The short answer
No single distance suits every window and plant. Observe light at leaf height, including direct sun and obstructions, then compare the spot with the plant’s requirements.
Direction is a clue
University of Minnesota Extension recommends assessing light quality and duration before choosing plants. Obstructions matter. Its compass-direction examples describe northern-hemisphere conditions, not a universal room map.
Stand at the proposed plant position. Notice buildings, curtains and shelves between it and the window. Record the season and whether the day is clear or overcast.
Make a light sketch
Draw the window and proposed plant position. At morning, midday and later in the day, mark whether direct sun reaches that spot. This is an observation exercise, not a calibrated measurement.
| Time | What to note |
|---|---|
| Morning | Direct sun at leaf height? Curtains open? |
| Midday | Building or overhang shade? |
| Afternoon | Does sun reach a different shelf? |
Choose for the place
Compare your observations with species-specific care information. A room that looks bright to you is not a measurement of usable plant light. Minnesota Extension explains how insufficient light affects growth and when supplemental lighting may help.
Keep the sketch. If growth changes later, you will have a record to compare with a new season. A single photograph cannot establish the light conditions throughout a day.
A checklist to take with you
Tick items as you go. Checks reset when you leave this page.
Sources & scope
These original sources support the factual guidance above. Examples, diagrams and observation worksheets were prepared for this guide; they are not reports of hands-on tests.
Source check: October 23, 2026. Plant species and local conditions matter. This is general horticultural information.
Keep reading
A seasonal houseplant check-in without a fixed watering calendar →A yellow houseplant leaf: what to check before changing care →