Santiago Hills Park – Pesticide-Free Maintenance

Santiago Hills Park – Pesticide-Free Maintenance Pilot Program



In response to concerns from members of the community regarding pesticide use in city parks, Santiago Hills Park was selected for a pesticide-free maintenance pilot program. The use of all pesticides, including herbicides, rodenticides, and insecticides were eliminated as part of regular maintenance practices. The program started on August 29, 2019 and concluded on August 28, 2020. Over the course of the year, staff evaluated operational and financial impacts of eliminating pesticides while providing a pesticide-free maintained park for community members who prefer this option.  The intent for the pilot program was to be a representative of options for future consideration throughout the park system if determined to be safe, functional, and acceptable to the community at-large. 


Final Program Summary-Fall 2020



 At the end of the one year pilot program, 85% of the turf area is pink clover.  The turf, which comprises 95% of the park, is a hardy Kikuya grass that competes well with the clover, however, as the clover continues to expand, its coverage and influence is expected to be equally hardy and eventually be the prominent ground cover. While there was a slight increase in weeds throughout the year in the planters, tree wells, and hardscape, mechanical management was effective in controlling weeds in those areas. No safety concerns were noted, and the park remains actively used by the community.  

Pursuant to City Council direction at the July 14, 2020 City Council meeting, Santiago Hills Park, along with now Killefer and La Veta Parks, will be maintained pesticide free, allowing the community pesticide free park options within the City of Orange. All three parks will continue to be monitored, and if conditions cause safety or accessibility concerns, staff will evaluate steps that can be taken to address the issues. 

Update-May 2020



The Santiago Hills Park pesticide-free maintenance pilot program has been in place now for 8 months.  During the course of this year long program, staff has been assessing several factors to get a better understanding of the impacts of eliminating the use of pesticides. Factors assessed include the type and percentage of problematic weeds, hardscape conditions, tripping hazards, effects of insects/rodents, and change in appearance (aesthetics).  At the end of April 2020, staff conducted a walkthrough to evaluate park conditions and compare the findings to what was documented at the end of last year. Merchants, the City’s contractor, continues to mow, edge, and perform all other tasks contained in the contract specifications. With the large amount of rain over the last couple of months, there has been a significant increase in broadleaf weeds, mainly pink and burr clover.  As of April, 80% of the turf now contains some broadleaf weeds. The slope alongside the parking lot has seen an increase of 30% in weeds and there is an increase in weeds in sidewalk cracks. The pink clover continues to bloom during the spring season resulting in more bees being attracted to the area while the burr clover has started to produce prickly “stickers.” Staff anticipate the springtime will continue to bring on a robust growth of all plants and weeds. During the final quarter of the program, the effects of the spring growth will be monitored and documented.  If any of these conditions cause safety or accessibility concerns, staff will evaluate steps that can be taken to address the issues.

Update-December 2019


On December 6th staff did the first quarterly walkthrough to evaluate park conditions and compare the findings to what was documented at the start of the program. Merchants, the City’s contractor, has continued to mow, edge, and perform all other tasks contained in the contract specifications. Conditions noted include an increase from less than 3% of broadleaf weeds (primarily clover) to 50% of the turf area now contains some broadleaf weeds, while some areas as large at 100 square feet or more are completely covered by clover. With this increase however, to the average park patron, the overall appearance of the park has not changed. This is a larger increase in weeds then staff expected. The warm fall temperatures and the early rain are suspected to be a major factor in the increase.  Past experience indicates that in the spring time these weeds will proliferate and areas of clover growth will flower, attracting more bees.  Other conditions noted in the walk through include an increase in turf damage caused by crows feeding off of worms and grubs, leaf curl caused by Aphids (a type of bug) in newly added plants near the restroom building, and an increase in weeds in sidewalk cracks. Staff will continue to monitor these conditions and address sidewalk weeds with weed-whacking at the surface level. If, over the course of the next several months, these conditions create safety or accessibility issues for park users, staff will evaluate additional steps (at an additional cost) that can be taken to address the concerns (i.e. increase mowing frequency, hand-weeding cracks for a better effort to remove roots, evaluate non-toxic insect/bug repellants, etc.).

Update - October 2019


At the request of City Council, staff commissioned Weck Laboratories to complete toxicity soil testing at the park. Five samples were taken from different areas of the park and sent to the lab at the start of the pilot program to establish a baseline.  The results indicated no detection of Glyphosate, 2,4-D or Dicamba in any of the samples.