Growing Zones

[sebastian]

Okay this may have already been said and talked about?

Ive never needed to take an interest in climate zones due to living/gardening in a subtropical climate.

But now looking around it seems a bit of a mess with and zones not really a realiable source of what you can grow.

Why I say this is Max lows are fine to go by in one sence to stop planting plants that will die in the first chill.

But what about the heat factor??? the thing that makes plants grow???

Take for instance coastal Melbourne in victoria Australia it sits in a temperate climate with long cold winters but the lows rarely if ever go below 0C the summers are short and vary from one day being 17C to the next 47C.

Then if you go a thousand or so KM north past the sunshine coast to an area such as Gympie it sits in a area called sub tropical.

However it's winter nights and early winter mornings regularly receive temps lower than coatal melbourne, although it must be said by 10:00 the same morning the temps are often 20C.

The summers are very long without many days above 35C

Correct me if im wrong, but i beleive both Zone's are viewed as the same or Gympie's technically possibly being rated lower.

Offcourse in reality Gympie is much kinder on palms with huge Royals,foxys,Bizzys etc all growing like no tommorow with the constant day warmth factor.

This is just an example.

So is there another way/guide/zone thingy to work out an areas growing climate based on not just the cold factor but the warmth per days per year factor???

[Don Little]

sebastian,

There is also something that was new to me that was discussed in another thread called heat zones based on how many days a year a particular location goes above 80 degrees F or 26.6 C.  It was in the climate forum a few months back.  will have to look for it.

[chris.oz]

(sebastian @ Jan. 09 2007,04:32)

QUOTE

Okay this may have already been said and talked about?

Ive never needed to take an interest in climate zones due to living/gardening in a subtropical climate.

But now looking around it seems a bit of a mess with and zones not really a realiable source of what you can grow.

Why I say this is Max lows are fine to go by in one sence to stop planting plants that will die in the first chill.

But what about the heat factor??? the thing that makes plants grow???

Take for instance coastal Melbourne in victoria Australia it sits in a temperate climate with long cold winters but the lows rarely if ever go below 0C the summers are short and vary from one day being 17C to the next 47C.

Then if you go a thousand or so KM north past the sunshine coast to an area such as Gympie it sits in a area called sub tropical.

However it's winter nights and early winter mornings regularly receive temps lower than coatal melbourne, although it must be said by 10:00 the same morning the temps are often 20C.

The summers are very long without many days above 35C

Correct me if im wrong, but i beleive both Zone's are viewed as the same or Gympie's technically possibly being rated lower.

Offcourse in reality Gympie is much kinder on palms with huge Royals,foxys,Bizzys etc all growing like no tommorow with the constant day warmth factor.

This is just an example.

So is there another way/guide/zone thingy to work out an areas growing climate based on not just the cold factor but the warmth per days per year factor???

Quite so Sebastian,  based on USDA,  our site in Bayside Melbourne is 10a verging on 10b,  but Roystonea will not grow here since there is not enough summer heat. [ even though it sometimes gets to 43C for a few hours on a summer day]

I was also staggered to find out that the winter lows on the Atherton tableland can be lower than we experience in bayside Melbourne.

Palms which enjoy cooler nights and survive long cool winters do grow here and there are many fine old examples of Howea growing in gardens here.

The best way to rate an area for palm growing is by seeing what palms will grow there.  There needs to be a set of "yardstick" palms to indicate the growing conditions.

eg Equatorial PalmZone: Cyrtostachys,

Tropical PalmZone: Cocos,  

SubTropical PalmZone: Dypsis lutescens,  

Warm Temparate PalmZone:Howea, Archontophoenix,  

Cool Temperate PalmZone:  Butia, CIDP

Cold  TemperatePalmZone: Chamaerops humilis

[ghar41]

(sebastian @ Jan. 09 2007,04:32)

QUOTE

But what about the heat factor??? the thing that makes plants grow???

I have found the Sunset Garden Book guidelines to be much more useful here on the Western US for this very reason.

For instance, it separates Zones 16 and 17 here in Northern Ca. largely based on the amount of heat in these zones.

[spockvr6]

(Don_L @ Jan. 10 2007,00:53)

QUOTE

sebastian,

There is also something that was new to me that was discussed in another thread called heat zones based on how many days a year a particular location goes above 80 degrees F or 26.6 C.  It was in the climate forum a few months back.  will have to look for it.

I dont have a USA map (or know of where one could be found), but here is the heat zone map for FL courtesy of the Florida Climate Center.