How to Grow and Care for Hypoestes (Polka Dot) Plants
The polka dot plant (Hypoestes phyllostachya) is an eye-catching little plant with brightly variegated leaves that stand out against most other foliage. The most common polka dot plants feature leaves with a pink base color and green spots. But there are several spotted or mottled varieties with purple, white, red, and deeper colors and brighter contrast, so the plants pop even more. These plants are not especially difficult to grow, but because they are native to warm climates, many gardeners treat them as annuals and replace them with new plants each year. They're best planted in the spring. They also can be grown in containers as houseplants. They have a moderate growth rate and remain relatively small once mature, especially when grown indoors. They are not considered invasive plants; however, they have a vigorous growth rate in Australia, where they are a weed and have become invasive..
Polka Dot Plant Care
Warm temperatures and humidity are key to growing polka dot plants. Expect to water regularly unless you get sufficient rainfall. This plant also needs regular feeding throughout the spring to fall growing season.
Polka dot plants bloom sporadically, typically during the summer, with small lilac or pink-colored flowers on spikes. Pinch off these flower spikes to keep the plant’s energy focused on growing its vibrant foliage.
When grown outdoors, polka dot plants like a spot with some shade. Pick a planting site that's not in low light or too much light or else you can expect the foliage colors to fade, lessening the plant's ornamental value. Bright, indirect light is ideal indoors, such as from an east- or south-facing window.
Polka dot plants prefer organically rich soil with good drainage. An all-purpose organic potting mix is typically suitable for these plants. Mix in some pumice or perlite to improve soil drainage.
These plants like a moderate amount of moisture in the soil at all times. Avoid letting the soil completely dry out, which can cause the foliage to wilt and make the plant struggle to survive. Never let the soil become soggy, which can cause root rot and kill the plant. Water the plant when the top half-inch of soil has dried out. Give enough water to moisten the soil evenly. You will need to water container plants more frequently than in-ground plants. Slightly reduce watering in the winter and resume your routine once growth picks up again in the spring.
Temperature and Humidity
Polka dot plants are only hardy in USDA growing zones 10 and 11, preferring temperatures over 60 degrees F. They should be planted outside in the spring after the threat of frost has passed and brought inside if you plan to overwinter them well before the first frost of the fall. These plants like humid conditions, preferring a minimum humidity level of 50 percent. If you need to raise the humidity, you can mist your plant’s leaves or place its pot on a tray filled with pebbles and water as long as the bottom of the pot isn’t touching the water.
Feed container plants with an organic fertilizer designed for houseplants once a month during the warm growing season. These plants are heavy feeders. If planting in-ground, mix a layer of compost into the soil each spring.
Polka dot plants tend to get leggy. You’ll need a pair of clean, sharp scissors or pruning shears to keep the plant from developing long, lanky branches. To promote a bushier growth habit, cut or pinch back the top two leaves on each stem weekly. Actively trimming can help the plant to grow healthier and more vigorously. Although flowers sound nice, it's best to clip them when they start appearing to extend the growing season of your polka dot plant. The flowers aren't as ornamental as the leaves anyway. The plant will die off or enter dormancy once it has finished flowering.
Polka dot plants can be grown from seeds or stem cuttings. If you are starting from seeds, sow them in the early spring. You can propagate from cuttings anytime; however, your success rate of growing a healthy plant will be best in the spring or summer. Trimming your polka dot plant is a good way to maintain a bushier, healthier plant. If you live in a non-tropical climate, your polka dot plants will die once the first frost comes. If you notice your plant is dying outdoors, stem cutting is a great way to revive your plant indoors.
Common Pests and Diseases
Common pests that enjoy polka dot plants are mealybugs, aphids, and whiteflies. Typical diseases associated with polka dot plants are root rot, leaf-spot diseases, and powdery mildew.2 Telltale signs of these bug infestations or disease include foliage that's discolored, leaves that have holes or otherwise appear unhealthy, and small bugs moving on the plants.