The clearest signs that a houseplant is not getting enough light are leggy or stretched growth with long gaps between leaves, new leaves that are smaller and paler than normal for the species, very slow or no new growth during the spring and summer months.
In variegated plants, new growth is predominantly green rather than variegated is a telltale sign that your plant is not getting enough light. The plant will not usually show dramatic immediate distress from insufficient light (the way it would from drought or rot) instead, light deficiency produces a gradual, progressive decline in growth quality and pace. See our guide on why variegated plants turn green.
Recognising these signs early allows you to relocate the plant or add supplemental lighting before the plant deteriorates significantly.
Leggy, Stretched Growth
When a plant does not have enough light for its growth rate, it stretches its stems toward the nearest light source in an attempt to find more. The result is long internodal gaps (wide spaces between successive leaves on the same stem), thin stems, and a sparse, stretched appearance. This is called etiolation. An Epipremnum that is growing close to a window might produce a new leaf every 5 to 7cm of stem; the same plant in low light might produce one leaf every 20 to 30cm.
Small, Pale New Leaves
Leaves produced in insufficient light are smaller than the plant's normal leaf size and paler in colour. The plant cannot produce large, fully-developed leaves with limited energy, and it increases chlorophyll density in the smaller leaves in an attempt to capture more of the limited light, making them a washed-out lighter green rather than the rich, deep green of well-lit growth. In species where leaf size and colouration are key features (dark Hoyas, large Monsteras, deep-green Philodendrons), the contrast between well-lit and poorly-lit growth is striking.
No Growth During the Growing Season
If a plant produces no new leaves from March through September, when conditions should support active growth, insufficient light is the most likely cause after overwatering and root rot have been ruled out. Some plants are genuinely very slow growers. For example, a Snake Plant (Sansevieria) producing two new leaves per growing season is normal, while a Pothos producing no new growth for four months in summer is not. It is best to read up the usual growth rates for your specific houseplants.
How to Fix Insufficient Light
The first step is moving the plant closer to a window. A position within 1 to 1.5 metres of an east, west, or south-facing window provides bright indirect light for most tropical species. The improvement from a better position is typically visible in the quality of new leaves within two to four weeks.
Where better window placement is not possible, supplemental lighting is the most reliable solution. Our grow light collection, including the GrowGang Pianta V2 and Mars Hydro TS600, provides full-spectrum light equivalent to bright indirect daylight regardless of room or season. See our guide on grow lights for houseplants for sizing and use guidance.