Looks good & works like a champ, Steffen. Should be useful for a large swath of the gardening, landscaping, and related communities. Thank you for your efforts. I've bookmarked it.

Al

thank you!

To avoid confusion for people not used to the usda system yet, i guess i should try to say some general things about data interpretation: to measure hardiness by USDA zones is the international standart for this procedure, it is a good system, however one has to be clear about the data can only provide an impression of what will be hardy. it cant be taken 1:1, it is not that detailed and exact since it is only based on the average minimum temperatures in a zone but actually there are several other factors which also play a role and those will vary heavily. things like moisture, soil, sun etc.....

i hope my english was at least good enough to get the meening i am talking about...

Looks and works good. May I suggest a small cosmetic change: Use 'english' for locale selector instead of englisch :)

I checked your site and was surprised it showed some plants that "can not be grown in your area!" So I went down your list checking plants in my garden (well over 50, but I didn't count). Only one plant came out as being okay for my area. ALL the rest were "can not be grown in your area!" I suppose if I don't show the plants your website they should keep growing happily where they have been for years. I think you need to do more research.

could you please tell me your location + country and a few examples.

maybe something went wrong with the import

Well, here's an example when numbers lie. Meconopsis grandis is rated zones 3-9 I believe, but as a general rule, almost no one in the US could successfully grow this (yes I know some you pacific coast people can). It simply doesn't tolerate summer heat.

There's a lot more to the story than the numbers, I must agree.