long trusted the expert advice of the family-run Catalina Heights Nursery. They will sell you your desired plants, but only at the right time and with the right advice. We had trouble growing grass in a small patio, and were given an obscure variety that does well. This is the place to come with a problem. Walking through Mesquite Valley Growers is like walking through a botanical garden. Almost any variety of vegetable, flower or bush suitable for Tucson is available. And what's a modern garden without ornaments and garden architecture? Check out the supply near the entrance.