Major climate shift for Georgians 

Hello Oleanders and Olive trees, time to move on Rhododendrons and Mountain Laurels, there is a change happening. Plants that grew in North Georgia years ago will be replaced by those that flourish to our south.

Here is some new data that will have an effect on what type of plants can thrive in metro Atlanta. The United States Department of Agriculture (USDA) has updated their Plant Hardiness Zone Map. For the first time since 1990, there is a shift nationwide, a shift toward a warmer climate.

This is not a discussion on the causes of "global warming", but just a reaction to the temperature change and the results that change is having on plants. On the Plant Hardiness Zone Map for Georgia, the range is Zone 6a in the mountains to Zone 9a on the coast. The zones are divided by the average annual extreme minimum temperature. For metro Atlanta that has changed and I think the urban heat island effect is main reason. Atlanta has moved from Zones 7a and 7b to a Zone 8.

What that means is that a new variety of plants will be able to prosper here. According to Deb Harrison of Habersham Garden Center in Atlanta, this will have a huge impact on new landscaping projects in the metro area. Deb says a whole new world of species will be popping up in the metro area.

New plants for Zone 8:

Arbutus unedo  (strawberry-tree)
Butia capitata (Pindo palm - zone 8b)
Camellia reticulata (Yunnan camellia)
Ceanothus impressus (Santa Barbara ceanothus)
Choisya ternata  (Mexican orange)
Cinnamomum camphora (camphor tree)
Eriobotrya japonica (loquat)
Fatshedera lizei (botanical-wonder)
Myrtus communis (true myrtle - zone 8b)
Nerium oleander (oleander - zone 8b)
Olea eurpoaea (common olive)
Olearia x haastii  (New Zealand daisy-bush)
Pittosporum tobira  (Japanese pittosporum)
Rhaphiolepis indica (Indian hawthorn)
Rhododendron 'Loderi King George' (hybrid rhododendron)
Rhododendron southern Indian hybrids (Indian azalea)
Viburnum tinus  (laurustinus)

For Zone 7, our old zone in the metro area, these plants will now prosper further north into the northern suburbs:

Acer macrophyllum  (bigleaf maple)
Araucaria araucana (monkey puzzle - zone 7b)
Berberis darwinii (Darwin's barberry)
Camellia sasanqua (sasanqua camellia)
Cedrus deodara (deodar cedar)
Cistus laurifolius (laurel rockrose)
Cunninghamia lanceolata (cunninghamia)
Elaeagnus pungens (thorny elaeagnus)
Ilex aquifolium (English holly)
Lagerstroemia indica (crapemyrtle)
Melia azedarach (chinaberry - zone 7b)
Osmanthus heterophyllus (holly osmanthus)
Pinus radiata (Monterey pine - zone 7b)
Rhododendron Kurume Group  (Kurume azalea)
Sequoia sempervirens (coast redwood)

It will be interesting on how this first major shift in plant zones in over 20 years will play out. Deb also tells me that she is seeing a change in the hardiness in plants that usually require "full sun". With a warmer range of temps, some sun plants are doing just fine in the heat of summer in partial shade. No doubt we are seeing a change, and plants, like humans, find a way to adapt. Peace.