These sun-loving annuals are adored by so many gardeners because they produce beautiful flowers with a long bloom cycle, grow more prolifically with pinching, and root easily from cuttings.
Zinnias can be grown from seed, or stem cuttings can be used to start new plants.
A Stem Cutting is what?
Having a basic understanding of what a stem cutting is will help you determine which parts of a plant can be used for propagation.
When a new plant grows from a stem cutting, it has been specifically chosen to root and develop. When we propagate a plant in this manner, we are merely taking an existing piece of the plant (a “clone”) and growing it separately. This is known as “vegetative” rather than “sexual” reproduction. There is no need for flowering or pollination.
Zinnias have a single stem, or multiple stems if they’re in a pot. The stems of young plants may have a hairy appearance. Normal behavior.
The opposite-growing leaves are also “sessile,” meaning they attach directly to the stems, without their own stalks or peduncles, as you can see in the photo.
In zinnias, the area of the stem where the leaves are located is capable of forming roots as well.
Zinnia Cutting Techniques
Taking cuttings from zinnias can be tricky
Cutting at any time is fine, but younger cuttings tend to perform better. You also want to give the cutting time to develop, bud, and bloom before the cold weather arrives.
When pinching back zinnias, many gardeners take cuttings for rooting.
It’s best to wait until your plant has at least 8 to 12 inches of stem with several sets of leaves before taking cuttings, but it should not yet be budding or flowering.
Geranium (Pelargonium) and viburnum softwood cuttings can be taken using a similar technique.
Steps
Select a stem with a variety of leaf sets to choose from.
This is where you’ll make your cut: the “tip” of the stem and the base of the stem.
We’ll use a stem with three sets of leaves as an example.
Make a diagonal cut at the base of the plant’s stem, just below the lowest leaf set, to remove the plant’s stem.
Remove the last few leaves from the base of the plant.
Submerge the bottom two inches of the stem in warm water. There should be no leaves floating in the water.
Avoid direct sunlight and store at 75°F (24°C) or higher.
Every day or two, swap out the water.
Within a week to ten days, you should see the first signs of a root system.
ZINNIA CUTTINGS CAN BE PLANTED
Keep the top of the roots at least a half-inch below the surface of the soil.
You have the option of planting your rooted cuttings in the ground or in a container.
Give the zinnias time to adjust if the new location is much sunnier than when the cuttings were rooted, because they can react to large changes.
You can do this by gradually exposing them to the new location over the next week or so.
Taking Roots in the Earth
In a well-drained, full-sun location, plant your rooted cuttings.
Keep the soil moist to encourage root growth.
Using Containers for Gardening
If you prefer, you can grow the cuttings in a pot and then transplant them into the ground at a later date.
Avoid replanting zinnias as much as possible, as they can be fussy about change.
Can I grow zinnias in my house?
Indoors, zinnias struggle mightily. The summer months may be ideal for keeping them happy in a bright window, but most gardeners agree that they thrive better in the open air.
However, you can get some short-term blooms inside.
As the stem was just beginning to form buds, I took this cutting. When I placed the cutting in a sunny window for two weeks, I was rewarded with this tiny flower. An indoor bloom from the same plant is about a third of the size.
A window sill filled with jars of these tiny blooms would look lovely.
