Zone Cheating
 
(Other tropical links at bottom of page)
 
Growing Plants You Ought to Not Grow Because:
OK, now that we have established that you are either dumb, crazy, a risk taker, in serious self denial about where you live, or some combination of the above lets talk about increasing the odds of your success for a while, and I do mean for a while.  These techniques will work for most Zone 9b and Zone 10 plants for a few years until one of three things happen. 
OK, if I still haven't discouraged you, here is how you up the odds and make exotic tropical plants survive a mild winter freeze.  These may be used individually or in combination depending on the plant and common sense.  The chemical techniques might be good for an additional 4 or 5 degrees if done just right.  Most winters that is more than enough.  Adding the structure approach can be good for 10 degrees or more depending on your attention to detail. 
 
Cold Hardiness Links:
http://tct.netfirms.com/tropics/coldhard.html.  
 
Freeze Protection Links:
http://www.aces.edu/department/peaches/freeze.html
http://www.burger.com/freeze.htm
 
Other tips and hints:
1. Harden the plant for the winter and build some type of freeze-protection.
        Begin fertilizing with a high potassium fertilizer from mid-summer on
        Use a root stimulator product regularly such as SuperThrive or Schultz Root Stimulator
        Use a potassium foliar spray 24- 48 hours ahead of the freeze such as Dyna-Gro Pro-Tek
        Use an anti-transpirant spray such as WiltPruf
2. Make the most of the microclimate for the night of the freeze.
        Water all plants the night before the freeze
        Cover the entire plants with mulch or leaves
        Soil bank the main trunk as high as practical
        Depending on the plant turn on your sprinklers as a last resort
        Build a mini greenhouse or cover.  Do not use plastic alone unless you want a dead plant.*
        If the freeze is bad enough and the plant small enough, dig it up and pot it for the winter.
3. Take care of post-freeze trauma.
        Prune away decaying plant matter immediately
        Prune away non-decaying plant matter you suspect is damaged at the proper time for the plant
4. Always have a clone in the ready room*"
**The biggest advantage of all to Zone Cheaters is the fact that most tropical plants are easily rooted from cuttings or seeds.  As you are pruning, shaping and keeping plants under control over the spring and summer don't throw those cuttings away.  Use the cuttings to root new plants.  Worse case, the plant gets frozen, you have a free replacement plants waiting in the wings.  Best case with a mild winter allows you to either plant the additional plants in your garden, sell them, swap them for other plants with fellow gardeners, or introduce someone new to tropical plants in the garden.  It's a win-win situation.
 
*Many a good plant was not killed by a freeze, but by either covering a plant with plastic alone which will kill all foliage in contact with the plastic or by leaving the plastic sealed down the day after the freeze and baking the plant to death.  Temperatures in the 50s with full sun and clear plastic cover can easily kill a small tree, like a Citrus tree.  I have first hand experience.
Tropical Related
 
http://www.gingergarden.com/ - Got a soft spot for Gingers, check here.
http://www.lsuagcenter.com/en/lawn_garden/master_gardener/parish_lmg_programs/Greater_New_Orleans/Hot_Topics/Cold+Protection+Tips.htm Plant temperature tolerance information from Louisiana State University.
 
http://www.raingardens.com/sitemap.htm - Great site out of Houston. Pictures, information, links, lots of info here.  Be sure to check out Robert Riffle's Image Gallery too. Over 100 images of tropical looking plants growing in Houston, Texas.
 
http://www.rain-tree.com/plants.htm - Raintree's website is dedicated to providing information and education on the important plants of the Amazon Rainforest, therefore this section is the most extensive.
 
http://tct.netfirms.com/tropics/trophp.html - Set up a tropical paradise right in your own snow covered backyard. Palms, cycads, bananas, and other tropicals are yours to enjoy every day even if you live in Oregon, Canada, or northern Europe. Knowing the what, where, when, and how make it all possible. Let the Cool
 
http://www.urbanjungle.uk.com - Exotic plants in the UK. Welcome to the Urban Jungle website.
 
http://www.personal.u-net.com/~treetops/home.html - Another UK site with good cold hardiness info on palms.