Learn how to propagate bleeding hearts
Question: I have a bleeding heart that was given to me by my mother-in-law. My daughter would like to have a piece of the plant, but I’m not sure how to divide it since it has died back for the season. What is the best time to divide a bleeding heart and how should I go about doing it?
Answer: Old-fashioned bleeding hearts (Lamprocapnos spectabilis, syn. Dicentra spectabilis) are lovely plants. I understand why your daughter would like to have a piece of the one that belonged to her grandmother. Thankfully there are several ways you can propagate this popular perennial.
First, bleeding hearts are easy to divide through classic crown division. For bleeding hearts, there are a few different times you can complete this process. The first is in the very early spring, when the plant is just beginning to peek through the soil. The biggest negative of this timing is that sometimes the young shoots can break off during the process, affecting its growth and flower production for the season.
Another option is to divide the plants when they start to die back in late summer. Bleeding hearts’ foliage turns yellow in July or August, signaling the start of dormancy. The main benefit of dividing the plant at this time is that it won’t matter if you accidentally break off a stem; they were soon to die back anyway. You’ll also have to work hard to make sure the plant stays well watered through the rest of the fall, even after it’s fully died back.
You can also divide the plant in the late fall, after it is completely dormant, but it can be hard to find the crown of the plant when nothing is visible above ground.
To divide the crown of the plant, dig up the entire root system, remove any excess soil and use a sharp knife to cut the plant in half, making sure each half has a portion of the crown attached. Immediately replant or pot up each division and water it in well.
While you have the plant out of the soil (or instead of digging up the entire plant to divide the crown), you can also take a few root cuttings to start new plants.
Growing new plants from root cuttings is a fun way to expand your garden, and spring and early fall are great times to do it. Root cuttings are a fast and easy way to make more plants, and you can do it with lots of different perennials and shrubs (including poppies, hollyhocks, phlox, Heliopsis, viburnums, hollies, hydrangeas and more).
To start new plants from root cuttings, you’ll need just a few things: A mother plant, a shovel, a clean sharp knife, some new plastic pots or a seeding flat, a bag of high-quality soil-less planting mix and water.
Begin the process by digging up the mother plant. Then, using a clean, sharp knife, remove several 2-inch long root sections; ideally each should be about as thick as a pencil.
To plant the root cuttings, fill a clean pot or seedling flat with the planting mix, and place the cuttings into the soil with the up end pointed up and the down end pointed down (maintaining polarity). If the cutting is planted upside down, it will not grow.
The top of the root piece should be about an inch below the soil’s surface. If you aren’t sure which end is up, lay the cuttings horizontally about an inch deep. Water the soil well and keep it constantly moist but never soggy. New shoots will emerge in a few weeks to a month or two depending on the plant species.
If you take root cuttings of your bleeding heart in the fall, you’ll need to overwinter the pots in a greenhouse or in a cool, but protected site (you can always sink the pots into the compost pile or a corner of the vegetable garden up to their top rim).
If you take root cuttings in the spring, the new bleeding heart sprouts can be planted into the garden later that season.
One final way to propagate your bleeding heart is to harvest and plant some of the seeds. Bleeding hearts often naturally reseed, with young plants popping up near the mother plant in the early spring. You can also harvest a few of the seed pods in the fall, let them dry completely, pack a few seeds into an envelope and put it in the fridge for the winter. Come spring, sow the seeds in seed-starting mix in a sunny window or under grow lights. It won’t take long for them to germinate, but remember to keep the seeds in the fridge to mimic the passage of winter and break seed dormancy. Growing new plants from seed is a fun process, but it will take several years for the plant to mature enough to bloom.
With these methods, you and your daughter will have plenty of bleeding hearts to remember your mother-in-law by.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden,” “Good Bug, Bad Bug,” and her newest title, “Container Gardening Complete.” Her website is jessicawalliser.com. Send your gardening or landscaping questions to [email protected] or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.