Among all plants grown on the earth exist plants that do not like manure. Many people, especially gardeners think that all vegetables, garden plants and flowers thrive when the soil in which they are grown is supplied with manure.
However, this is not true. Some plants burn when the soil is supplied with manure, making it unsuitable for them. This is called manure burn. The plants get scorched, particularly foliage and plant roots.
Other plants however flourish when fed with nutrients from manure, but unfortunately become harmful for human consumption as a result.
Manure and manure burn
Manure is simply organic matter that is made of animal waste and bedding straw. It comes in different forms, with the most common being compost manure and green manure.
Manure burn simply occurs due to excess application of fertilizer to wet plants. This applies in cases of surface and root vegetables. The following is a list of vegetables that do not like manure:
- Herbs
- Tomatoes
- Peppers
- Cucumbers
- Lettuce and other leafy green vegetables
- Carrots
- Potatoes
- Beetroot
- Radishes
- Parsnips
- Eggplant
- Cabbages
- Squash
- Celery
- Melons
Flowers and manure
There are also flowers that do not like manure. In actual fact, a majority of flowers do not like manure despite the fact that their roots become stronger once established.
We would expect that once their roots are established, they would not be adversely affected by a supply of manure. These include Roses, the most loved of all flowers.
Fruit and flower plants do not require manure for production of healthy fruits and flowers because the main and active mineral in manure is nitrogen. The work of nitrogen is to develop strong roots and leaves.
Horse manure for Roses
The only manure known to be good for roses is Horse manure. Horse manure is the waste or excrement horses release and which is used in gardens and farms as fertilizer.
It is usually mixed with top garden soil, causing a release of many nutrients such as nitrogen, which causes roses to grow and thrive.
Horse manure improves the structure of the soil, leading to excellent infiltration and retention of water in a rose garden or farm.
Vegetables and manure
Many vegetables do not like manure. This is because of manure burn caused by the presence of too much ammonia. Most nitrogen found in soil is carried by ammonia, the fastest chemical to leave manure.
This leaching makes the soil overly acidic and overfeeds the roots of plants. Apart from rabbit manure, almost all manures contain 15 to 20% ammonia.
In humid and hot climatic regions, most vegetables do not like manure mulch and manure feeds either, because the increased humidity and heat leads to leaf burns.
The nitrogen content in manure is usually too high for young vegetable plants to bear.
Root vegetables and manure
We have root and surface vegetables. Root vegetables grow downward towards soil nutrients and tend to produce better and tastier roots as a result.
Therefore when you plant them in soil enriched with manure or other fertilizers, the plants overfeed, resulting in underdeveloped roots and forking, such as is witnessed in carrots. This clearly indicates their dislike of manure.
Salt content in manures
Salt content in manures is crucial for most plants because high salt content in manure dehydrates plants.
Some plants dehydrate when fresh manure splashes on their foliage during rainfall seasons, causing them to develop white burns on their leaves.
Most manures from livestock farming contain 5 to 10% salt, making them unsuitable for use by plants. Foliage burn is therefore caused by excess ammonia and salt in fertilizers which over-acidify and dehydrate your plants.
Go for manures with low salt content for the sake of your plants. Some manures are hot while others are cold. Hot manures such as horse, cow, and sheep manure need time to decompose before use.
This causes them to work better and to become gentler to your plants. Cold manures such as chicken and rabbit manure do not cause any harm to plants, but help to feed the soil with higher nutrients which the plants need.
Indication of manure burn
Manure burn is also indicated by leaves with small brown patches or curled leaf edges without a distinct border between green and brown color.
To cure this, trim off the damaged leaves using clean scissors. This will allow your plants to recover from the burns.
Fixing of manure burn
To fix manure or fertilizer burn, flush out plants that have been damaged at the roots. However, if they are potted, water them until the water drains out at the base of the pots.
This helps to reduce the amount of nutrients in the soil. Wait until the soil is dry to the touch before resuming normal watering.