First things first, our plant ratings are based upon climate data research.  If this were Rocket science, then perhaps we could be more specific as they use controlled experiments.  For me, I use a combination of factors and some have been personal experience from actual tests I have conducted at our nursery. I have also factored in suggestions, experience, etc, from other growers in the USA. I have reviewed climatic information in Australia where these Eucalyptus species are found. Eucalyptus species are generally not found in just one isolated location and this holds true for many of the Australia natives. I look at maximum and minimum temperatures recorded for about 700 different reporting stations. This data goes as far back as the mid 1800's for some areas and usually included lowest and highest temperature ever recorded, altitude, annual rainfall, etc.

I also looked at AUSLIG (Australian Surveying and Land Information Group) maps that show recorded locations of Eucalyptus species and tie these in with the weather records.

When you look at the wide range that some of these species are found; it's difficult to say with 100% accuracy that something will or will not survive in your zone. I tried to utilize at least three different locations, average out the temperatures and come up with an "average" low rating. We have not even started to use the USDA Heat Zone ratings, nor, utilize the annual rainfall that was recorded for each station.

I might rate something hardy in Zone 9, yet you live in Zone 7 or someone else says it's hardy for yet a different zone and the confusion never seems to end.

Seed that comes from colder areas are more likely to produce a shrub or tree that is more cold hardy. As a commercial nursery grower and Australia seed importer, I can ask for seed from a particular location, but there is no guarantee that what we received came from the desired location. In dealing with the larger Australia seed companies, they have a reputation to uphold and they are usually pretty good in filling our needs. Still, some seed we receive has no collection location data.

The Australia climate is not like the USA climate.  California has about the closest thing as evidenced by the number of Eucalyptus species growing there.  For those of us in the "other 49 states" and for me in central Virginia, there are only a few Australia plant species that might survive here but I keep trying different plants, seed lots, etc. to see if I can be successful with any of these.  It's a real challenge, yet, I am not getting discouraged easily.  The only thing that beats a failure is a success and at least I can have fun while experimenting.

I could have used the "spin the bottle" technique or based my recommendations on how shiny a frogs back is, better yet, I probably should have asked one of those "Fortune Tellers" for the correct answer as you know they would never tell you a lie.  Trying to compare our climate with that of Australia, our winter moisture with their droughts and any other multitude of unknown factors and all we do is end up making an educated guess.  It's a guess, plain and simple and the only thing you can do is try for yourself and evaluate your results.  If you consider all Australia plants as an annual, then you will probably not be disappointed.  If by some some strange miracle it lives past the first year, then keep your fingers crossed and hope for the best!  Some of you in warmer climates will definitely have success, others, well, you are probably like me and we keep trying.  We can blame it on the weather (always a good choice), blame it on the the famous "groundhog" day, or, perhaps you can just blame it on me.  Go ahead, I've had my share of it!  Heck, I can even blame it on some of the care (or lack of) that you gave it. 

It doesn't foster good customer relations if you expect miracles from us.  If you give us a fair shake, then I'll try to help where I can, but I can't guarantee any specific plant will live for you.  If you think of an Australia native plant as an annual and it lives longer, be happy.  If it doesn't, then go back to the paragraph above and chose your best option for spinning the bottle, searching for a frog, or you can elect to spend your money with a fortune teller and perhaps pick up a few stock tips as well.

For me, I'm doing everything I can to ensure you will be successful.  I have a degree in horticulture, but sorry, I just never quite made it to the "Rocket Science" classes because all those botanical terms and foreign languages (chose Latin, Greek, Zenus or Hippie) still jumble around in my head to this very day! 

We search for the most "cold hardy" provenances for our seed.  We do actual field growing trials here in our Zone 6.  We experiment with new products each year.  We try different methods of production. We try bog germination, electric heat pads, misting timers.  We try new media mixes, seed enhancers like "smoke water", cold treatments, heck, I've even soaked seeds in the back of the toilet tank to wash out inhibitors.  The fact remains we are not immune to failures or successes and we are willing to try different things.

If I have not totally turned you off to trying Australia natives by now, then read on.........

I recommend you plant out early in early spring or fall. This gives the plants time to develop into the surrounding soil and the root system is more established prior to winter onset. With fall planting, the watering requirements are less. If we don't have a very cold and prolonged wet winter, we usually have good results. (The year 2001 has brought us new challenges due to drought!)

Survival of the plant still depends upon the root system, a plant with more roots has a better survival rate.