September: 7 houseplants to bring indoors before the cool nights hit

Tropical houseplants that spent the summer outdoors have soaked up warmth and humidity. But in September, cool nights become a real risk: cold shock, leaf drop, and above all pests (spider mites, scale, mealybugs) that can hitch a ride indoors. Here are the species to bring in first.

Watch nighttime temperatures

There's no universal date — it depends on your growing zone. The golden rule is to track nighttime minimums rather than daytime highs. Once nights approach 50°F (10°C), many plants' roots enter survival mode. To avoid acclimation shock, ease the transition over 7 to 10 days: first move pots to deep shade, then bring them in at night while leaving them out on warm days.

The 7 plants to bring in early

• Fiddle leaf fig: dislikes cold and sudden changes. Bring it in well before nights consistently hit 50°F, and ease off watering.
• Bird of paradise (Strelitzia): wipe its broad leaves clean of dust, hard-water deposits and spider mites before moving day.
• Rex begonia: cold-sensitive from about 55°F; its leaves can turn translucent or drop.
• Calathea: a diva that suffers below 60°F at night. Transition over 7-10 days and water with filtered water.
• Boston fern: shake the pot and hose down the fronds to remove whiteflies and scale before bringing it in.
• Tropical hibiscus: bring it in while nights are mild, around 60°F, early in September.
• Anthurium: growth halts below 60°F at night. Wipe leaves to dislodge aphids and scale.

A mandatory pest inspection

Before any pot crosses your threshold, hose down foliage, treat the soil with an organic neem drench and inspect the undersides of leaves. It's the best way to avoid importing pests into your home. Then place each plant where it thrives: sun-lovers near bright windows, delicate foliage in more humid, shaded spots.

Source

• Gardening Know How — 7 Houseplants You Should Bring Inside in September