Background

The Kentlands Citizens Assembly (KCA) is a nationally recognized neo-traditional planned community comprised of 942 single-family homes and townhomes in Gaithersburg, MD. In 2011, GO GREEN, an environmental group sponsored by the Kentlands Community Foundation, raised the issue of landscaping chemical use with the KCA board. It wasn’t until 2013, after a couple of years of residents demanding change, that the board finally allowed for one test plot on the Kentlands Clubhouse lawn. Despite pushback from the KCA Environmental Management Committee (EMC), a separate committee, the Turf Committee, was created to set up and run a 5-year side-by-side experiment comparing chemical and organic protocols starting in 2014. They reached out to international sustainable landscape expert—and A.I.R. advisory board member—Paul Tukey to consult with them. After trying to work with Kentland’s current landscape contractor with no success, A.I.R. was brought in to run the experiment.

Chemical vs. Organic Lawn Care Experiment Setup

At first, the Turf Committee selected turf plots across the community based on two criteria—aesthetics and organics. Within each category, there was a ranking system. For the organic criteria, it was an “A”, “B”, or “C”, with “A” being the highest level of aesthetics. For the organic criteria, it was a 1, 2, or 3 with 3 being the most organic possible.  An area designated as 1A meant that the area had to look as close to a golf course green, but only using organic products. By contrast, an area designated as 3C meant that appearance was not an issue and chemicals such as RoundUp could be used as freely as possible.  As soon as they had our proposal for this they realized the cost and documentation of the experiment were too much.

They revised their map with only two criteria (1A and 1B) instead.  The 1A areas would receive 5 applications (1 compost top dressing, 3 compost tea applications, and 1 natural, organic fertilizer application) as well as extra aeration in the spring, while the 1B areas would receive 4 applications (3 compost tea applications and 1 natural, organic fertilizer application).

The biggest differences between the first map and the second map were: (1) the 1A areas received a compost top dressing that was done in the spring in conjunction with the aeration, (2) they removed curb strips and medians turf, opting for those areas to be chemically treated, and (3) the organic weed control extended into any mulched/treed areas that were within any of the classification areas.

When it was all said and done there were 81,471 square feet (roughly 1.87 acres) of turf in the A1 areas, and 243,153 square feet (roughly 5.58 acres) of turf and mulched/treed areas (which comprised 72,105 square feet of the 1B 243,153 square feet total) in the 1B areas.

Unexpected Variables Part 1

The experiment was soon underway, but there were important variables the committee did not realize they could control—the cutting height of the mowers—and they could not control—the amount of irrigation since the Kentlands had no working irrigation systems on-site. Mowing height plays an important if not greater role than product use in the success of a natural, organic lawn care program. For much of the beginning of the first year, the cutting height of the mowers was between 3 inches and 3.5 inches across both the chemical and organic plots. We recommended they raise the height of the mowers to 4 inches to encourage deeper root growth, increase stress tolerance, and create protection from weeds for all plots. Within weeks of adjusting the turf quality improved significantly.

This improvement in the turf was also coupled with one of the wettest years in a while (42.37 inches of rainfall in 2014). Taking care of the soil is the foundation of a natural, organic lawn care program, and like humans it requires air, food, and water to survive. With the Kentlands not having any working irrigation system the rain helped water and keep everything green year round.

2014 First Year Results

The first year the total cost for the organic program was $39,808.04. The Turf Committee was happy with the results. However, they were not sure if it was because of the organics, the large amount of rain, or the raising of the mowers cutting height. Along with this, they did not anticipate people being more concerned about weeds in the mulch areas and the amount of communication that would be required. The mulch beds were not originally discussed as part of the experiment and contractor responsibility for them was unclear. As for communication a lot of residents were unaware of the new organic protocols and would often flee when an application was being done fearing it was a chemical application. The Turf Committee fixed both of these issues for the second year. For the mulch beds, any mulch bed areas in organic areas were to be treated with organic protocols. For the lack of communication, they had large signs printed and to be displayed during natural, organic applications the following year.

Unexpected Variables Part 2

For the second year, the Kentlands decided to do an additional compost top dressing, aeration, and overseeding application in the 1A areas compared to the prior year. Halfway through the season, the MDA revealed at one of the committee sessions for Montgomery County Bill 52-14 that applying compost violated the new lawn fertilizer law passed in 2013. This is because certain composts—not all compost is created equal—contain phosphorous that when applied at the necessary rate violates the law. This required us to find a new product for the second compost top dressing application. That product was a biochar/compost mix.

2015 Second Year Results

The second year the total cost for the organic program—which included an additional compost top dressing, aeration, and overseeding application compared to the 2014 program—was $34,784.61.  We had found efficiencies and ways to reduce costs and passed those savings onto the Kentlands Citizens Assembly. Besides the cost reduction, the Turf Committee was happy with the results of the program. The only issue this year was a severe heat spell that damaged a lot of the Clubhouse Lawn. This was due to the lack of irrigation and the amount of foot traffic the area receives, but the turf quickly recovered after the biochar/compost top dressing and aeration application in the fall. Below is a picture from one of the 1A areas after 2 years of being on A.I.R.’s natural, organic lawn care program:

2016 through 2018

For the next 3 years of the experiment, the Turf Committee has decided to change the protocols for the natural, organic plots by increasing the overall total applications. They now include an aeration, biochar/compost top dressing, and overseeding application in the Spring and Fall, 6 compost tea applications, the ability to apply up to 3 fertilizer applications pending soil test results, and a gypsum application as needed.

The reason overseeding was added to each of the biochar/compost top dressing and aeration applications was that unlike the pure compost we applied the previous 2 years which covers bare spots and prevents crabgrass seeds from germinating, the biochar/compost mix does not. Coupling the biochar/compost mix with aeration and overseeding is not only a weed prevention tool, but a way to increase the turf density and overall turf vigor. Even with all the added applications the total cost is $32,300.

Conclusion

Overall, the organic lawn care program at the Kentlands has been a success. We have found ways to lower costs year after year, while also increasing the amount of applications.  With Montgomery County’s Bill 52-14 going into effect in 2018, now is the best time to get your community to switch to a natural, organic lawn care program.

We have been through the process with one of the largest developments in the county and understand what is required to have a successful transition from a chemical lawn care program to a natural, organic one. It takes commitment, communication, and education. We would be happy to assist you in making the transition. Contact us today by clicking the following link.