Soil Health

What’s changing with fertilizers in Connecticut, and how to shop smarter this fall?

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By Dr. Avishesh Neupane, UConn Soil Nutrient Analysis Lab

If you shop for fertilizer in Connecticut this fall, you will see some labels missing from the shelves and more paperwork behind the ones that remain. The reason is new state rules targeting certain ingredients and how they are documented. 

A compost pile on the edge of a woodlineOn October 1, 2024, Connecticut banned products made from biosolids or wastewater sludge that contain PFAS from being used or sold in the state as soil amendments. Biosolids are the treated solids left from wastewater treatment. Some products made from them were marketed for lawns and gardens in the past years. Connecticut’s new law closed that door to reduce PFAS in soils and runoff. 

So what are PFAS and why the crackdown? Per- and polyfluoroalkyl substances, or PFAS, are a large class of “forever chemicals” added to products to resist water, grease, and stains. They do not break down easily and can build up in people, soil, and water. Health agencies have linked PFAS exposure to certain cancers, immune system effects, and developmental concerns, which is why Connecticut has been tightening rules to limit the entry of these chemicals into our environment. 

Effective July 1, 2025, the legislature extended the PFAS biosolids restriction from soil amendments to fertilizers as well. The law also requires manufacturers and registrants to provide a certificate of compliance showing that any fertilizer or soil amendment that contains biosolids is free of PFAS. Products that do not meet the standard must be removed from Connecticut shelves.  

What this means for your yard and vegetable beds is simple: expect fewer “biosolids-based” fertilizers on the market and expect clearer paperwork behind any products that remain. If you relied on those products for lawns or gardens, it is time to switch to other nutrient sources. 

How can you read labels to avoid fertilizers and Soil amendments with PFAS? 

  • Check the ingredients panel. Look for words like “biosolids,” “sewage sludge,” “municipal waste,” or “residuals.” If you see those, consider a different product.  
  • Look for an analysis or ingredient list that spells out plant, animal, or mineral sources, such as feather meal, alfalfa meal, composted poultry manure, sulfate of potash, or rock-derived nutrients. These indicate non-biosolid ingredients. 
  • Ask your retailer. If a product contains biosolids, the maker must keep a certificate on file stating the product is compliant. Retailers should know whether a certificate exists for what they sell. If they cannot confirm, do not buy.  

Safer sourcing ideas that are easy to find 

  • Start with a soil test. Match products and rates to what your soil actually needs. The UConn Soil Nutrient Analysis Laboratory provides routine tests with fertilizer and lime recommendations for home lawns and gardens. 
  • Yard-waste compost and leaf mulch made from leaves, grass clippings, and wood chips are reliable ways to add organic matter to the soil. 
  • Use animal-based fertilizers like composted poultry manure or feather meal, plant-based products like alfalfa meal, and mineral fertilizers like sulfate of potash and limestone.  
  • Biosolids are not allowed in certified organic production. “OMRI Listed” inputs follow the USDA National Organic Program, which prohibits sewage sludge. Choosing “OMRI Listed” products can be a practical way to avoid biosolids entirely.  

A few quick FAQs 

  • Do I need to throw away the fertilizer I already own? Yes, but only if it contains PFAS or biosolids with PFAS. The new rules apply to the sale and use in the state. Contact your town’s household hazardous waste program for proper disposal guidance.  
  • Will PFAS show up on a routine soil nutrient test? Standard nutrient tests do not include PFAS. If you are concerned about legacy PFAS on a property that received biosolids, specialized testing is required. Your local Extension office can help you locate appropriate resources. 
  • What about compost from my town? Ask what goes into it. Compost made only from leaves, grass, wood, and animal waste is a safer choice for home gardens under the new rules. 

Connecticut has removed PFAS-containing biosolids and fertilizer products from the garden marketplace. Expect clearer documentation from manufacturers and fewer sludge-based products on shelves. With a little label reading and a few ingredient swaps, you can keep building healthy soil while staying on the right side of the regulations.  

The UConn Home & Garden Education Center supports UConn Extension’s mission by providing answers you can trust with research-based information and resources. For gardening questions, contact us toll-free at (877) 486-6271, visit our website at homegarden.cahnr.uconn.edu, or reach out to your local UConn Extension center at  extension.uconn.edu/locations 

This article was published in the Hartford Courant October 11, 2025

Fall is a Great Time to Lime and Fertilize Lawns

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By Dawn Pettinelli, UConn Home & Garden Education Center

With the end of summer drawing near and hopefully bringing cooler temperatures and needed precipitation, now is a great time to attend to your lawn. While some of us are reducing the size of our lawns and adding native plants, in many cases lawns still serve a valuable purpose for practical uses, recreation and to set off plantings. Traditional cool season grasses like Kentucky bluegrass, fescues and rye grasses require a higher pH and more fertility than our native soils provide. Right now is the perfect time to add limestone and fertilizer, if needed. Improved soil conditions will assist lawns recovering from the heat and drought stresses of summer. Also, the cooler fall temperatures allow turfgrasses to resume active growth.

Having your soil tested before purchasing limestone and fertilizer is always a wise move. Check out the UConn Soil Testing Lab’s website or give them a call at (860) 486-4274. Many of our soils tend to be acidic with a pH of 5 or so. You might remember that the pH scales ranges from 1 to 14 with 7 being neutral and values below that acidic and above that alkaline. Cool season turf grasses prefer a soil pH in the mid 6’s. When the soil pH is too low, it reduces the amounts of nutrients that are available to turf grasses even if fertilizer has been applied, increases the solubility of toxic elements like aluminum and can cause a decrease in good root formation, contribute to thatch accumulation and affect soil microbes.

Fortunately adjusting your soil’s pH is relatively easy and affordable. Limestone can be purchased either as a ground white powder or in earth tone pelletized forms. There are two main types. Calcitic limestone consists predominantly of calcium carbonates while dolomitic limestone contains both calcium and magnesium carbonates. Usually, dolomitic limestone is more commonly found as it is mined locally and it is fine to use as magnesium is an essential nutrient.

A person pushing a spreader
Photo by dmp2024

Typically, limestone is applied at rates of 50 pounds per 1000 square feet. If the soil pH needs to be raised significantly, additional limestone can be applied either spring/fall or at 30-day intervals. Once your soil pH reaches the mid 6’s, a maintenance application of 50 pounds/1000 square feet every other year should suffice. Do keep in mind that limestone does take anywhere from 6 to 18 months to change the pH depending on environmental conditions. While some more costly products are advertised as ‘Fast Acting Lime’, studies comparing them to traditional ground or pelletized limestone are inconsistent. If using these products, just follow the instructions on the package.

Choosing a fertilizer is often a confusing task considering the vast selection available. All plants need at least 18 different elements to grow. The 3 that are most often deficient in our soils and components of most fertilizers are nitrogen (N), phosphorus (P) and potassium (K). So, the 3 numbers found on a bag or box of fertilizer, like 10-10-10 or 27-4-6 represent the percent of total nitrogen, available phosphate, and water-soluble potassium, respectively. For instance, a ten-pound box of 10-10-10 contains 10 percent or 1 pound of total nitrogen, and another 10 percent or 1 pound each of available phosphate and water-soluble potassium.

A law passed in 2013, limits the amount of phosphorus that can be applied to established lawns because it is the number one inland freshwater pollutant. Lawn maintenance fertilizers sold in Connecticut will typically have analyses like 30-0-4, 29-0-5 or 10-0-6. While phosphorus applications are prohibited on established lawns, fertilizers with phosphorus can be used when seeding, sodding or overseeding.

Fertilizers are also grouped as either those containing water-soluble nitrogen (WS) of water insoluble nitrogen (WIN). Look for a fertilizer that contains both. That way some nitrogen will be immediately available to your lawn and some will be released slowly over time. Fertilizers containing solely soluble N will produce rapid results but can easily burn if over applied and since some forms of nitrogen are readily leached from the surface soil, more frequent fertilizer applications may be necessary. No more than 1 pound of nitrogen per 1000 square feet should be applied at one time. If grass clippings are left in place then only 2 pounds of nitrogen per 1000 square feet of turf area will be needed each year. The best times to fertilize lawns are in September and in late April through the end of May. Avoid using too much nitrogen as it can lead to increased susceptibility to diseases and lower resistance to stress. If in doubt as to how much lime and fertilizer to apply, consider having your soil tested.

The UConn Home & Garden Education Center supports UConn Extension’s mission by providing answers you can trust with research-based information and resources. For gardening questions, contact us toll-free at (877) 486-6271, visit our website or reach out to your local UConn Extension center.

This article was published in the Hartford Courant September 20, 2025

Best Practices for Soil Sample Collection: How You Sample Matters

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By Nora Doonan, Soil Science Graduate Student, UConn Department of Plant Science & Landscape Architecture

Auger full of soil
Auger collection of a 6-inch soil core. Photo by Nora Doonan

Soil testing begins with the homeowner, gardener, and farmer. The most critical step in soil testing is soil sample collection. Soil testing can help growers make informed decisions about fertilizer application, soil amendments, and soil health. A standard nutrient analysis can chemically extract calcium, magnesium, phosphorus, potassium, sulfur, iron, manganese, copper, zinc, aluminum, and boron from the soil. Other tests can also determine the pH and organic matter content of the soil. Poor sample collection can cause errors in the testing results, potentially leading to inaccurate nutrient recommendations and lowered crop productivity. Consistent and proper sampling procedures allow you to make future comparisons of the same sampling area. They also allow you to limit unnecessary nutrient applications that could lead to environmental contamination through the loss of nutrients. In addition, soil testing costs money and can influence the total cost of fertilizer and amendments needed for application. Following proper sample collection procedures can help you avoid unnecessary expenses.  

The first step in collecting a soil sample is to determine an area in which the sample will be collected. You will want to select an area that has similar physical appearance, slope, drainage, limestone or fertilizer treatments, and intended plant usage. For example, if your front lawn has a steep slope compared to a flat side yard, you will want to collect a separate sample from both of those areas, rather than grouping them together as one sample.  

The second step is to have a clean bucket and tool for collecting soil. This can be done more easily with a spade, auger, or probe. You will want to collect 10 or more random subsamples from across the selected area, that way the sample submission is representative. Flowers, vegetables, and small fruits soil samples should be collected to a depth of 6-8 inches. A depth of 6 inches is widely accepted since it represents the zone in which there is highest root density and nutrient uptake for many plant species. Soil samples collected for turf should be collected to a depth of 3-4 inches, since most turfgrass roots are concentrated in the top 4 inches of soil. Tree and shrub samples should be collected to a depth of 8 to 10 inches. These are the recommended sampling depths from the UConn Soil Nutrient Analysis Laboratory. It is also important to make sure that the sample is collected vertically, rather than at an angle. Sampling at an angle can affect the sampling depth and lead to inaccurate lab results.  

Next, you will want to mix the subsamples together to break up the clumps while removing stones and debris. Once mixed, scoop out at least 1 cup of soil into a zipper lock bag and label the bag with a sample identification. Fill out the submission form with the same sample identification and label a crop code. Crop codes are key for making recommendations. Different crops have different needs. For example, blueberry plants prefer acidic soils that have a pH between 4.5 and 5.0 while turf prefers a pH between 6.0 and 7.2.  

Soil samples can be collected at any time of the year, as long as the ground is not frozen, but should not be collected when the soil is very wet or within six to eight weeks of a fertilizer or lime application. Many samples are submitted in the spring to prepare for the growing season, but a fall soil sample submission can be very beneficial for soil pH and some fertility corrections. Limestone and sulfur can be added to the soil in the fall to allow plenty of time for the lime to neutralize soil acidity and bring pH to target levels by the spring. Sandy textured soils should be sampled every 2 to 3 years and clay soils should be sampled every 3 to 4 years. If a soil test reveals that a large correction in pH or fertility is necessary, it may be a good idea to have your soil tested again in 1 year to evaluate the correction. More information on soil testing services and soil sampling procedures can be found at the UConn Soil Nutrient Analysis Laboratory. 

The UConn Home & Garden Education Center supports UConn Extension’s mission by providing answers you can trust with research-based information and resources. For gardening questions, contact us toll-free at (877) 486-6271, visit our website at homegarden.cahnr.uconn.edu, or reach out to your local UConn Extension center at cahnr.uconn.edu/extension/locations. 

  

This article was published in the Hartford Courant August 16, 2025

Set Your Lawn Free

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By Dawn Pettinelli, UConn Home & Garden Education Center

Dandelions growing uncontrolled in a lawn.
Photo by Dawn Pettinelli

For many, the sight of a lush green lawn brings about the desire to cast off one’s shoes and stroll through the sun-warmed grass feeling the soft verdant carpet below. Lawns, or at least grassy areas, are a ubiquitous part of almost every home outside city limits. While admittedly that perfect lawn is a source of curb appeal and homeowner pride, in recent years considerable attention has been given to the ecological and environmental costs of maintaining turf that is the envy of the neighborhood.

Managed turf grass areas, including golf courses and park areas cover about 8 percent (400 square miles) of the land area in Connecticut. That perfect lawn typically requires supplemental irrigation, fertilizer, regular mowing and often pesticide applications. Water could be better used for drinking, other domestic uses and just left in natural systems. Excess nutrients as well as pesticides can be found in ground and surface waters causing both human health as well as ecosystem problems. While some are turning to electric mowers and blowers, gas-powered equipment dependent more on fossil fuels, are most prevalent (at least in my neighborhood) contributing to climate change.

So what is a residential lawn owner to do? The authors of Redesigning the American Lawn were among the first to coin the term “freedom lawn.” So, what is a freedom lawn? Basically, anything that is green is allowed to grow. That would include dandelions, self-heal, violets, bluets, buttercups, clover and wild strawberries to list a few of those so-called “low growing broad-leaved plants”. By my definition, weeds are plants growing in the wrong place, so the plants are weeds no longer when accepted as part of the lawn.

One of the greatest reasons for encouraging a variety of plants to inhabit turf areas is that the world is facing a critical loss of biodiversity. There are significant declines in beneficial insect, native plant and bird populations, along with other living organisms. While that lush green lawn offers aesthetic pleasure to some, it does little to provide habitat or food for creatures other than problematic ones like grubs or chinch bugs.

A mixed grass- herbaceous plant lawn will contain flowering plants for pollinators and other beneficials. Various plant species have varying root systems. Some have deep taproots that break up compacted soil and bring up minerals. Others have more fibrous root systems that are continuously turning over added organic matter to the soil. A variety of plants along with their root exudates and associated microbes can help aggregate the soil, improving air and water passage. Porosity plus water holding capacity can be increased as well as lessening the potential for topsoil erosion. A healthy plant community usually portends a healthy soil.

Leaning into a freedom or pollinator lawn does not mean digging up one’s entire lawn and reseeding it although that is one option. Two seed mixes that I have seen advertised are Flawn and Fleur de Lawn. Both contain a mixture of fescues, microclover and the latter, some other flowering species. Probably greatest success with these seed mixes would be achieved starting with bare soil.

One can start encouraging biodiversity and pollinator plants by discontinuing the use of herbicides and allowing some flowering plants to move in. Often, they can be mowed before they set seed. When reseeding bare spots, use more drought tolerant fescues or native grasses like little bluestem to reduce the need for irrigation, once established. Higher mowing heights up to 3 or 4 inches will encourage deeper rooting of all plants making them more resilient during periods of drought.

Learn about the benefits of some of the low-growing broad-leaved plants that want to call your lawn home. Clovers add nitrogen to the soil reducing the amount of fertilizer necessary. Violets are host plants for the endangered regal fritillary. Dandelion greens are a great source of vitamins A and C. It is true that many of these plants are not native, but neither are the cool season turf grasses normally found in lawns.

In many yards, keeping part of it in lawn is essential for children’s play and sports activities, pet areas and entertaining. Take a tour of your yard and determine where a lawn makes sense and where it might be more appropriate for woody plants, ornamental beds or even a vegetable garden. Steep slopes or perpetually shaded areas may be best for groundcovers. Areas where water frequently collects after heavy rains might be more suitable for a rain garden.

However small, every effort to encourage biodiversity, provide for our beneficials and improve soil health is a step in the right direction. Rethinking your lawn areas might be a good place to start.

For information on lawns or any other gardening topic, call the UConn Home & Garden Education Center (toll-free) at (877) 486-6271 or email us at ladybug@uconn.edu or visit our website, www.homegarden.cahnr.uconn.edu.

This article was published in the Hartford Courant May 18, 2025