Zone 9 Information
Zone 9 is found in the lower sections of Florida, Texas, and Mexico. California and Arizona are primarily comprised of Zone 9. This zone can be hot and humid in most places during a good part of the year. Arizona tends to be a drier heat. Take care to keep your garden watered in the blazing summer heat. You'll find many plant choices available for this zone. Even a few bulbs, such as tree peonies, can grow well in this warm climate. They need at least two weeks at 35 to 40 degrees to bloom.
Zone 9 was divided in 1990 into two areas by the National Arboretum to provide gardeners with even more environmental detail: 9a and 9b
9a - Minimum temperature of 20 to 25 F (-3.9 to -6.6 C) Places like Houston, Texas and St. Augustine, Florida.
9b - Minimum temperature of 25 to 30 F (-1.2 to -3.8 C) Places like Brownsville, Texas and Fort Pierce, Florida.
Here's a partial list of plants that thrive in Zone 9
Coleus(Coleus x hybridus "Carefree Mix")
Leopard's Bane(Doronicum cordatum)
Bearded Iris(Iris x germanica 'Blue')
Big-Leaf Hydrangea(Hydrangea macrophylla 'Glowing Embers')
New Guinea Impatiens(Impatiens hawkei 'Satellite')
Pink Jasmine(Jasminum polyanthemum)
Chinese Foxglove(Rehmannia elata)
Blue Palo Verde(Cercidium floridum)
Jerusalem Sage(Pulmonaria saccharata 'Sissinghurst White')