Heirloom Expert: Should You Fertilize House Plants?

If you have a house plant, should you add fertilizer to them? Doug Oster has the answer.

By Doug Oster


Spring 2016

Houseplants

"Most houseplants are killed with kindness; too much water and too much fertilizer."

Photo by Fotolia/imnoom

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I read one of your earlier columns about growing poinsettias inside and kept two going after the holiday. They look great, even though they have lost their color. I’ve got several other plants growing on the windowsill and wondered if they should be fertilized.

Great job keeping those poinsettias going! It’s a good thing you haven’t been fertilizing. In the winter there isn’t enough light for the plants to be able to use the fertilizer. Now as the days are getting longer, its fine to give the plants a little help; just don’t overdo it. Most houseplants are killed with kindness; too much water and too much fertilizer. 

Use a good, organic liquid fertilizer mixed at half strength once a month over the summer. Those poinsettias, though, can be planted in the garden after chance of frost has passed. It’s fun to keep them going from year to year. They’ll color up a little bit when the light is right and can go back on the windowsill before the first frost of the fall hits.

Doug Oster, contributing editor