Making more plants
Posted on: June 23, 2017 | Written By: Doug Oster |
Katie Werner, greenhouse production foreman at Phipps Conservatory and Botanical Garden, is snipping thin branches off a thyme plant and pushing them into 4-inch-round plastic pots filled with a soft, moist, soilless mix.
Katie Werner is production foreman at Phipps Conservatory and Botanical Gardens. She demonstrates how to take cuttings to make more plants. Photos by Doug Oster
It’s always fun to go behind the scenes into the greenhouses to explore the different techniques the experts use, in this case for making more plants.
To add to the garden, Werner says, “the first thing I think about is sowing seeds; the second thing is taking cuttings from a stock plant.”
Taking cuttings will create a clone of the plant and there are many different plants that are amenable to being propagated this way. It might seem a mysterious task, but by choosing things like impatiens, coleus, salvia, petunia, other annuals, many herbs and even some vegetables, it’s pretty easy.
“The impatiens you could just root in a glass of water,” she says.
When the roots get an inch or two long, they can be transplanted into a good grow mix. The node on the plant is critical to identify when rooting cuttings.
“The node is where the leaves come out of the stem,” Werner says. “A good rule of thumb is to always make sure you have a node either in your water or underneath the soil.”
If there are flowers, remove them so the plant will concentrate on making roots. Some growers will add a rooting hormone to the stem of an annual as a way to promote root growth.
Katie Werner, production foreman at Phipps Conservatory and Botanical Gardens, demonstrates how to take cuttings of thyme.
“We rarely use Rootone here and I rarely use it at home,” she says. “If you’re taking a cutting of a hardwood or shrub, I would use the rooting hormone as that extra little oomph.”
She enjoys taking cuttings from herbs like the thyme, oregano, basil, rosemary, sage and others.
Werner fills up the pots with a propagation mix, but a seed-starting mix from a nursery also would work as a home for the cuttings. It should be moist must not dripping wet.
“When taking cuttings you want to stay toward the softer portion of the stem,” she says.
On the thyme, Werner is working toward the top of the plant, four or five nodes down. She strips off the bottom few leaves and then sticks it into the mix. In a week or two, she’ll gently tug on the cuttings and if they resist, they have rooted. The same technique can be used for many annuals, herbs and vegetables.
Trees and shrubs are harder to root, she says.
“One thing you could try is air layering,” Werner says. A cut is made into the hardwood on a branch which is wrapped with moist sphagnum moss and then covered with plastic until the roots start to develop. Start checking the wound after a few weeks by removing the moss and plastic.
If roots have developed, cut the branch below the wound and then plant it in soil.
Rhododendrons, azaleas and some other plants are candidates for layering in the soil around the plant by using low growing branches. They naturally reproduce this way and gardeners can help the process.
The bottom of the branch is nicked and then pinned to the ground.
“You can use something like a landscape pin, something that will keep it against the soil where it will have that moisture, that’s the key point there,” Werner says.
Once the plant roots in a few months, it can be removed from the mother plant and planted in a new location.
“It’s fun because you get to multiply what you grow,” she says with a smile. “I love saving money.”
Dorothy Zenkevich takes cuttings of roses at the rose garden Renziehausen Park in McKeesport.
Dorothy Zenkevich learned to propagate roses from her cousin, Dolores Howley, who passed away last April.
“She’s the one who had me join the Rose Society,” Zenkevich says.
Once a year the Pittsburgh Rose Society (pghrosesociety.org) holds Rose Day at the Rose Garden in Renziehausen Park in McKeesport. It was Howley who would give lessons on how to take cuttings and root roses for the visitors. Now Zenkevich does the demonstration each year.
“We were more like sisters than cousins,” Zenkevich says. “We both loved gardening.”
In the shade of the front porch of the Garden Club of McKeesport’s building there are plastic bins filled with cuttings from the magnificent rose garden. Roses and hydrangeas can be propagated just about the same way, she says.
“You have to wait until the roses are in bloom, and wait for a spent bloom,” she says.
The key is cutting in the right place. The stem should be 7 to 9 inches tall. Cut one quarter of an inch above two nodes which have five leaves and then remove the spent blooms. She uses Miracle Grow potting soil mixed with vermiculite to lighten the medium for rooting.
The mix is put into an opaque plastic container with a lid. The mixture should be moist but not soaking, the lid keeps humidity up which is critical for the rooting. It’s left four to six weeks in indirect light.
“Try to pull it a little bit,” she says. “There will be a little resistance because of the roots.”
Then it can be potted and planted out in a few months.
As she thinks about her cousin, she chokes back the tears explaining why she continues to teach the techniques at the annual event. “I do it now at Rose Day because I don’t want it to be lost and I want a piece of her to remain here.”
Doug Oster is the 535mediarack.com home and garden editor. Reach him at 412-965-3278 or doster@tribweb.com or via Twitter at @dougoster1.
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