Pet-safe plants for low light

A plant for a dim room in a home with a cat or dog has to pass two tests. The ASPCA has to list it as non-toxic to both cats and dogs, and extension services have to agree it copes with low light. Of the 74 plants in our database, 15 pass both. They are in the table below.

Plenty of plants sold as “low light” fail the first test. Before you buy, it helps to know what low light means and which popular picks are toxic.

What “low light” actually means

Your eyes are a poor light meter. UF/IFAS explains that eyes adjust so well that a desk by a window can be ten times brighter than a workspace across the hall, yet both look “bright” after a few minutes. Here is how extension services put numbers on it:

• UF/IFAS: low light is 25-100 foot-candles at midday (about 270-1,080 lux). These are spots with very little natural light, often far from windows or lit only by ceiling lights. A room lit only by fluorescent bulbs is often 40 fc or less.
• University of Maryland: low light is 25-100 fc, typical of north-facing windows or rooms with only artificial light.
• Illinois Extension: low light is about 75 fc (about 800 lux). That is a few feet from a north window, 3-10 ft (0.9-3 m) from an east or west window, or 15-20 ft (4.6-6 m) from a south window.
• Iowa State: foliage houseplants rated for low light need a daily light integral (DLI) of 3-6 mol/m²/day.

DLI is the total light a spot gets over a whole day. It is what our Window Light Planner uses. A steady 75 fc for 10 hours works out to only about 0.5 mol/m²/day (using Apogee’s sunlight factor of 0.0185 µmol/m²/s per lux). So the planner treats 3 mol/m²/day as the level where a low-light plant keeps growing, and Illinois’s 75 fc as the minimum it survives on. The light converter does the same conversion for a reading from your own meter.

Why low-light plants still need a window

“Tolerates low light” means a plant survives there. It does not mean it thrives. Maryland Extension notes that light falls off quickly as you move away from the source. Plants that get too little become leggy, lean toward the window, fade and grow poorly.

Here are estimates from our planner for a north window in New York City (latitude 40.7° N). We assumed a standard 3 x 4 ft window with clear double glazing, open sky outside and mixed weather:

• 1 ft (0.3 m) from the glass: about 2.7 mol/m²/day in December, rising to 8.3 in June
• 3 ft (0.9 m): about 1.3 to 4.1
• 5 ft (1.5 m): about 0.7 to 2.2
• 10 ft (3 m): about 0.3 to 0.8

Right at the glass, a low-light plant reaches its growth level for most of the year and dips only in December and January. At 10 ft it falls below the survival minimum in some months, and the planner rates it “too dim”. Several plants in the table have their own warning signs of too little light. Spider plant grows more slowly and loses variegation. Zebra haworthia stretches and loses color. Parlor palm gets yellow leaves and weak growth.

Choosing from the table

The 15 plants differ more than the “low light” label suggests:

• Truly shade-loving: cast iron plant prefers shade and cannot take direct sun. That makes it one of the best choices for dim rooms and offices.
• Palms: parlor palm, kentia palm and lady palm all tolerate low light, but each grows best in bright, indirect light.
• Small tabletop plants: baby rubber plant and ripple peperomia can handle low light for several months. Ripple peperomia also does well under office fluorescent lights. Aluminum plant, baby’s tears and zebra haworthia also tolerate lower light.
• Hanging plants: spider plant copes with low light. Grape ivy tolerates a range of light down to heavy shade.
• Fussier choices: calathea and prayer plant cope with fairly low light, but our database rates them demanding because they need warmth and high humidity. Guzmania comes from shadier habitats than most bromeliads and copes with lower light, including artificial light. Money tree prefers bright, indirect light but can tolerate near-full shade.

The ASPCA warns that eating any plant material can cause vomiting and stomach upset in cats and dogs. “Non-toxic” means a plant is not expected to cause serious poisoning, so it is still worth keeping plants away from a determined chewer.

Popular low-light plants that are not pet-safe

Many plants on extension low-light lists are toxic. Illinois lists mother-in-law’s tongue (snake plant), heartleaf philodendron, Chinese evergreen and Spathiphyllum (peace lily) as low-light plants. Maryland names snake plant and peace lily. Every one of these is toxic to cats and dogs according to the ASPCA:

Plant	ASPCA: cats and dogs	Toxic principle (ASPCA)
Golden pothos	Toxic	Insoluble calcium oxalates
Heartleaf philodendron	Toxic	Insoluble calcium oxalates
Peace lily	Toxic	Insoluble calcium oxalates
Chinese evergreen	Toxic	Insoluble calcium oxalates
Dieffenbachia	Toxic	Insoluble calcium oxalates, proteolytic enzyme
Snake plant	Toxic	Saponins
Madagascar dragon tree	Toxic	Saponins
Asparagus fern	Toxic	Not named; the ASPCA lists skin irritation with repeated contact, and stomach upset if berries are eaten

The Merck Veterinary Manual explains that calcium oxalate plants contain needle-like crystals. When a pet chews the plant, the crystals irritate the mouth. Our guides on pothos and snake plants cover symptoms and pet-safe swaps.

Maryland also lists the ZZ plant as low-light. It is not in our checker yet, so look it up on the ASPCA list before you buy it.

If your pet has chewed a toxic plant, call your veterinarian or the ASPCA Animal Poison Control Center at (888) 426-4435. The line is open 24/7, and a consultation fee may apply. This guide is general information, not veterinary advice.

How to use the planner and the checker

Window Light Planner:

1. Enter your city or latitude. Pick the direction the window faces: stand inside and look out through the glass. Then set how far the plant sits from the glass.
2. Set what is outside the window, the type of glass and the window size. The weather setting fills in when you pick a city.
3. Tick “Non-toxic to cats” and “Non-toxic to dogs”. You can also limit the list to easy-care plants.
4. Read each plant’s rating. “Thrives” means it gets enough light to grow all year. “Winter dip” means it falls short for up to four months. “Survives” means it gets enough to hold on but grows slowly. “Too dim” means it drops below its survival level in some months.

If your spot comes out too dim, move the plant closer to the window. Illinois Extension also notes that plants in low light benefit from longer days under lights: 14-16 hours, never more than 16.

Pet-safe plant checker: type a common name, scientific name or nickname. The checker shows the ASPCA status for cats and dogs. For toxic plants it adds the toxic principles and clinical signs, and every result links to the ASPCA entry. Common names can be misleading. Merck points out that plants with the same common name can belong to different families and differ in toxicity, so check the scientific name on the plant tag when you can.