NASA
Nasa: Climate Kids: Make Exploding Seed Balls!
Try this fun recipe for making and growing wildflowers right in your own garden.
Other
Kitchen Culture Kits, Inc.: Plant Tissue Culture
An excellent site for learning about plant tissue culture. Great visuals and easy to understand instructions. Lots of links to other good sources.
Texas A&M University
Wildflowers in Bloom: Wildflowers
Start wildflowers from seed, find out what your hardiness zone is, learn about seed germination and sunlight needs of plants. All this and more.
Texas A&M University
Easy Gardening. . . Beets [Pdf]
Let's you know all about this cool weather crop. Soil Preparation, fertilizing, planting, varieties, insect concerns, harvesting and more. Requires Adobe Reader.
Colorado State University
Gardening & Horticulture in Denver: Gardening With Children
The section on plant projects for kids has lots of hands-on ideas for studying plant biology. Activities are included for stages from seed germination to growth. Geared more to the younger student.