is horse manure good for grass

Is Horse Manure Good for Grass? Exploring the Pros and Cons

As a gardener, you likely know that fertilizer provides essential nutrients that help grass and other plants thrive. But have you considered using horse manure as a natural fertilizer option?

Horse manure contains nitrogen, phosphorus potassium and other nutrients that grass needs. It also improves soil structure and helps retain moisture. However, fresh manure can burn grass roots if overapplied. And it may contain weed seeds or pathogens.

By understanding the benefits and potential drawbacks of using horse manure on grass, you can make an informed decision. We’ll explore the pros and cons in detail here.

The Potential Benefits of Using Horse Manure on Grass

First let’s look at some of the advantages of using horse manure as a fertilizer for lawns and pastures

1. Slow-release organic fertilizer – Horse manure breaks down over time, steadily releasing nitrogen, phosphorus, potassium and micronutrients. This provides a gentle feeding for steady grass growth rather than quick bursts.

2. Rich source of nutrients – Fresh horse manure contains good levels of nitrogen, phosphorus, potassium and micronutrients like iron, manganese, zinc and copper. These are all nutrients grasses need to thrive.

3. Improves soil structure – The organic matter in manure feeds beneficial soil organisms like earthworms and bacteria. Their activity improves drainage, aeration and moisture retention.

4. May suppress weeds – Applying a thick layer of manure as a mulch may inhibit weed seeds from sprouting. The mulch also blocks light that weeds need.

5. Prevents erosion – Spreading a thin layer of manure protects bare soil from erosion during heavy rain. The small particles fill in spaces between soil and grass plants.

6. Low cost – If you have access to a local stable, fresh horse manure is often free for the taking. This provides an inexpensive fertilizer option.

7. Good for grass establishment – Well-aged manure mixed into soil provides nutrients new grass seedlings need to develop deep roots and withstand stresses.

With proper application, these benefits of horse manure can improve the health, thickness and resilience of grass in lawns and pastures. But there are also some potential drawbacks to be aware of.

Potential Problems With Using Horse Manure on Grass

While horse manure offers benefits, it also comes with some risks and difficulties that are important to keep in mind:

1. High salt content – Horse urine and manure contains salts that can accumulate in soil over time. Excess salts burn grass roots and leaves.

2. Weed seeds – Manure mixed with bedding materials often contains viable weed seeds that can germinate and thrive.

3. Unpleasant odor – Fresh manure gives off an ammonia odor as it decomposes. This smelly process takes several months.

4. Pathogens – Horse manure may contain dangerous pathogens like E. coli, salmonella and parasites. These can survive in fresh manure.

5. Attracts flies – Flies are attracted to fresh manure and can become a nuisance. Stockpiling manure provides an ideal breeding ground.

6. Nitrogen imbalance – Too much fresh manure overloads soil with nitrogen, leading to excessive grass growth and disease susceptibility.

7. Nutrients not readily available – The nutrients in manure only become plant-available over an extended period as organic matter breaks down.

8. Application difficulties – Manure is bulky and heavy to transport and spread. It requires special equipment for large areas.

9. Timing issues – Manure should be applied in fall for benefits the next growing season. Quick greening is better achieved with commercial fertilizer.

With some planning and careful management, these potential issues can be avoided when using horse manure.

Best Practices for Using Horse Manure on Grass

Follow these guidelines to use horse manure as a fertilizer successfully and safely on your lawn or pasture:

• Test soil first – Check current nutrient levels to avoid over-fertilization. Also test salt content.

• Compost manure fully – Composting destroys weed seeds, pathogens and reduces odor. Takes 3-12 months.

• Apply in fall – Apply aged manure 2-3 months before grass starts growing in spring.

• Spread thinly – Apply no more than 1/4-1/2 inch layer raked into the soil surface.

• Limit frequency – Feed grass with manure only once every 2-3 years to prevent salt and nitrogen buildup.

• Mix with fertilizer – Add a small amount of nitrogen fertilizer to provide rapid greening while organic nutrients release slowly.

• Irrigate after applying – Water deeply to wash salts down through the soil profile away from grass roots.

• Monitor effects – Watch for signs of over-fertilization like excessive growth or scorched leaf tips.

With careful management, horse manure can be an economical organic fertilizer for grass. But patience is required to allow the slow-release nutrients to take effect. If you notice any problems, adjust your application rate or frequency.

What Type of Horse Manure is Best?

To maximize benefits and avoid issues, use well-aged or composted horse manure. Here is a comparison of manure types for grass:

• Composted – Best choice! Composting kills pathogens and weed seeds. Reduces odor. Nutrients are stabilized.

• Well-aged – Aged 6-12+ months. Lower odor, fewer viable seeds. Nutrients not readily available.

• Semi-fresh – Aged 3-6 months. Stronger odor, more seeds. Higher risk of burning grass.

• Green/fresh – Not recommended. Very strong odor, pathogens present, nitrogen overload risk.

The ideal horse manure for fertilizing grass should be aged or composted for at least 6 months up to 2 years before applying. This allows the organic matter and nutrients to stabilize.

Fresh manure straight from a horse stable is not well-suited for directly applying to grass. It requires aging first to reduce risks.

How to Compost Horse Manure

Composting horse manure results in an excellent organic fertilizer for grass free of concerns about weed seeds, odor or disease. Here are some tips for composting manure:

• Mix manure with carbon-rich materials like straw, leaves, wood chips or sawdust. This balances nutrients for more complete composting.

• Maintain a moisture level of 40-60% by watering occasionally. The pile should be damp but not soggy.

• Turn or stir the compost pile every 7-14 days to introduce oxygen needed by beneficial bacteria.

• Cover the pile with a tarp to retain heat and moisture. Place in partial shade.

• Monitor temperature. The internal temperature should reach 130-150 F indicating active composting.

• In 6-12 months, the pile will turn dark brown and soil-like when finished. Allow more time if needed.

Composting horse manure requires some work upfront, but yields an excellent slow-release organic fertilizer for grass.

When to Apply Horse Manure to Grass

Timing the application of horse manure is important to provide nutrients when grass needs them most while avoiding excess growth or burning:

• Spring – Not ideal, as cool soil delays breakdown, increasing burn risk. Best time for commercial fertilizer.

• Summer – Avoid, as heat speeds decomposition, risking nitrogen overload. Grass is also heat stressed.

• Fall – Best season, as microbes break down manure over winter. Nutrients available as grass resumes growth.

• Winter – Not recommended, as frost halts decomposition. Nutrients will leach away before grass is actively growing.

Ideally, apply aged horse manure in early fall, at least 2-3 months before the start of the active grass growing season. The nutrients will break down over winter and be available in spring.

How Much Horse Manure Per Square Foot of Grass?

A typical application rate is around 1/4-1/2 inch of composted manure spread over the grass surface. Some key considerations for application rate include:

• Soil needs – Account for current soil nutrient levels based on testing. Avoid over-fertilizing.

• Grass species – Fast-growing types like ryegrass may need more frequent applications at lower rates.

• Manure age – Well-aged manure may allow slightly higher rates versus fresh manure which has higher nitrogen.

• Grass use – Lawns used for pets or children’s play may better tolerate higher rates for traffic resistance.

A general guideline is to apply no more than 1/2 cubic yard of aged horse manure per 1000 sq ft of grass area. Adjust this rate based on the factors above. It’s also best to split applications over 2-3 years rather than fertilize annually.

Application Process for Horse Manure on Grass

Follow proper application techniques to avoid problems when using horse manure as fertilizer for your lawn or pasture:

• Mow grass – Cut the grass a few days before application so manure reaches the soil surface.

• Rake thoroughly – Break up any clumps and evenly distribute manure over the entire area.

• Spread thinly – Apply just a fine layer no more than 1/2 inch deep. Don’t form clumps or piles.

• Water lightly – Gently water to help wash manure nutrients into the soil without runoff.

• Allow time before mowing – Wait about one week after application before mowing to prevent clumping.

With the right timing, rate and technique, horse manure can provide an organic fertilizer boost while avoiding issues like odor, burning, weeds or disease. Pay close attention in the weeks after application and adjust your approach if needed. Over time, you can fine-tune an application regimen tailored to your grass type, climate and soil.

The Bottom Line – Horse Manure as Fertilizer for Grass

Horse manure can be an excellent organic fertilizer for lawns and pastures, providing slow-release nutrients, improving soil and helping grass thrive. But fresh manure poses some risks from odors, pathogens and weed seeds.

To maximize the benefits while avoiding problems, use well-composted or aged horse manure applied at the right time of year at moderate rates. With careful management, horse manure offers a time-tested organic fertilizer option for vibrant, healthy grass. Just be patient, as the effects will take time compared to commercial fertilizers but are longer lasting.