If you’re a cat owner trying to reduce your environmental footprint, you’ve likely eyed that mountain of used cat litter with a mix of guilt and frustration. You’re not alone—an astonishing 2.4 million tons of cat litter end up in landfills each year in the US alone. That’s roughly the weight of 240 Eiffel Towers sitting in our waste systems annually.
But here’s the good news: yes, certain types of cat litter can be composted. However, this isn’t as straightforward as tossing banana peels into your compost bin. Cat waste presents unique challenges that require specific precautions and techniques.
Why does composting cat litter matter? Beyond reducing landfill waste, properly composted litter can be transformed from a disposal problem into a resource. Additionally, making this switch is often a gateway to other sustainable pet care practices.
The quick answer: Yes, you can compost cat litter, but only plant-based varieties—never clay or crystal litters. Furthermore, you’ll need to follow specific safety protocols due to potential pathogens in cat waste. With the right approach, most plant-based litters can be safely processed in 30-45 days (though they’ll need much longer aging before use).
Let’s dig into exactly how to do this safely and effectively.
5 Cat Litters You Can Compost vs. 3 You Should Never Try
Plant-Based Options Ready for Composting
Corn-Based Litters
These litters, made from whole-kernel corn, break down completely in 4-8 weeks in an active compost system. They’re naturally clumping and offer good odor control. Brands like World’s Best Cat Litter provide excellent absorption while remaining fully biodegradable.Wheat and Grass Seed Litters
Typically priced between $15-25 per bag, these are among the most affordable compostable options. Wheat-based litters form natural clumps when wet and break down within 4-6 weeks in compost. Swheat Scoop and Smart Cat are popular brands that cats tend to accept easily.Recycled Paper Pellets
Made from post-consumer paper waste, these pellets offer superior odor control among compostable options. They take slightly longer to break down (6-8 weeks) but are excellent for cats with sensitive paws. Yesterday’s News is a widely available option.Pine and Cedar Shavings
These decompose fastest among all options, typically within 3-4 weeks. The natural oils also provide some odor control. Feline Pine offers compressed pine pellets that expand when wet, making it easier to identify used litter for scooping.Coconut Coir Litters
Made from the husks of coconuts, these litters are highly absorbent and break down within 4-6 weeks. CatSpot and other coconut litters are lightweight and nearly dust-free, making them ideal for homes with allergies.
Never Compost These Litters
Clay-Based Clumping Litters
These contain sodium bentonite that never breaks down naturally. Not only will they ruin your compost, but they’re also strip-mined, creating significant environmental damage during production. They’ll form concrete-like clumps in your compost bin.Silica Crystal Litters
These non-biodegradable materials can take over 1 million years to decompose naturally. They’re essentially manufactured sand that will permanently remain in your compost, rendering it unusable.Litters with Synthetic Fragrances or Additives
Many commercial litters contain artificial fragrances, anti-bacterial agents, or other chemicals toxic to soil microorganisms. These additives can kill the beneficial bacteria essential to the composting process.
Why Toxoplasmosis Makes Cat Waste Different from Other Pet Waste
While you might compost rabbit or guinea pig waste without much concern, cat waste requires special handling due to Toxoplasma gondii. This parasite, which can only complete its life cycle in cats, creates oocysts that can survive in soil for up to 18 months.
The highest risk from toxoplasmosis exposure is to pregnant women (where it can cause birth defects) and immunocompromised individuals. For most healthy adults, infection often causes no symptoms or mild flu-like symptoms.
This is where hot composting becomes essential. To destroy these pathogens, compost must maintain a temperature of at least 145°F (63°C) for a minimum of three consecutive days. Unfortunately, most casual backyard composting rarely achieves or maintains these temperatures consistently.
Furthermore, standard composting recommendations of 140°F may not be sufficient for cat waste—research indicates that higher temperatures provide a better safety margin for pathogen destruction.
How to Safely Compost Cat Litter in 4 Simple Steps
1. Create a Separate Composting System (15 minutes setup, $30-50 investment)
Never mix cat litter with your regular kitchen compost. Instead, establish a dedicated system at least 20 feet away from vegetable gardens and water sources.
Recommended containers:
- A dedicated compost tumbler ($40-50) allows for easy turning and contains the material
- Two 18-gallon plastic storage bins with lids, drilled with 1/4-inch ventilation holes ($15-20 each)
The two-bin rotation system works exceptionally well: fill one bin while the second bin processes the previously collected material. This ensures continuous composting without interruption.
Place your system in a sunny location to help achieve higher temperatures, but avoid areas prone to flooding or runoff.
2. Implement Proper Waste Separation (adds 1-2 minutes to daily litter box cleaning)
The most crucial step is removing solid waste before adding used litter to your compost system. This significantly reduces pathogen load.
Effective separation techniques:
- Use a dedicated scoop with small holes that allow litter to fall through while capturing solid waste
- Wear disposable gloves ($5-10 for a box of 100)
- Bag solid waste separately and dispose of it in the trash (or flush if your municipality permits)
A sifting litter box system ($15-25) can make this process more hygienic and efficient by allowing you to separate waste more completely.
3. Master Hot Composting Technique (10 minutes weekly maintenance)
To achieve pathogen-killing temperatures, you’ll need the right balance of materials:
Carbon-to-nitrogen ratio (C:N):
- Used plant-based cat litter: high carbon
- Add nitrogen sources: fresh grass clippings, coffee grounds, or a small amount of organic fertilizer
- Aim for a 25:1 C:N ratio (approximately 3 parts litter to 1 part nitrogen-rich material)
To maintain 145°F+ temperatures:
- Turn the compost every 2-3 days using a pitchfork or compost aerator tool
- Monitor temperature with a compost thermometer ($15-20)
- Add water if the mixture feels dry (should be damp like a wrung-out sponge)
- Cover with a black tarp to trap heat if temperatures aren’t reaching target
Troubleshooting low temperatures:
- Add more nitrogen materials (coffee grounds work well)
- Ensure proper moisture content—too dry or too wet will inhibit heating
- Check that your pile is large enough (minimum 3 cubic feet)
- Add a compost activator if temperatures still won’t rise
4. Age Compost Properly (minimum 18-24 months waiting period)
Even after hot composting, patience is essential. The compost needs extended aging to ensure complete pathogen breakdown.
Why the long wait? While hot composting kills most pathogens, some Toxoplasma oocysts may survive. Extended aging allows natural microbial processes to continue breaking down any remaining pathogens.
Storage during aging:
- Transfer processed compost to a dedicated aging bin
- Label with the start date to track aging time
- Cover to prevent recontamination from fresh cat waste
- Turn occasionally (once monthly) to ensure continued decomposition
Testing for safety: Some university extension offices offer testing services for finished compost, which can provide peace of mind before use.
Where Can You Use Composted Cat Litter? Safe vs. Risky Applications
Safe Uses That Benefit Your Garden
After proper composting and aging (minimum 18-24 months), you can safely use the finished compost in:
Flower Beds and Ornamental Gardens
Apply a 1-2 inch layer twice yearly around established ornamental plants. The compost improves soil structure and provides slow-release nutrients. This is particularly beneficial for flowering perennials and shrubs.Around Trees and Shrubs
Aged cat litter compost creates excellent moisture retention around woody plants. Apply in a 2-inch layer extending from 6 inches away from the trunk to the drip line. This application helps reduce water needs during dry periods.Lawn Top Dressing
When properly aged, a thin layer (maximum ¼ inch) can improve soil biology in lawns. Apply in early spring or fall, then water thoroughly to help it settle into the soil surface.
Never Use Composted Cat Litter On
Vegetable Gardens or Any Edible Crops
Even after extended composting, the risk of pathogen survival makes this use inadvisable. The potential health consequences aren’t worth the benefit.Herb Gardens
Even for non-culinary herbs, avoid using cat litter compost. Many herbs are handled frequently, creating unnecessary exposure risk.Children’s Play Areas or High-Traffic Zones
Areas where people frequently contact the soil directly should never receive cat litter compost, regardless of how well it’s been processed.
“I Composted My Cat’s Litter for a Year” – Sarah’s Success Story
Sarah, an apartment dweller in Portland with two cats, started composting their litter after calculating she was sending over 600 pounds of waste to landfills annually. “I was shocked by the numbers,” she explains. “It completely contradicted my other sustainability efforts.”
Using a balcony-friendly tumbler system, Sarah managed to reduce her cats’ waste output by 85% within the first year. The unexpected benefits surprised her: “The compost process actually controlled odors better than when I was just bagging the litter. And I saved about $120 on litter costs by switching to a compostable brand that required less frequent changing.”
Her creative solution for limited space was a stacked two-tumbler system mounted on a rolling platform, allowing her to move it to catch optimal sunlight on her small balcony. “The key was being consistent with turning it and monitoring the temperature,” she notes.
After 24 months of aging, Sarah had her compost tested through a local university extension service. The results confirmed it was pathogen-free, and she now uses it for her extensive balcony flower garden, which has thrived with the addition.
7 Common Questions About Composting Cat Litter
1. How long does it take for cat litter to fully compost?
The initial decomposition takes 30-45 days in a hot compost system, but you must age it for an additional 18-24 months before use to ensure pathogen destruction.
2. Can I add cat litter to my regular compost bin?
No. Always maintain a separate composting system for cat litter to prevent cross-contamination with kitchen scraps or materials destined for vegetable gardens.
3. Does composted cat litter smell bad?
Not if managed properly. A well-maintained hot compost system has minimal odor. If you notice strong smells, it likely indicates the compost needs more carbon material or better aeration.
4. What’s the difference between hot and cold composting for cat litter?
Hot composting (reaching 145°F+) is essential for cat litter as it kills pathogens. Cold composting (ambient temperature decomposition) won’t reach temperatures necessary to destroy Toxoplasma oocysts and other harmful organisms.
5. Is it worth composting cat litter if I only have one cat?
Absolutely. A single cat generates approximately 300+ pounds of litter waste annually. Even small-scale composting significantly reduces this environmental impact.
6. How do I know if my composted cat litter is safe to use?
Age it for the full recommended period (18-24 months minimum), ensure it went through proper hot composting phases, and consider laboratory testing through a local extension service if you have concerns.
7. What local regulations should I check before composting cat waste?
Some municipalities have specific regulations about pet waste management. Check with your local environmental agency, health department, or waste management service before establishing your system.
Start Composting Your Cat Litter: Next Steps for Success
Ready to transform your cat’s waste into a resource? Here’s your action plan:
Environmental impact: By composting one cat’s litter, you’ll divert over 300 pounds of waste from landfills yearly. That’s approximately 15,000 pounds over your cat’s lifetime!
First purchase recommendations:
- Swheat Scoop ($18-22): Most affordable wheat-based option with good clumping
- World’s Best Cat Litter ($25): Corn-based with excellent odor control
- Feline Pine ($15-18): Good budget option that breaks down quickly in compost
Free resources:
- Download our “Cat Litter Composting Tracker” to monitor temperatures and aging times
- Join the Small Green World newsletter for monthly composting tips
- Check our YouTube channel for step-by-step setup videos
Transition plan: Most cats need 7-10 days to adjust to new litter. Start by mixing 25% new compostable litter with 75% of your current litter, then gradually increase the ratio every few days until you’ve completely switched.
Expert Resources for Safe Pet Waste Management
Recommended reading:
- “The Pet Poo Pocket Guide” by Rose Seemann
- “Composting for Dummies” by Cathy Cromell (includes a section on pet waste)
- Cornell Waste Management Institute’s fact sheets on pathogen reduction
Online communities:
- The Sustainable Pet Owners Group on Facebook (15,000+ members)
- Reddit’s r/CompostingCommunity (search for cat litter threads)
Local workshops and resources:
- Master Gardener programs often offer composting workshops
- Many cities have urban sustainability centers with composting demonstrations
- Community gardens frequently host composting education days
University extension services:
- Penn State’s Agricultural Analytical Services Lab offers compost testing
- Oregon State University Extension provides free online composting courses
- University of Florida IFAS Extension offers soil and compost analysis
By following these guidelines, you can safely transform your cat’s waste from an environmental burden into a valuable resource. Remember that proper technique and patience are essential—this isn’t a process to rush or take shortcuts with. The reward is reducing your environmental impact while creating something beneficial for your non-edible garden areas.
Your hands were made for more than scooping litter—they were made for growing a more sustainable world, one compost bin at a time.