Cattail Germination

Need for Control

• Cattails are a prolific species that can readily dominate wetland stands. While cattails do provide habitat value to certain types of wildlife, monotypic wetlands are less productive overall than similar, more diverse habitats. In addition, cattails are a favorite roosting habitat for blackbirds. Blackbirds can inflict substantial damage to any crops in the vicinity. Understanding germination requirements is a fundamental part of effectively controlling the species. Often, the best forms of control involve using a combination of approaches over a series of time.

Temperature Requirements

• Cattails require relatively high temperatures to germinate. Maximum germination rates occur when temperatures are between 77 and 86 degree Fahrenheit. Many ponds are equipped with water control mechanisms. In freeze-prone areas, the cattail population can be controlled by maintaining low water levels during the fall and winter. Freezing the roots of cattails will eliminate a portion of the existing population. However, in these areas, seeds may overwinter until warm temperatures are reached. Consequently, new plants are still likely to emerge following the return of warm weather.

Oxygen Requirements

• Although cattails will germinate in moist conditions, the species produces the highest germination rates among seeds submerged in shallow water. Specifically, cattail seeds favor 2 percent oxygen levels during germination. Due to oxygen and light penetration requirements, cattails will not germinate in water more than 1/2 inch deep. Consequently, controlled, shallow flooding with as little as 1 inch of water can successfully prevent cattail germination. Be advised, significant precaution must be taken with this approach in order not to enhance the problem by flooding previously unsaturated soils.

Light Requirements

• Light availability is a critical component of cattail germination. Exact intensity requirements vary among species, but in general, cattails favor higher intensity light over low intensity light during germination. Germination rates among cattails in full sunlight are as high as 99 percent. Conversely, germination rates within established stands, or in deep water, are far lower due largely to reduced light penetration.