Hi back Brain, I thank you for your help. We have roses all across the front of our house so I'll be keeping an eye on them to see how they like the extra Magnesium or not.
Your zone 9 would translate to our zone 3, and if the climate works out about the same as here, then you'll grow just about everything.
Australian is much drier than North America and it's climate zones are numbered quite differently, so if you're looking at Australian zones, you would need to deduct 6 to make your USA zones roughly equivalent our's.
The zone you're moving to.... North America Zone 9 .....is roughly equal to an Australian Zone 3. We're in a zone 2-3 at the moment, and can grow almost all but the tropical plants.
We can grow a wide variety of flowers, but orchids need to be indoors unless in a very sheltered position. We can't do Hibiscus or Frangipani..... Magnolias on the other hand, are magnificent.
We can't grow avocados or mangos here because they need a zone 4, but we can grow lemon trees, where-as oranges don't do well. We can grow apples, apricots, pears and cherries, but not bananas.
Potatoes and other root veges do well, but not the melons.... watermelon, honeydew etc.
Tomatoes, lettuces, beets and just about every other vege that I can think of does well.... all except those classified exclusively in the tropical variety.
I think the thing I noticed mostly between the zones (apart from tropical) was not the variety of plants, but rather the size they grew. For example: Daphne will grow in a zone 4 but it's a small bush, in a zone 3 it's medium sized and in a zone 2 it grows huge. There are lots like that.... they'll grow in different areas, but do better in some than others.
I hope that helps and I wish you luck with your move Brain. I'm sure you'll love gardening in a new climatic zone, where almost everything will do well!