Mexican hat, scientifically known as Ratibida columnifera, also referred to as upright prairie-coneflower, presents an interesting challenge for landowners and those managing natural landscapes. Belonging to the Sunflower Family, this native perennial is a resilient plant, adapted to both cool and warm seasons. It’s characterized by its long lifespan, greening up in the fall and maintaining rosette-type leaves throughout winter. As spring arrives, it begins stem elongation for flowering, typically blooming from April through October. This plant’s persistence is notable; it regrows each fall from a perennial rootstock and can also sprout from seeds produced in previous years. Furthermore, Mexican hat can expand its presence through short underground rhizomes, contributing to a denser plant stand.
The plant’s reproductive cycle involves seeds housed in distinctive, long-peduncled heads. Interestingly, these seedheads are home to native weevils whose larvae feed on the seeds, or achenes, consuming the seed’s stored energy or endosperm. These larvae also undergo pupation within the seedhead before emerging as adults. This natural interaction highlights the complex ecosystem surrounding the Mexican hat.
A common question arises regarding the management of Mexican hat, often with the goal of limiting its growth and spread to encourage other vegetation. Creating an environment less favorable for Mexican hat usually involves promoting a robust grass cover. The success of this approach hinges on the existing grass species at the location and the presence of valuable seed species in the soil seed bank, which can respond positively to land management actions.
Currently, there is limited formal research from agencies, universities, or industry specifically addressing the control of Mexican hat through repeated mowing. However, mowing is recognized as a method to reduce the plant’s photosynthetic area, potentially hindering its growth and, importantly, reducing flowering and seed production. The effectiveness of mowing on perennial plants like Mexican hat is significantly influenced by the timing of mowing, prevailing environmental conditions, and the frequency of mowing. While mowing can suppress the plant and limit its spread, its capacity to eradicate Mexican hat entirely is not well-documented.
It’s important to consider what vegetation might replace Mexican hat after mowing and how to prevent bare soil surfaces from developing. Bare soil is a prime location for annual weeds to germinate, unlike areas with good grass cover. Therefore, assessing the existing plant community, especially the grasses growing beneath the Mexican hat, is crucial. These grasses could benefit from mowing, potentially shading out the Mexican hat and providing beneficial soil cover that enhances rainfall infiltration and reduces runoff. Other plants present in the soil seed bank will also respond to mowing, particularly those that germinate after soil disturbance. In regions like Kendall County, disturbed soils can lead to an increase in various weeds. There is concern that reducing perennial cover might result in a surge of annual weeds that are difficult to manage, such as Malta starthistle and woolly distaff thistle, which are already present in the area.
Any management strategy should aim to minimize bare ground exposure to prevent soil erosion caused by rainfall. Protecting the existing soil is paramount, as soil cover and depth are critical for water retention, which in turn supports a healthier and more diverse landscape for both grazing animals and wildlife.
In the context of Mexican hat management, mowing can be a valuable tool to decrease seed production and accumulation in the soil, reduce the plant’s sunlight interception and shading effects, and encourage the growth of native grasses. It’s crucial to understand that a single mowing will not eliminate Mexican hat. As a perennial, it will resprout from its root crown – a key difference from managing annual plants. Timing the mowing to coincide with the appearance of the first Mexican hat flowers may be the most effective approach to achieve management goals.
Kendall County is situated within the Edwards Plateau vegetation region, originally characterized as an oak savanna. This environment was a grassland interspersed with scattered live oak and shin oak trees, supporting a rich diversity of plant and animal species. From an integrated pest management perspective, winter prescribed burning could also serve as a tool to suppress or set back Mexican hat.
When considering mowing, it is advisable to start by leaving an unmowed strip of Mexican hat. This allows for a direct comparison to assess the effectiveness of mowing in achieving the desired outcomes. Taking seasonal photographs at fixed points in both mowed and unmowed areas provides a visual record for evaluation. Understanding whether a management tool is effective requires a method of evaluation.
For landowners in Kendall County and surrounding areas facing similar concerns, reaching out to local experts is highly recommended. Mr. Stephen Zoeller, the Kendall County Extension Agent for Agriculture and Natural Resources, based in Boerne, can provide valuable localized advice. He can be contacted by phone at 830/249-9343 or via email for tailored guidance on managing Mexican hat on your land. This local expertise can be invaluable in making informed management decisions.
This information is intended to provide a foundational understanding of Mexican hat and potential management strategies, particularly mowing. Effective land management requires careful observation, consideration of local conditions, and often, consultation with regional experts.
