What does bright indirect light mean?

A spot that gets plenty of daylight without the sun's rays landing directly on the leaves. The RHS describes it as bright light that doesn't cast a sharply defined shadow. Typically that's in an east or west window, or set back a bit from a south window.

Is a north-facing window enough for houseplants?

For shade-tolerant plants such as ZZ plant, snake plant, and peace lily, yes. The Missouri Botanical Garden classes a north window as low light (25 to 100 foot-candles) for most of the year. Light-hungry plants will grow slowly and stretch there.

How many foot-candles do houseplants need?

UF/IFAS and University of Maryland Extension define low light as 25 to 100 foot-candles, medium as 100 to 500, and high as 500 to 1,000. Direct sun is over 1,000. Other sources draw the lines a little differently, so treat these as rough guides.

Are phone light meter apps accurate?

Roughly. A 2022 study from the University of Maribor found phones aren't reliable for precise measurements without calibration, but most give meaningful data for home use and plant growing. Use one to compare spots in your home rather than to chase an exact number.

How do I know if my plant isn't getting enough light?

It stretches, with long gaps between leaves, leans toward the window, makes smaller and paler leaves, and grows slowly. Variegated plants may turn greener.

Can a houseplant get too much light?

Yes. Direct sun through glass can scorch leaves, leaving bleached, brown, or dead patches. Shade-loving plants are the most sensitive.

Houseplant Light Guide: Window Direction, Distance, and Foot-Candles

Light is a houseplant’s food supply. Perfect watering and a pricey potting mix can’t make up for a spot that’s too dark. The catch is that we’re bad at judging it: UF/IFAS points out that our eyes are not very accurate tools for measuring light intensity. A room that feels bright to you may give a plant only a fraction of what it needs.

Clemson HGIC puts it in numbers: the interior of a well-lit home is often under 100 foot-candles, while outdoor light on a clear sunny day can exceed 10,000. That’s a hundredfold difference.

Foot-Candles and Lux

US sources measure light in foot-candles (fc or ft-c). Most meters and phone apps can also show lux (lx), the metric unit. Iowa State University Extension gives the conversion: 1 foot-candle = 10.764 lux.

How Much Light Do Houseplants Need?

UF/IFAS and University of Maryland Extension use the same ranges, measured at midday at leaf level:

Category	Foot-candles	Approx. lux	Typical spot
Low light	25–100	270–1,100	Far from windows, or heavily shaded
Medium light	100–500	1,100–5,400	Near a window with no direct sun
High light	500–1,000	5,400–10,800	Near a window with some direct sun, softened by sheers
Direct sun	Over 1,000	Over 10,800	Unobstructed window, four or more hours of sun

Clemson HGIC draws the lines differently. For low-light plants it gives a 100 fc minimum with 75–200 fc preferred for good growth; for medium-light plants, 200–500 fc preferred. It also notes that about 100 fc for 12 hours a day only maintains plant quality for a year, and foliage plants need at least 200 fc for 12 hours a day before fertilizer does them any good. In short, a plant in dim light survives rather than grows.

Treat all of these numbers as rough guides. Ranking the spots in your home from brightest to dimmest matters more than hitting an exact figure.

Window Direction

These descriptions apply to the Northern Hemisphere.

Window	What it offers	Source
South	Brightest, most intense light all day	NC State Extension; Missouri Botanical Garden gives 300–1,000 fc and about five hours of direct sun
West	Bright light by day, strong afternoon and evening sun, runs hotter	NC State Extension, Missouri Botanical Garden
East	Direct morning sun, bright indirect light the rest of the day	NC State Extension
North	Lowest light, indirect all day	NC State Extension; Missouri Botanical Garden classes it as 25–100 fc most of the year

Clemson HGIC’s placement advice follows the same logic: high-light plants near west or south windows, medium-light plants within several feet of those or in east windows, and low-light plants several feet from east windows or in north windows.

Surroundings change everything. Trees, neighboring buildings, a balcony overhead, awnings, and sheer curtains can turn a south window into a low-light spot. In a Penn State Extension article, the author’s south-facing windows were blocked by tall buildings, which left them with medium to low indirect light.

Distance From the Window

This is the factor most people underestimate. NC State Extension notes that light intensity drops rapidly as you move away from a window: a south window with strong direct light can become a low-light area if a plant is moved just 8 feet back.

Illinois Extension gives these rough distances:

Target light	North window	East/West window	South window
Low (~75 fc)	A few feet away	3–10 feet away	15–20 feet away
Medium (~150 fc)	Directly in front	A few feet away	3–10 feet away
High (~300 fc)	Not listed	Directly in front	Up to 5 feet away

The Missouri Botanical Garden adds that anything beyond about 8 feet from east, west, or south windows is generally low light, while east and west windows, and spots at least 2 feet back from a south window sill, get indirect light of 100–300 fc.

Moving a plant a few steps often fixes more than swapping it for a different plant.

The Shadow Test (No Tools Needed)

Around midday, hold your hand over the spot where the plant will sit. NC State Extension describes what the shadow tells you:

A crisp, sharp shadow means direct sun.
A fuzzy, soft shadow means bright indirect light.
A faint shadow means low light.

The RHS uses the same idea: bright light that doesn’t cast a sharply defined shadow is generally fine for most houseplants in summer.

Repeat the test in different seasons. Winter sun is weaker and comes in at a different angle, so the same spot can be a very different place in December than in June.

Measuring With a Light Meter or Phone App

The Missouri Botanical Garden calls a light meter the best way to find out how much light a window location gets. UF/IFAS recommends a hand-held digital light meter and mentions phone apps as a way to get an approximation.

How to measure:

Take readings around midday, on both sunny and cloudy days.
Hold the sensor at leaf height, facing the light source (the window).
Measure several spots in the room and compare them. You’ll see how fast light drops off.
Compare your readings with the table above.

How far can you trust a phone? A University of Maribor study (Vujica Herzog et al., 2022) compared Android and iOS phones against a professional lux meter. The authors concluded that phones aren’t reliable for high-precision measurements without proper calibration, but that most give good, meaningful data for home use, photography, or plant growing. Use your phone to compare spots, not to chase an exact number.

Signs Your Plant Gets the Wrong Light

Too little light (University of Maryland Extension, Missouri Botanical Garden, NC State Extension):

Leggy, stretched growth with long gaps between leaves
Leaning toward the window
Smaller, paler new leaves
Slow or no growth, no flowers
Variegated leaves turning green. NC State Extension notes this for pothos. More in our guide to variegation reversion.

Too much light (Clemson HGIC, University of Maryland Extension, RHS):

Leaves bleach, turn brown, or die back
Scorched patches, usually on the side facing the window
Dull-looking foliage on shade-loving plants

The RHS warns that strong summer sun can scorch susceptible plants through glass, while in winter, when daylight is weak, full sun helps them. University of Maryland Extension suggests a sheer curtain to soften direct summer sun.

Make Changes Gradually

Clemson HGIC advises that any change in light intensity should be gradual. Don’t move a plant from a dim corner straight onto a south windowsill. Step it closer over a few weeks, or you risk scorched leaves.

The reverse matters too: a plant moved into dimmer light uses less water. After a move, water by checking the soil, not by habit.

Adding Artificial Light

If daylight isn’t enough, supplemental lighting helps. UF/IFAS recommends fluorescent and LED lights over incandescent bulbs. Clemson HGIC says 16 hours of light and 8 hours of darkness suits most plants, and Illinois Extension advises against more than 16 hours of light a day.

What to Put Where

Low-light spots: shade-tolerant plants. See our list of low-light houseplants, such as ZZ plant and snake plant.
Bright indirect light: most aroids, including monstera, pothos, and heartleaf philodendron.
Direct sun: cacti and succulents. Most tropical foliage plants won’t tolerate hot summer sun through glass.