What to Do With Your Peace Lily in September to Keep It Green, Healthy and Blooming

September is a transition month for peace lilies across the United States. In some parts of the country, summer heat is still going strong; elsewhere, cooler nights are already signaling the arrival of fall. Indoors, changes in daylight, air conditioning and eventually home heating can all affect how your peace lily grows.

I have the Peace Lily Plant from Trees.com (formerly Fast-Growing Trees) in my own home, and September is a good reminder that even an easy-care houseplant benefits from a few seasonal adjustments. Understanding the basics of peace lily care can help keep the plant healthy as it moves from summer into fall, whether it spends the warmer months on a shaded porch or grows indoors year-round.

1. Move Your Peace Lily to the Right Light

As the days grow shorter, your peace lily may need a brighter spot than it did in the height of summer. When deciding where to place a peace lily, look for bright, indirect light near an east- or north-facing window. A few feet from a bright south- or west-facing window can also work, provided the plant is protected from intense direct afternoon sun.

If you've kept your peace lily outdoors for the summer, don't put it straight into full sun. Peace lilies prefer filtered or dappled light, and sudden exposure to strong sunlight can scorch their leaves. A plant stand can also help you position your peace lily at the right height and move it closer to a brighter window as the seasons change. The IKEA OLIVBLAD plant stand is one practical option; its tiered design makes it easy to display plants at different heights.

2. Bring Outdoor Peace Lilies Inside

For gardeners who move houseplants outdoors during the warmer months, September is an important month to start planning the move indoors. The timing depends heavily on where you live. In northern states and higher elevations, cool nights may arrive early. In warmer parts of the South and Southwest, outdoor conditions may remain suitable much longer.

Before bringing a peace lily indoors, check the leaves, stems and soil for insects. Look underneath leaves for pests or webbing, and remove any dead or damaged foliage. Rinse the plant gently if necessary. If you're looking for a peace lily to add to your indoor collection, the Costa Farms Spathiphyllum Peace Lily from The Home Depot is one option.

Keep the plant separate from other houseplants for several days if you've had pest problems. If you find insects or mites, a product such as BioAdvanced Houseplant Insect & Mite Control from Amazon can help address common pest problems when used as directed.

3. Adjust Watering as Winter Approaches

Don't automatically continue your summer watering schedule throughout September. If temperatures are falling and daylight is decreasing, your peace lily may use water more slowly. On the other hand, a plant in a warm, air-conditioned home may still dry out quickly. If you're wondering how to water a peace lily, the best approach is to check the potting mix rather than watering on a fixed schedule.

A simple XLUX Soil Moisture Meter from Amazon can help you check moisture levels below the surface, while a Haws Indoor Plastic Watering Can makes it easier to water slowly and evenly when the plant needs a drink. When the upper portion of the potting mix feels slightly dry, water thoroughly and allow excess water to drain from the pot. Avoid allowing the plant to sit in a saucer of standing water. Consistently soggy soil can contribute to root problems.

4. Start Preparing for Indoor Heating

In northern states and colder regions, September is also the time to think ahead to the heating season. Forced-air heating can make indoor air considerably drier, which may cause peace lily leaves to develop brown edges or tips. Before the furnace starts running regularly, consider moving the plant away from heat vents, fireplaces and radiators.

A Levoit Classic 300S Ultrasonic Humidifier from Amazon can help add moisture to the air and maintain a more comfortable environment for tropical houseplants during the dry winter months.

5. Ease Back on Fertilizer

A peace lily that's actively producing new leaves or flowers may still benefit from fertilizer in early September. If you're looking for a peace lily fertilizer, choose a balanced, water-soluble formula and follow the product label rather than automatically increasing the amount. Options such as Miracle-Gro Indoor Plant Food or Espoma Organic Indoor! Plant Food from Amazon can be convenient choices for feeding houseplants.

As growth slows later in fall, however, there's usually less need to fertilize frequently. Continuing heavy feeding when the plant isn't actively growing can result in excess salts accumulating in the potting mix. Follow the fertilizer label and reduce feeding as the plant's growth naturally slows. A healthy peace lily doesn't need to be pushed into constant growth.

6. Clean Those Big Leaves

September is an excellent time to give your peace lily a foliage makeover. Its broad leaves collect dust, pollen and other debris, especially after spending the summer near an open window or outdoors. Wipe the leaves gently with a clean, damp cloth.

A microfiber cleaning cloth from Amazon works well for lifting dust without being rough on the foliage, while an amber glass plant mister can be useful for lightly dampening leaves before wiping them clean. This removes accumulated dust and gives the plant a fresher appearance as you bring it indoors for fall. Skip leaf-shine products, which aren't necessary and can leave unwanted residue on the foliage.

7. Check for Common Houseplant Pests

Before moving an outdoor peace lily inside, inspect it carefully for pests. Look for:

• Spider mites and fine webbing
• Mealybugs that resemble small white cottony spots
• Scale insects attached to stems or leaves
• Fungus gnats around damp potting soil
• Sticky residue or unexplained leaf damage
• Finding pests before the plant joins your indoor collection can save you a much bigger problem later

8. Prune Yellow or Damaged Leaves

September is a good time to tidy your peace lily before it settles into its fall growing routine. If you're wondering how to prune a peace lily, start by removing completely yellow, brown or badly damaged leaves with clean, sharp scissors. Fiskars Micro-Tip Pruning Snips from Amazon are useful for making precise cuts around stems and foliage, while Fiskars Steel Bypass Pruning Shears from The Home Depot are another option for thicker stems.

Cut the leaf stem near its base rather than simply trimming the damaged portion. You can also remove spent flowers once they have faded. This keeps the plant looking neat and can encourage it to focus on healthy foliage and new growth.

As summer comes to a close, help your peace lily transition smoothly into fall. Adjust watering as daylight decreases, provide bright, indirect light, and protect the plant from cold drafts and extreme temperatures.

If your peace lily spent the summer outdoors, inspect it for pests and bring it inside before chilly weather arrives. Keep it away from heating and cooling vents, clean dusty leaves, watch for pests, and reduce fertilizer as growth slows. If the plant is root-bound, this is also a good time to repot a peace lily before fall growth slows.

A little seasonal care now can help keep your peace lily healthy, lush and vibrant through the cooler months.