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can there vbe weed seed in horse manure

While it may be more nutritional, horse manure may also contain more weed seeds. For this reason, it is usually better to use composted horse manure in the garden. The heat produced from composting can effectively kill most of these seeds as well as any harmful bacteria that may be present.

Composted horse manure can also be used in the garden any time of the year. Simply toss it over the garden area and work it into the soil.

Is Horse Manure Good Fertilizer?

Fresh manure should not be used on plants, because it can burn their roots. However, well-aged manure, or that which has been allowed to dry over winter, can be worked into the soil without the worry of burning.

Horse manure is a good source of nutrients and a popular addition to many home gardens. Composting horse manure can help your compost pile become super charged. Let’s look at how to use horse manure as fertilizer and in the compost pile.

There is no set ideal time for how long to compost horse manure, but typically it takes two to three months if done properly. You are better off looking at the compost itself to see if it is ready. The horse manure compost will look like soil and will have lost its “manure” smell when ready.


At this point you could add a handful of nitrogen-rich granule fertiliser if you wish.

To do this, it’s recommended you create a compost pile that’s at least 2m across at its base. If you use some old netting to form a circle (and put your compost pile inside it), you’ll create a pile that has enough mass to keep up that critical temperature for the required time. Build up a layer of horse manure around 15cm deep, making sure it is damp but not wet (spray it with the hose if you think it’s too dry).

This means it will contain weed and pasture seeds that you don’t want growing in your garden. Hot composting horse manure should take of weed seeds but it needs to be a carefully controlled hot compost. Many home gardeners don’t get a true hot compost mix brewing and so some seeds may remain.


Horses may be responsible for spreading plants, many of which are considered weeds, over long distances, according to the findings of an Australian research project.

Results of the research showed that from a list of over 2,700 nonnative plants growing in Australia, seeds from many were able to grow from horse manure. Some of the plants were designated as noxious weeds, meaning that they were considered harmful to humans or animals in some way. The spread of some types of plants might or might not be a problem, depending on the particular characteristics and the location where they were introduced.

Many manure-borne seeds germinated well after passing through the digestive tract of a horse, and being deposited with manure meant that the seeds had a head start in growth because of the nutrients provided in the feces. Also, manure is often deposited in areas where the soil surface has been disturbed by the passage of horses, allowing seeds to take root in loose dirt.

Catherine Pickering, an associate professor at Griffith University in Queensland, led a study to identify the germination capabilities of various weed seeds found in horse manure. After reviewing literature on germination of manure-dispersed seeds in Europe, North America, Africa, Central America, and Australia, Pickering found that a high number of plants can be spread in this way.

Trail riding is a popular equestrian activity, and owners often transport their horses for long distances to engage in this recreational pastime. Pickering warned that legislators should consider the possible threat to agricultural activities and the environmental impact before opening parks and other public lands for equestrian use. Though some plants spread in horse manure are not inherently harmful, Pickering’s research found that 99% of the reviewed species were listed as weeds in at least one global location.