Too little light
Long, weak stems with big gaps between the leaves, growing towards the window. New leaves stay small and pale, lower leaves yellow and drop, and flowering plants don’t flower.
The plant is too far from the window or in too dark a spot, especially in winter, or seedlings are on a windowsill that is too dark.
What can you do?
- Move the plant closer to the window; a metre away from the glass it already gets much less light.
- Turn the pot a quarter turn every week so the plant grows straight.
- In winter, use a grow light, especially for seedlings and light-loving plants.
- Cut back stretched stems once the plant gets more light so it regrows more compactly.
Prevention
Choose a plant that suits the light you have, and don’t sow too early in the year if you have no bright spot.