Zone question

Hello there one and all,
I have a simple question, with a most likely obvious answer, however I have to ask nontheless; If a plant is 'hardy to zone x' could it survive in another higher rated zone, or would it die? I am new to plants and gardening and didn't even know zones existed 'til I started scouring the labels on the plants!

Hope this post finds everyone well, and with very green fingers

WildRose

The simple answer is yes, something that's rated to zone 5 would survive the winters in zone 6, 7, 8, etc. The longer answer is that the zone rating is only based on winter cold and nothing else, and there are many other variables that go into whether or not a plant will survive in a particular area (summer highs, humidity, rainfall, soil type, etc) so it pays to do some research on whether the plant will be happy in those other conditions that are present in your area rather than just relying on the zone.

Thank you for such a halpful answer. I am sorry my reply is so late... 101 things have happened since I was last able to get online. Thanks a lot and with any luck my roof terrace will be great in the summer!

ecarne, it's not just the winter, it's also the heat range, and whether something is tropical or not. Some plants from up here could or could not survive Ca. Some plants that stay indoors up here could go outdoors down there. However some could actually stay indoors down there especially if they can't stand too much heat. It's not just winters, it's summers too. We don't get as hot as some places do. However you don't gt as cold as we do. And as for the United Kingdom, I wouldn't know.

That's exactly why I gave the longer explanation as well as the shorter one--if you read my post you'll see that I mentioned summer highs, rainfall, etc as other factors that you have to look at in addition to the zone rating. But the UK doesn't get very hot so summer heat is definitely not a factor in this case.

You also have to take into consideration zones which have significant snow fall. Snow is a natural insulator that keeps the under ground warmer than the actual temperature outside. This means that the roots are not exposed to the temperatures that the hardiness zone number would indicate.

Other risks to plant survival but not considered in the hardiness zones are soil moisture, humidity, the number of days of frost and the risk of plant deadly cold snaps.

Day length is another factor to be considered. Many plants will survive in different zones, but because of varying day lengths they may not flower.

And the zone hardiness does not even consider the heat and humidity when determining zones. This is one huge drawback to the system.


This message was edited Feb 4, 2009 10:30 AM