When weeds spread in the garden, good advice is needed. Horn meal is mentioned by many hobby gardeners as a solution for controlling weeds. Other experiences and expert opinions suggest that horn meal has been used with limited success and in a sensible way in the fight against unwanted weeds. But what about horny flour as a weed killer?
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Hornmehl – Definition
This is crushed or ground horn that comes from animal hooves and horns. It is a waste product from slaughtered animals whose hooves and horns are processed into horn meal/horn shavings. It is offered on the market primarily as a so-called secondary raw material fertilizer. It is available in gardening shops and in agricultural wholesale shops and often in slaughterhouses or on farms where hoofed animals and bovids are slaughtered.
Horn meal as a weed killer?
In general, the answer to the question is yes. Horn meal is rich in nitrogen. It therefore depends on which plants and which weeds tolerate a boost of nitrogen and which do not. For example, clover and moss are weeds that die in soil that is rich in nitrogen. However, hobby gardeners only get limited help if clover and moss have settled on plants or if they are in the immediate vicinity and are sensitive to nitrogen. This includes many flowering plants such as perennials. Nitrogen stimulates leaf growth, but at the same time robs a plant of the energy for flowering. Most green plants, on the other hand, tolerate nitrogen well, such as:
- lawn
- Rosen
- Salat
- Kohl
- Palm trees
- Dieffenbachie (Dieffenbachia seguine)
- Make it
- Boxwood (Buxus sempervirens)
- Tree of Life (Thuja)
- Nitrogen sensitive weeds
- Klee (Trifolium)
- Moos
- Ackerschachtelhalm (Equisetum arvense)
- Hungerblümchen (Draba verna)
- Wegerich (Plantago)
- Kamille (Matricaria chamomilla L.)
- Wicken (Vicia)
nitrogen-poor soil
These and a few more weeds thrive where the soil is low in nitrogen. When it comes to using horn shavings or meal to combat these weeds, only plant areas in the garden where there is a nitrogen deficiency, for example because insufficient nitrogen has been fertilized, come into question. Lawn, which grows weaker when there is a lack of nitrogen, reduces the lawn density and creates space for weeds, then offers optimal conditions.
Properties of horn shavings/meal
Horn shavings or flour contain other substances that make them an ideal fertilizer without affecting the pH value in the soil:
- Nitrogen: between ten and fourteen percent
- Phosphorus: between one and five percent
- Potassium: between zero and one percent
- Calcium: about six percent
- Sulfur: 0.008 percent
- Organic matter: 85 percent
- Duration of effect: between six and eight weeks
- pH-Wert: neutral
Difference between horn meal, horn shavings and horn meal
The ingredients are fully retained in all forms of shredding. The only difference is in the thickness of the individual particles, which is based on the different crushing methods.
Horn meal: Size up to a maximum of one millimeter Horn
meal: between one and five millimeters
Horn shavings: larger than five millimeters
application
Horn meal fertilizer should be used at the latest when the first unwanted weeds begin to spread. However, it is also suitable for reliably combating weeds that have spread over large areas. The following instructions describe how to proceed correctly with the gift and what to look out for:
- Dose: about 60 to 80 grams of horn shavings or flour per square meter
- It is best to apply early in the morning or in the evening after sunset (does not absorb well when the soil is warm)
- Alternatively: rake the soil, if possible, and work the horn residue into the soil
- Water areas well after application
- Keep the soil slightly moist (take into account the water requirements of/neighboring plants)
- Waiting time: at least seven days, sometimes a few weeks
- Not suitable for or in the immediate vicinity of young plants/freshly seeded lawns
Prevent re-growth of weeds
In order to prevent unwanted plants such as clover and moss from growing (again), it is advisable to add horn meal every three months from spring to late summer/autumn. It should be noted when the last time for fertilizing is before the onset of winter and the hibernation of the (neighboring) plants. Fertilizers should not be applied too late, as this would make it difficult for the plants to enter the winter phase and, in the worst case, could result in damage that could lead to death.
Kira Bellingham
I'm a homes writer and editor with more than 20 years' experience in publishing. I have worked across many titles, including Ideal Home and, of course, Homes & Gardens. My day job is as Chief Group Sub Editor across the homes and interiors titles in the group. This has given me broad experience in interiors advice on just about every subject. I'm obsessed with interiors and delighted to be part of the Homes & Gardens team.