My indoor plants are looking sickly. They are losing leaves without being replaced with new growth. Do you think fertilizer would help?
If you have not fertilized lately, it would probably help. However, the main cause of poor growth this time of year is lack of light. The lower natural light levels can have a dramatic effect on indoor plants. Plants depend upon light energy for growth. Plants can lose old leaves faster than new leaves are produced. They may also become lighter green and grow more spindly as they stretch to reach light.
Besides shorter and shorter days, two other factors further reduce natural light levels this time of year. The angle of the sun on the horizon is much lower, which can reduce light energy by two-thirds. Also, we have more cloud cover through the winter months.
Indoor plants compensate in several ways to handle the reduced light levels. They turn their leaves toward what light source is available. Leaves produce less food so their growth is slower and fewer new leaves are produced. Stems stretch longer as plants reach for available light. Older leaves mature faster, turn yellow or brown and drop at a more rapid rate. Some nutrient elements like nitrogen are recycled to younger growth.
We need to give plants as much natural light as possible by completely opening curtains and shades in the daytime. Plants that are not next to windows can be brought closer. Even plants not usually put in direct sunlight can tolerate it now. You may want to replace plants that are beyond recovery with something more tolerant of low light levels. Indoor plant books and a simple “low light tolerant indoor plants” inquiry on the internet will give you a lot of ideas.
Natural light can also be supplemented with artificial light. Plants can be placed near lamps that are allowed to remain on all night. Special plant lights with higher light intensity can also be employed.
Plant leaves accumulate dust. Leaves of many plants can be cleaned with a solution of mild detergent. Water will spot most fuzzy leaf plants such as African violets. If you are not sure whether water will damage a particular plant, clean one or two leaves and wait a couple of days to see if there are any adverse effects. Leaf shine products will also clean leaves. If plants become odd shaped because leaves are turning toward the light, rotate them a quarter-turn each week.
Morning Briefing Newsletter
Get a rundown of the latest local and regional news every Mon-Fri morning.
