Knox College
OP-10: Landscape Management

The College uses the four-tiered IPM approach for the 7 acres of athletic fields we have as well as the approximately 23 acres of grounds on campus. Chemical control is always the last resort. We have visual thresholds and monitor fungal and insect pest damage. We try to maintain healthy plants with limited excess nutrient availability. Only in situations where weather or density will not control an issue do we use chemical control to prevent loss of turf. No control is used on trees or non-turf plant material. The 23 acres of grounds on campus are not treated with chemical pesticides. The Green Oaks Biological field station includes a restored prairie that is burned annually, as well as old-growth and new-growth forests that are managed for biodiversity. The property is carefully managed for invasive species with mechanical methods and occasional targeted herbicide applications.

Knox College maintains a heavy focus on sustainable landscaping. One of the most important aspects of that is plant selection for various locations. Putting the appropriate plants in selected areas keeps maintenance inputs down. It allows us to use less water and fertilizer to maintain plant health. We also do a great deal of plant pruning. Opening up the canopy allows for better air movement and reduces disease and fungal growth. Knox uses about 200 cubic yards of mulch annually. Mulch allows for improved soil moisture without the need for irrigation and helps keep down weeds. All of the mowing on campus is done to recycle grass clippings. At no time to we ever bag or remove clippings from the lawn. This allows fertilizer inputs to remain very low. The Grounds department also incorporates organic fertilizers into both the plantings and turf as well as PH-changing components like lime and humic acid, to make different nutrients available at certain times of the year and reduce the need for additional fertilizer. We maintain a very high disease threshold. Unless key grounds personnel believe the tree, plant, or turf cannot survive the pest, chemical treatment is avoided.

Existing plant material is almost always reused on campus. There are a few times every year when plants have to be removed due to construction or projects. When this happens we do our best to transplant the material in another appropriate location. The removal of plant material is only considered when safety is concerned. Although not a popular choice, occasional trees must be removed if they are deemed unsafe. This recommendation is usually given by a certified arborist if it is not immediately obvious. Most of the plantings on campus consist of a mix or solely of native material. Plant selection is the most important part of IPM. There are a few invasive species that we deal with on campus. In the case of Japanese beetles we occasionally have to use chemical treatment to save existing plants. Most invasive weeds are controlled by maintain healthy turf through proven cultural practices.

grass clippings are left on all lawns, branches and other yard waste is mulched

Sand top dressing - add organic matter (peat moss usually limited to athletic fields) aerification to open up hard soils, don't heavily manage turf through chemical use or fertilization - run bare minimum of U of I recommendations on NPK use. Supplemented with polycoated fertilizers rather than sulfur coated.

Locally quarried mason sand and rock, use some lime to adjust soil pH

More efficient sprinkler heads (less water but more coverage), allow soaking time to prevent runoff

Grounds uses a calcium chloride-based product to melt icy sidewalks but uses sand whenever possible to avoid use of salt.