The power of micro climates
I took this photo today - what a wonderful example of microclimates affecting autumn colour. Even though it is actually winter, as I write this in late June, it is 21C in Perth. The picture shows the same type of bradford pear growing on opposite sides of the same fence.
If you look at the trees in front of the steel fence, you will see that they have both yellow and green leaves but no red or orange. These bradford pear trees usually colour up well even in our mild climate. If it's really cold at night or in the mornings, they will turn red instead of yellow or orange. Generally with autumn colour, the colder the conditions, the redder the leaves.
Now look at the remaining leaves on the taller trees behind the fence. You will see that they are largely orange or red in colour. The reason for this may be partially to do with the fact that they are older than the ones in front, but largely it's because they are in the cold wind and as they are taller, don't have the radiant heat of the steel fence on their leaves to keep them warm.
One of our constant challenges here at Garden Deva is designing beautiful gardens around these radiant heat producing steel fences. We completely understand the rationale behind installing these fences as they are maintenance free, reasonably priced and long lasting. Unfortunately in summer, the plants next to them often cook in the baking Perth heat unless they are extremely tough like oleanders or bougainvilleas.
Cladding steel fences with non heat conducting materials such as good quality brushwood, timber or bamboo screens, or planting trees nearby to shade the plants are some suggestions recommend to clients if they want to have an increased plant palette to choose from to screen their neighbours and fence.
So, when you are next choosing a fence for your boundary, consider timber or Slimwall (a fibre cement product which looks like brick but has none of the heat conducting qualities). Your plants will be grateful.