From my perspective as a Bleeding Heart (Lamprocapnos spectabilis), the answer is a definitive yes, but it is a gentle, patient spreading. I do not send out runners like an aggressive mint or sow myself with wild abandon across your garden. My method of spreading is subterranean and deliberate. I grow from rhizomes—fleshy, horizontal underground stems that act as storage organs and growth centers. Each growing season, my rhizome network expands slowly outward. New growing points, or "eyes," develop along these rhizomes, which in turn send up new stems and fern-like leaves in the spring. This is how my clump gradually becomes wider and more substantial each year, a quiet and steady conquest of the soil around me.
While my primary means of spreading is through my rhizomes, my above-ground existence also contributes. After I display my iconic, heart-shaped flowers in spring, I may produce small, elongated seed pods if conditions are favorable. These pods dry and eventually split open, potentially dispersing my black, peppercorn-like seeds a short distance away. However, this method is far less reliable than my rhizomatic growth. The seeds often require a period of cold stratification to germinate, and even then, germination can be inconsistent. You are far more likely to notice my spread from the gradual widening of my clump than from volunteer seedlings popping up around your garden.
To understand my spread, you must understand my entire life cycle. I am an ephemeral plant, meaning my above-ground growth is relatively brief. I emerge with great vigor in the cool spring, flower spectacularly, and then, as the heat of summer arrives, my foliage begins to yellow and die back. I retreat entirely underground to my rhizomes to wait out the hot, dry summer. This dormancy is a crucial part of my rhythm. The energy I gathered during my spring growth is stored in my rhizomes, fueling my expansion for the next season. My spreading is therefore not a continuous process but an annual event that occurs during and after my period of active growth, before I retreat for my summer rest.
If you find my gentle spreading is more than you desire, you can easily work with my natural growth habits to control me. The most effective method is division. Since I grow from a clump of rhizomes, you can simply dig up my entire plant in early spring as I am just emerging, or in the fall after I have gone dormant. Using a sharp, clean knife or spade, you can cut my rhizome mass into several smaller sections, each with at least one growing eye or stem. Replant one section in the original location and either pot up the others to share or relocate them to a new part of the garden. This process actually rejuvenates me and prevents the center of an older clump from dying out. To prevent self-seeding, you can deadhead my flowers after they fade, removing the seed pods before they have a chance to mature and disperse.
