Draw the spaces you want to use
Sketch beds, pots, seating, paths, fences, buildings and trees. Divide the garden into small areas you can recognise on site. A bed next to the house may behave very differently from a pot near the back fence.
Record direct sun on a clear day
At regular intervals during the period you care about, note which areas receive direct sun, partial cover or shade. Use the same observation points and write down the date and local time. Record clouds separately so weather is not mistaken for shade from an obstacle.
The Royal Horticultural Society's shade guide describes different levels of shade and their implications for planting. Its midsummer sun-hour categories are a useful guide, but plant suitability also depends on climate, soil, moisture and exposure. Check advice for the specific plant and your region.
Repeat across the growing season
One clear day is a snapshot. Sun angles change through the year, and deciduous trees cast different shade when in leaf. A spring patch suitable for early growth may be shaded later. Observe the seasons relevant to the plants you intend to grow.
Use building shadows to investigate large obstacles
Coffee in the Sun can show estimated shadows from mapped nearby buildings at different dates and times. It is useful for exploring why a neighbour's building might shade one part of the garden in winter.
It does not model trees, fences, awnings or terrain. Small structures and building heights may also be missing or inaccurate. Do not turn its sun-hours result into a plant-specific guarantee: observe the actual bed, including vegetation and local obstacles.
Match the planting to the evidence
- List the observed light pattern for each area.
- Record soil and moisture conditions separately.
- Choose plants whose regional guidance fits those conditions.
- Use movable pots to test an uncertain position before committing to a large planting.
- Keep a record and adjust after seeing a full growing season.
Plan seating separately from planting
A vegetable bed's ideal exposure may differ from a comfortable reading spot. Check seating at the time you use it, and keep a shaded alternative for warm conditions. For a covered outdoor area, read how overhangs change sunlight.
On a balcony, use the balcony sunlight guide: pots behind a railing or under a slab can receive much less sun than the open ground nearby.
