Don Kinzler, Published March 21 2014
Growing Together: Houseplant cuttings a bucket full of fun
As a young boy when I heard my grandmother say she was going to give Aunt Margaret the slip, I thought they were playing hide-and-seek. But “slip” is an old term for cuttings, which were often simply rooted in a glass of water.
I still use the water method for a few easy-to-root types like coleus. But new roots often develop more slowly in water because of its lower oxygen content. Roots formed in water may suffer culture shock when transplanted into potting soil.
Spring is a great time to start new houseplants because plants sense the longer day length. Increased light levels trigger new energetic growth.
Forty years ago I learned a method in horticulture lab that I’ve used ever since when rooting houseplants. The “ice cream bucket method” creates a miniature greenhouse that keeps cuttings cozy and humid until they root. It’s also a great project to encourage children’s interest in plants.
The type of cutting depends on the type of plant. Houseplants with leaves spaced along stems are rooted from “stem cuttings.” Examples are ivies, pothos, impatiens, coleus and arrowhead plant. With a sharp knife or shears, cut a four- to six-inch section of stem from the tips of the plant and remove leaves from the lower 1 or 2 inches.
Houseplants that grow from leaves arising from a central crown rather than upright stems can be rooted from “leaf cuttings,” consisting of the leaf and its leafstalk (called the petiole). African violets are an example.
Cuttings are best taken from firm, fresh growth. Water the mother plant the day before so leaves and stems are turgid and energy-packed.
When my wife Mary saw me preparing a cutting bucket for “Growing Together,” she suggested we might need to build an addition for all the new offspring.
Ice cream bucket method
A four- or five-quart ice cream bucket or similar pail
A clear plastic bag large enough to hold the bucket
Sand, perlite, vermiculite, peat moss or combinations of these well-drained materials. Jiffy Mix, which is a blend of fine vermiculite and peat, works well and is available in bags just the right size.
1. Poke or drill six holes in the bottom of the bucket to allow excess moisture to drain.
2. Attach a wire hoop across the top of the bucket in the opposite direction of the bucket’s handle. Loop the wire around the handle so both stay upright. The added wire and the handle form an x-shaped support dome over the bucket.
3. Before adding the “media” mixture to the bucket, moisten it well and stir by hand. Then fill the bucket two-thirds full.
4. Take cuttings right before you are ready to “stick” them so they’ll be fresh, not wilted.
5. Cuttings of difficult-to-root plants may be dipped in rooting hormone powder available at garden centers. Rooting powder is not necessary for most houseplant cuttings.
6. Poke a hole in the media with a pencil. Insert the cutting and pack media firmly around it. Follow the old truism that says, “A cutting that wiggles won’t root.”
7. A bucket can hold six to 10 cuttings depending on their size. Assortments are fine, although some types root faster than others.
8. Even though you’ve pre-moistened the media, water again after all cuttings are “stuck” to level and firm the media.
8. Set the bucket in the clear plastic bag and raise the bag up over the top of the wire support. Fasten the top loosely with wire or twistem.
9. Place the little greenhouse in a window receiving some direct sunlight but not all-day full sun. Humidity and warmth will speed rooting. Open the top of the plastic a little if it seems too hot.
10. The cutting bucket doesn’t require much extra water. Keep a spray bottle handy to mist inside the bag occasionally. Water if the media begins to dry.
11. Most cuttings take two or three weeks to form roots. Literature often says to check by tugging on cuttings. I compare this to lifting a baby by its ears because tender, new roots can be easily torn. Instead insert a fork into the media and gently lift the cutting. If roots are just beginning, replant and water.
12. When roots are 1 to 2 inches long, cuttings are ready to transplant. Use quality potting mix and plant each cutting in a three- or four-inch pot. Increase pot size as the cuttings grow.
Don Kinzler, a lifelong gardener, worked as an NDSU Extension horticulturist and owned Kinzler’s Greenhouse in Fargo. Readers can reach him at firstname.lastname@example.org