Bleeding heart plants (Lamprocapnos spectabilis) are cherished garden perennials, known for their distinctive heart-shaped flowers that dangle gracefully from arching stems. They bring a touch of elegance to shaded garden spaces. This article explores various propagation methods, offering guidance to help gardeners successfully grow more of these charming perennials.
Understanding Bleeding Heart Propagation
Gardeners often propagate bleeding hearts to increase plant numbers, share with friends, or rejuvenate older, less vigorous specimens. The timing of propagation significantly influences success rates. The most favorable times are early spring, as new growth emerges, or late summer to early fall, after the plant’s foliage dies back and it enters dormancy. Propagating during these periods aligns with the plant’s natural growth cycles, minimizing stress and promoting quicker establishment. Early spring propagation allows new divisions or cuttings to develop roots before summer heat, while late summer or early fall propagation permits root development before winter.
Propagating by Division
Division is the most common and successful method for propagating established bleeding heart plants. This process is best performed in early spring as new growth appears, or in the fall once the foliage has died back. Spring division should occur a few weeks before the last frost, while fall division is safest when the plant has entered dormancy.
To divide an established plant, carefully dig a wide circle around its crown, using a spade or garden fork to lift the entire root ball. Gently remove excess soil from the roots to expose the root mass. Look for pink-tinged root buds near the crown, as these indicate new growth points.
Using a sharp knife or spade, divide the root ball into sections. Ensure each new division has a substantial portion of roots and at least two to three growth buds. Replant each division at a similar depth to the original plant, typically one to two inches below the soil line, in amended soil.
Water the newly planted divisions thoroughly to help settle the soil around the roots. This method not only yields new plants but can also rejuvenate an older, overcrowded bleeding heart clump every few years.
Propagating by Cuttings
Propagating bleeding hearts from softwood stem cuttings offers another way to create new plants. This method is best performed from late spring to early summer, when the plant is actively growing and stems are pliable. Taking cuttings in the morning when the plant is well-hydrated can improve success.
Select healthy, non-flowering stems that are about 3 to 5 inches long. Make a clean cut just below a leaf node, as roots often emerge from these points. Remove any leaves from the lower half of the cutting to prevent rot and expose the nodes.
Prepare a pot with a well-draining rooting medium, such as a mix of peat and perlite. Create a hole in the medium with a pencil or finger before inserting the cutting; this helps preserve any rooting hormone. Insert the cutting about one-third of its length into the hole, gently firming the medium around the stem.
To create a humid environment, cover the pot and cutting with a clear plastic bag, ensuring the bag does not touch the foliage. Place the covered pot in indirect light, avoiding direct sunlight which can scorch the cutting. Maintain consistent moisture in the rooting medium, checking daily and watering lightly if the top feels dry. Rooting occurs within 2 to 4 weeks, indicated by new leaf growth or resistance when gently tugged.
Propagating by Seed
Propagating bleeding hearts from seed is a slower process but can be a rewarding endeavor, especially if aiming for genetic diversity or a large number of plants. Seeds are collected from the green pods that form after blooms fade; these pods reveal shiny black seeds when broken open. Plant these seeds soon after collection, ideally in late summer or fall.
Bleeding heart seeds require a period of cold stratification to break dormancy and encourage germination. If sowing outdoors in the fall, nature provides this cold period over winter. For indoor sowing, cold stratify seeds in a refrigerator for 6 to 8 weeks, often in damp peat or vermiculite, before planting.
Sow the stratified seeds about half an inch deep in a well-draining seed-starting mix. Maintain consistent moisture without overwatering, as soggy conditions can lead to rot. Germination can take several weeks to months, occurring when temperatures are between 40 to 55 degrees Fahrenheit. Once seedlings develop a few sets of true leaves, they can be pricked out and transplanted to individual pots. Plants grown from seed may take two to three years to mature and produce flowers, and hybrid varieties may not grow true to the parent plant.
Aftercare for Newly Propagated Plants
Consistent watering is important for newly propagated bleeding heart plants, regardless of the method used. Keep the soil consistently moist but never waterlogged, as excessive wetness can lead to root rot. Monitoring soil conditions daily helps ensure adequate hydration.
New plants thrive in partial shade, especially during the hottest parts of the day. Placing them in a location with morning sun and afternoon shade is ideal, as direct, intense sunlight can stress young foliage. Protecting them from extreme weather conditions, such as strong winds or sudden temperature drops, is also beneficial for their establishment.
Fertilization is not needed during initial establishment; rich, organic soil provides sufficient nutrients. If transplanting plants started in pots to their final garden location, gradually acclimate them to outdoor conditions over about a week by exposing them to increasing amounts of sun and wind. This “hardening off” process helps them adjust to the outdoor environment and reduces transplant shock.