Pothos plants are a popular choice for indoor greenery, admired for their trailing vines and attractive foliage. Small, brown bumps often form along their stems, which can be a natural part of growth or signal an underlying issue. Understanding this distinction is important for maintaining a healthy plant.
Normal Brown Bumps: Aerial Roots
The most common brown bumps on Pothos stems are aerial roots, a natural adaptation for this vining plant. These roots emerge from the nodes along the stem, where leaves and new growth originate. Aerial roots help Pothos cling to surfaces like trees for support as it climbs in its natural habitat. Even indoors, the plant retains this ability.
These roots also absorb moisture and nutrients from the air, contributing to the plant’s overall vigor. Their presence often indicates a healthy, actively growing plant. Pothos aerial roots are useful for propagation, as cuttings with visible nodes easily root in water or soil to create new plants.
Problematic Brown Bumps: Identifying Issues
While many brown bumps are aerial roots, some indicate pests, specifically scale insects. Scale insects appear as small, circular or oval bumps that attach to the plant’s stems and leaves. They often have a shell-like appearance and can be hard or soft, sometimes blending with the plant’s natural coloration. These sap-sucking insects feed on the plant’s fluids, leading to various signs of distress.
An infestation might also be noticeable by a sticky residue, known as honeydew, on the leaves or surfaces below the plant. This sticky substance can lead to black sooty mold. Other indicators of scale include yellowing leaves, stunted growth, or a general decline in plant health. To confirm if a bump is a scale insect, gently scrape it off with a fingernail or soft tool; scale insects will typically come off, leaving a small mark.
Treating Problematic Bumps
Treating problematic brown bumps, primarily scale insects, involves consistent and thorough treatment. For minor infestations, manual removal is an effective first step. Gently scrape insects off the plant using your fingernail, a soft cloth, or a cotton swab dipped in rubbing alcohol. The alcohol helps dissolve their protective waxy coating and dehydrate the insects.
For more widespread infestations, horticultural oils or insecticidal soaps can be applied. Horticultural oils work by suffocating insects, while insecticidal soaps disrupt their cell membranes. Ensure complete coverage of the plant, including undersides of leaves and stem crevices, as scale insects can hide in various spots. Repeat treatments are often necessary every few days or weeks until the infestation is controlled, as new crawlers (young scale insects) may hatch. In severe cases, pruning heavily infested stems can reduce the overall pest population.
Preventing Future Issues
Preventing problematic brown bumps, particularly scale infestations, involves maintaining optimal growing conditions and regular vigilance. Proper watering is important; allow the top inch or two of soil to dry out between waterings to prevent overly moist conditions that can attract pests. Well-draining soil also prevents root issues that weaken the plant and make it more susceptible to pests.
Adequate light, typically bright, indirect sunlight, promotes a strong, healthy plant less vulnerable to infestations. Balanced humidity levels are also beneficial for their overall health. Regularly inspecting your Pothos, especially new plants, helps in early detection. Wiping down leaves periodically also removes dust and nascent pest populations.