By: Gary Garner Sr.
A couple of months back I pinned some tips on bringing your houseplants inside for the cooler months of the year. Those tips included proper placement according to plant light needs, air circulation, plant temperature needs, indoor watering and fertilization among other things.
Now that the plants have been inside for a few weeks, if you are like me, you are beginning to see some problems with some of your plants. Most problems seem to show up in the form of yellowing leaves. Yellowing leaves may or may not indicate a problem with the plant.
Yellow leaves at the bottom of the plant may be as simple as age. Most plants lose their leaves within a year. If its bottom leaves that are yellow and falling off, I would not worry about it. If the rest of the plant is green and healthy looking, I would keep on with my normal cultural habits.
Leaves that are yellow or have yellow patches on the window side are likely sunburnt. A quick cure is to turn the plant or move it to a slightly less bright location.
Lower yellow leaves can also be caused by overwatering. Check the soil in the pot to see if its squishy wet or soggy. Overwatering is the number one cause of houseplant death. Trying to water on a set schedule is almost sure to result in plant trouble or death. Size of pot, type of plant, air circulation and room temperature all help to determine how often to water. It is something that must be learned.
Yellowing of lower leaves can also be caused by under watering. That can also be determined simply by feeling and poking your finger in the soil. As I have written repeatedly, your finger is the best water meter you will ever have.
A lot of yellow lower leaves or pale green leaves throughout the plant may be a sign of a lack of nitrogen. This might well be an indication that the plant needs repotting. Not necessarily to a larger pot but just some richer fresh potting soil. Drainage of water through the soil in the pot depletes the nutrients in the soil. An application of houseplant fertilizer might help or cure the problem. I would add that plants are best fertilized during periods of active growth and not when the plant is resting.
Upper yellow leaves may indicate a sign of lime intolerance or chlorosis. If your water source is high in lime or calcium, then you should consider collecting rainwater to use for watering your plants. Frequently, the new leaves on acid loving plants, indoor or outdoor, are light green with dark veins, another indicator of chlorosis. Lime keeps them from absorbing the iron needed for photosynthesis. This can be prevented by using a chelated iron fertilizer formulated for acid loving houseplants.
Yellow leaves are not going to green back up. Once they yellow, regardless of the cause, they will typically fall off if you haven’t already pruned them off. Then we must wait and see what the new growth looks like.
As I often say gardening is a learning process. We all make mistakes no matter how long we have been growing. Hopefully we all learn something new daily.