Excellent site which offers information about native plants and their effective use in the landscape. The Dyck Arboretum at Hesston, KS also offers many worthwhile seminars and events.
Lady Bird Johnson Wildflower Center
Excellent information about native plants and related educational opportunities at the facility in Austin, Texas.
Missouri Botanical Garden
An abundance of information about plants and their care as well as related issues. The Missouri Botanical Garden in St. Louis offers many outstanding classes and events which are also listed on this site.
The site for the botanical gardens of Kansas City! This site offers information and inspiration for gardeners everywhere. Powell Gardens' many classes and unique events are also listed on the site.