This guide is meant to teach you how to propagate Three-Lobed Spirea (Spiraea trilobata) and hopefully make it easier for you to sell them at your own nursery.
Hardiness Zone: 2 – 9
Soil Type: Well-drained sand, chalk, loam.
Exposure: Full Sun
Three-Lobed Spirea (Spiraea trilobata) is a perennial shrub hardy up to zone 2. They are a breathtaking shrub with their beautiful showy white flowers that bloom in Spring.
Three-lobe spirea’s numerous white flowers attract all sorts of pollinators.
The blueish-green foliage grows compact and dense, throughout the season and turns copper bronze during fall.
Attracts many species of butterflies along with other polinators like bees.
The flowers may also attract hummingbirds.
Best Way to Propagate Three-Lobed Spirea
Since three-lobed spirea (Spiraea trilobata) is a suckering plant, a great way to propagate it is by division.
Suckering plants naturally send out roots underground called rhizomes. These nutrient-rich rhizomes send up new clones of the plants nearby and create a colony.
- First, locate your mother plant, loot around to see new shoots.
- Once you find the shoots, use a spade and dig them out. You’ll notice a big root coming from the mother plant, that’s the rhizome.
- Take out the shoot from the ground, and cut off some of the rhizome out with it. There’s some precious energy in there.
- Prune most of the leaves from the shoot, leaving some at the top, and plant directly into a pot with soil. Voila!
Another great method to propagate three-lobed spirea is by taking cuttings. There are two harvesting seasons: hardwood and softwood cuttings season, each depends on your time of the year.
When harvesting hardwood cuttings, you want to take them early fall or early spring.
- Take some hardwood cuttings off the main stem, at about 8-10 inches long each.
- Make sure the width of the cutting is at least 1/4 inch each, thicker is just fine.
- Scrape the bark off the bottom inch of the cutting, especially at the wooden joint.
- Remove most of the leaves off the twig and leave some at the top
- Dip in rooting hormones and then push them into your sandy propagation beds.
- Keep watering the cuttings, sand shouldn’t be too wet but it should stay moist.
- Roots will form within 6-8 weeks, during winter, let the snow fall on top, it isolates the cuttings very well.
With softwood cuttings, the best time to get them is when the plant is most active, starting from late May to August.
Follow the 6 week rule: Softwood cuttings are rigid enough to harvest 6 weeks after the first leaves emerge in spring. Timing is very important.
For three-lobed spirea, softwood cuttings propagation is pretty similar to hardwood cuttings.
Snip the cuttings at about 5-6 inches long, dip the end in rooting hormone and place into propagation bed.
Softwood cuttings have a higher success rate and root faster. Under perfect conditions, they’ll be rooted and ready to transplant within 3-4 weeks.
How to Prepare Three-Lobed Spirea for Sale
Finally, once your cuttings have rooted, all you have to do is transplant them into pots with good well-draining compost or topsoil.
Three-lobed spirea can grow in all directions, prune the branches that are going in the wrong directions.
Try to keep it into a bush shape with the main stem. Snip the tallest branch to let the lower branches have a chance to get fuller. Don’t let any branch get too long.
Still trying to figure out how to start your plant nursery? Check out our plant nursery guide here.