A sunny corner may appear rather shady at nine in the morning, with just a few rays appearing by four in the afternoon. A garden bed alongside the house might get glorious early light, only to slip into shade by mid-day and be lucky to get even brief rays in the evening. One peek at a space and you might miss it all!
Mapping the sunny and shady areas in your yard on a simple site plan will reveal more information than you might imagine. The first thing to remember is that sun isn’t all about cardinal directions. Structures, mature trees and even the season have a lot to say about the light a given area receives.
Observe how sun filters in the yard at various times of the day and mark it down. You do not need to try and figure out exactly what time a given spot will fall into shade; the purpose is to identify which spots get bright full day, filtered or dappled sun, extended shade, or just a fleeting glimpse of rays. You might take photos of your site at varying times for reference down the road. Use colored pencils, or just draw different marks to indicate full sun and shade, etc. Take notes, don’t trust your memory and assumptions.
It may take more than one day to figure it all out. Trees and structures can throw unusual shadows, with very specific patterns. A mature tree might have bright filtered light at the edge, full shade under the canopy and bright rays slipping through gaps in certain spots. In winter you may get good light under the branches that get cast in full shade once a canopy of leaves emerges in summer. Fences, sheds and other structures can make shady or sunny spaces too. The angle of the sun changes during the year.
Once your site map is showing which areas get bright, filtered or very little sun during the growing season, cross check with your planting plans. You might realize that your plans for a sunny border along the path are a good fit for the location, but your shady bed by the house will need a different group of plants. Now is the time to find out what sun and shade a bed is getting, not once your plants are installed and you have to figure out what isn’t thriving. By doing a little detective work before you plant, you might save a lot of trial and error.