Can spread vegetatively from cut stems and pieces of rootstocks. However, vegetative spread is generally limited. Each capsule contains approximately 120 seeds and an average plant may contain approximately 900 capsules. Seeds may also be dispersed by wind, livestock, and other animals. Humans can inadvertently carry seeds on clothing and shoes.
Spring germinated seeds generally have a higher survival rate than seeds which germinate in summer.
Seeds are small and contain small food reserves so germination must occur in conditions where photosynthesis can occur rapidly. Competition An extremely successful invader of wetlands that have undergone disturbance. Expansion in wetlands can be rapid due to the prolific seed production and high seed viability. Purple loosestrife germinates at such high densities that it out competes native seedlings. In addition, loosestrife has low nutrient requirements, but has a high capacity for nutrient uptake.