Can You Plant Directly Into Well Rotted Manure? (I Asked 100 Gardeners)

It’s awesome.

Well-rotted manure can work wonders for your plant.

But you cannot plant directly into well rotted manure because it’s too rich, does not retain enough water, and is too unstable for healthy root formation. Manure provides some nutrients but is no substitute for soil which also contains inorganic compounds, air, and water that plants need.

In this post, I’ll help you understand if you can plant directly in different manure such as horse manure, cow manure, and chicken manure. I’ll also help you know if you can plant seeds in well-rotted manure.

Let’s begin.

Can you plant directly into composted horse manure?

You cannot plant directly into composted horse manure because your plants won’t be strong and healthy and are more likely to die. It is better to mix it with the soil because the manure does not retain water as well as the soil does.

Horse manure makes excellent compost material, but it takes at least six months before you can use it. Horse manure contains nitrogen, phosphorus, and potassium, chemicals that all gardeners will recognize instantly as the NPK formula, printed on many of the fertilizer bags you see in the nursery.

You can also spread it over the surface of an already planted garden bed, and the microbes and bugs that live in the soil will ensure that it is absorbed.

I asked 100 fellow gardeners if they have planted into well-rotted manure instead of soil. 79.7% said they don’t as it can harm their plants. But there were 20.3% that did try it out. It worked for some and caused problems for others.

Can you plant directly into composted cow manure?

You cannot plant directly into composted cow manure alone as it is not stable enough for solid root formation and dries out quickly. If your cow manure is scattered on top of the soil, you should plant it into the soil itself rather than just the upper layer of manure.

Fresh cow manure contains high levels of ammonia and salt that can burn plants, so it has to be well rotted. Manure should not make direct contact with the plant.

Cow manure is one of the best ways to provide bulk organic material to a garden because it helps condition the soil and provides nutrients and trace elements. However, it is better to mix the manure into the topsoil rather than planting directly into it because it will burn the plant.

I dumped 3 bags of composted cow manure along native soil behind my retaining wall. I stuck some sunflower and salvia seeds in it. They grew like wildfire, and had no issue. – John

Can you plant directly into composted chicken manure?

You cannot plant directly into composted chicken manure because it has high levels of nitrogen that will burn the plant roots. It is better to choose the safer route and mix it well into the soil before planting. Manure is essentially food, and plants like to live in soil, not their food.

It has a higher NPK content than horse manure and cow manure and must be very well composted before use. Its higher nitrogen content can be too much for root vegetables in particular which grow out deformed, so you should only add it in small quantities.

That said, well-aged chicken manure is highly beneficial for plants, and its higher NPK levels are perfect for fruiting vegetables.

I did so accidentally last year in an incredibly dumb move by not understanding the product I bought. My poor hydrangea was planted in pure manure for several months before I realized what I did and rectified. Until I fixed it, the plant was having all sorts of issues. – Cindy

Can you plant seeds in well-rotted manure?

You cannot plant seeds in well-rotted manure because even though they germinate, they will die soon. The high nitrogen levels will burn their delicate roots and shoots.

Also, the manure is unlikely to retain sufficient moisture long enough for seeds to germinate. Manure is too light to support strong root growth, and it can shrink very quickly in a pot or planter because it compacts too easily.

Too much manure of any kind can kill a plant because the NPK concentrations are not sufficiently diluted by the other elements contained in the soil.

Can I use manure instead of potting soil?

You cannot use manure instead of potting soil because the plants will not get a stable, well-balanced substrate to form strong roots. Manure, no matter how well-rotted, is no substitute for soil. There are nutrients in potting soil not present in the manure, so it can’t provide a balanced plant diet on its own.

Also, composted manure is lighter than soil and will eventually settle much lower in a planter leading to loss of substrate at the base of the plant and around the roots.

Manure is a very loose, aerated material that does not retain water well. Most plants need a bit of time in contact with the water to absorb it properly, so if the water drains off too quickly, they will end up dehydrated.

Do plants grow faster in manure?

Plants grow faster in manure when it is mixed with soil. Manure provides nutrients that plants need, which may be lacking in the soil itself. It can also improve drainage or water retention depending on the soil type, ensuring that the plants obtain a sufficient water supply but at the same time don’t get root rot.

Because manure improves nutrient levels, it can make plants grow faster. However, well-rotted manure is too rich on its own, and high levels in the soil can cause fast but weak growth, making plants leggy. Indoor gardeners are well aware that you can kill a plant by overfeeding it.

If mixed into the soil, well-rotted manure can stimulate growth and provide nutrients that may be lacking, but you should always be judicious about how much manure you add. Adding compost to soil improves drainage in heavy clay soil and helps water retention in sandy soil.

Manure is a compost. It is added to soil to amend it. I use manure when I recharge potting soil for the next season. – Judi

When does well-rotted manure become soil?

Well-rotted manure does not strictly speaking ever become soil. Soil contains minerals, trace elements, and inorganic material that manure does not. If left for a very long period, it can resemble soil in texture, but it is still not soil.

Soil consists of inorganic compounds as well as specific ratios of water and air that are not present in compost.

Forty-five percent of typical soils consist of minerals, twenty to thirty percent is water, and another twenty to thirty percent is air. Only five percent of most soils consist of organic material. By contrast, well-rotted manure consists almost entirely of organic plant material.

Well-rotted manure will eventually become absorbed into the soil and form part of it, but it cannot become soil itself.

How long does manure need to sit before planting?

The composting process for cow manure can take up to six months, depending on the climate, temperature, and moisture levels. Horse manure can take around four to six weeks if you tend it properly, but if not, it should also be left for six months. Chicken manure should be left for six to twelve months.

If you are prepared to put in some time and effort by turning the manure often to aerate it, adding a bit of water now and then, and some dry carbon in the form of straw, dried leaves, or shredded bark, you can speed up the decomposition process. The size of your manure pile will also affect the time it takes to rot as smaller piles decompose faster than big ones.

Decay takes place faster in warm temperatures than in cold ones.