Allen Wilson is a Vancouver gardening specialist. Email Allen Wilson at [email protected]
My indoor plants seem to be under stress. I am noticing more brown and yellow leaves and leaf tips. I see very little new leaf growth. What can I do to perk them up?
We are approaching the lowest winter light conditions of the year with the winter solstice coming Dec. 21. Plants almost stop growing or actually lose more leaves than they replace. As long as they are producing new leaves, there is not a lot to be worried about. There are a few things which can help.
Light is a key ingredient for plant growth. Make sure plants are getting the maximum light available.
Leaves accumulate dust, which reduces light. Shiny leaf plants can be wiped with a damp cloth. Fuzzy leaf plants like African violet do not like moisture on their leaves but they can be dusted with a feather duster. Make sure your shades are open near plants. Plants can be moved closer to windows, especially south facing windows. Plants can also be placed under lamps that are left on during evening hours.
Avoid overwatering and overfertilizing. Our tendency is to water plants on a regular schedule, such as once a week. Slower plant growth means less water and fertilizer are used by the roots. When soil stays too wet, oxygen is more limited for the roots which limits root growth. Reduced root growth leads to reduced leaf growth. Check to make sure the soil is dry on top before watering. Reduce fertilizer by half to match the slower growth rate. Instead of liquid fertilizer I like to use Osmocote coated fertilizer which only needs to be applied about once every three months. Water seeps through the coating and dissolves a little fertilizer inside the coating each time a plant is watered. Less watering means less fertilizer.
Brown leaf tips can be trimmed with scissors. Trim so you keep the same leaf shape. Plants naturally transfer nitrogen from older leaves to new ones. That is why the older leaves become yellow. When a leaf becomes more than half brown or yellow, it is time to remove it.
You might want to consider replacing higher-light requiring plants with those needing less light. Check an indoor plant book that gives light requirements or search on line for “low-light house plants.” Indoor plants that tolerate the lowest light conditions include Chinese evergreen, cast iron plant, peace lily and snake plant. Also low-light tolerant are dieffenbachia, dracaena, parlor palm and devil’s ivy.