In our small urban yard I've relied a lot on taking pictures.

When it rains hard to see where things pond up I take pictures so I can fix the drainage of these areas.

I noticed a few plants I thought were getting 6-7 hours of full sun weren't doing well. So I decided to take a photo every hour on the hour to see exactly how many hours each area of our yard gets. This may be information that could save you time in the future so you don't have to move trees or other hard to move plants after they are planted. The added benefit of these shady spots (really 4-5 hours) is that a lot of the cold weather crops get started before the leaves are on the trees and are growing longer before they bolt.

I've run into another interesting gardening issue. It has to do with the changing sun path and our espaliered fruit trees getting enough light throughout the day. The Sun path changes throughout the year (and is marked by the soltices) its illustrated on this chart for 36degree North Latitude. (The roman numerals on the left and right are the Months and the arcs are the sun paths on the 21st of those months.)

http://www.flickr.com/photos/20378685@N00/5880523803/in/photostream

The issue is coming where we have tried to espalier trees along a fence line that runs West/East, similar to how everyone mentions (in the UK.) The espaliered trees don't get sun until 10:30 when the surrounding trees are leafed out (this is a specific site condition for us.) The light at the end of the day is more in spring and fall than in summer due to the position of the sun setting (further north) which causes the fence to actually shade the trees.

In my example if the espalier tree was in the center of the circle on the chart (North is up) I can figure out how many hours that tree could get assuming I knew when the shadows occured at certain times of the day (that's where the photos come in.)

It turns out by living at our Latitude (36d N) and not in the UK (Latitude 54d N) that growing espalier trees against a West/East Fence would be limited to a fence that is in full sun from sun up to sun down to get the right amount of daylight.

That's a good example of how growing things in different countries, or even regions can change so drastically and give entirely different results.

I thought I would share in case anyone was considering growing espaliers in the South.

Another good tool for maping and showing shadows is Google Sketchup. You can find your land on Google Earth and Pull it into Google Sketchup Outline your existing buildings and pull them up to the correct height and it will automatically make shadows all you have to do is adjust the month and time of day. It has it's limitations because it's hard to model tree shadows. But this way is easier to visualize everything and see exactly how the shadows will effect your property.