Horticulture on the Internet, a Web site of North Carolina State University, contains a huge amount of horticulture information organized by topic area, allowing you to drill down to the info you are looking for. The information is gleaned from state universities around the country, so you can find regional as well as general advice. The volume of information on the Web can be mind-boggling, so this well-organized site is particularly helpful.
Clever Gardening Technique
Mix Tulips and Daffodils to Deter Rodents
Tulips are lovely, but the bulbs are a favored food for voles and mice. When you plant your tulip bulbs, interplant them with daffodils and alliums (flowering onions), both of which are distasteful to the rodents. Then, if you have enough bulbs, surround the whole planting area with miniature daffodils and low-growing alliums. Hopefully, visiting rodents will take a bite of an allium or daffodil, spit it out, and move on to greener pastures. Plant plenty of extra tulips, just in case, though.