As environmental conditions allow, the capsule dehisces often propelling the seeds up to 5 m from the parent plant. Each plant produces from ten to 50 capsules with a seed yield range of 200 to 250 seeds per plant. Animals, birds, insects, equipment, seed, hay, grain, and the natural dehiscence of the capsule are all dispersal agents for leafy spurge. Seeds can remain viable in the soil for 5 to 8 years. Ninety-nine percent of viable seeds will germinate in the first 2 years.
Temperature is the most important requirement for germination.
Alternating freezing and thawing, wet and dry periods, and shortened photoperiod promote germination. If adequate moisture is present, germination can occur throughout the growing season. Although a successful seed producer, the primary way an established patch of leafy spurge spreads is through its extensive lateral root system. Vegetative reproduction occurs from both crown and root buds. The majority of the plants in the center of a patch are the result of crown buds, while the plants growing on the edge of a patch are primarily from lateral root buds.