How to keep dormant plants alive, transplant hellebores and tend houseplants during winter
The end of December is time to check your overwintering plants to see if they need just a bit of water. You know, those geraniums stored in the garage, the dahlia tubers tucked away, and abutilon shoved under the eaves of the house.
The goal is to give these dormant plants and tubers just enough moisture to keep them alive but not enough so that they wake from winter hibernation and think it is spring. Depending on the size of pot or type of growing or storage medium, just a few tablespoons to up to a half a cup of water should be enough. Think sips to drink, not gallons to guzzle.
Q. I was given a hellebore as a gift. It has been sitting indoors with a red foil wrapper around the plastic pot. When should I move this plant outdoors? Also, when do I plant it into the ground? — G.H., Olympia
A. Time to get a move on now.
First, set the potted hellebore outdoors on a covered porch or patio for a few nights. This will harden it up for the real move into the cold cruel outdoor world.
Wait for mild winter weather then dig a wide, deep hole for your new hellebore. Hellebores hate to be transplanted as they have fleshy roots that break easily. The wider the planting hole, the less likely you will damage the brittle hellebore roots. For a one gallon pot, a hole 2 feet wide should be good.
Add some organic matter such as leaf mold to the planting hole and then mulch the top of your newly planted hellebore with rotted leaves or bark chips. A good drink after the transplant operation will help the soil to settle in around the roots and welcome this new perennial to your garden.
Q. My orchid is done blooming. Should I cut off the flowering stem? — T., Email
A. Yes, you can get snippy with any faded flower, but some orchids have a flowering stem attached to another main stem that could bloom again. You did not mention what type of orchid you have, so I suggest you prune back the stem that held the flowers by one half. Let your orchid plant rest with little water and no fertilizer for a few months. It might just surprise you with a new shoot of blooms.
In our Western Washington winter climate orchids do best near a bright window.
Q. I have brown bumps on my pathos houseplant. I have figured out it is scale. I do not want to spray poison inside my house. What is your trick to removing scale from houseplants? — H.T., Enumclaw
A. Your houseplant medicine chest needs cotton swabs and rubbing alcohol.
First, dip the cotton swab into the alcohol, then touch the scaly covering on each insect clinging to your plant. After a few days, take the plant to the sink and give it a bath with a mild soap such as Ivory and a rinse with water.
Now wait a few weeks, because eggs from the first generation of scale insects may have escaped the treatment. Repeat if you see more bumps.
It is possible to eradicate scale on indoor plants if you are persistent with treatment. Or you can just toss the infested houseplant into an outdoor compost (the scale insects will freeze and die) and treat yourself to a shopping trip at a local greenhouse. New houseplants are waiting for winter adoption.
Marianne Binetti has a degree in horticulture from Washington State University and is the author of several books. Reach her at binettigarden.com.
This story was originally published December 21, 2024 at 5:00 AM with the headline "How to keep dormant plants alive, transplant hellebores and tend houseplants during winter."