AlzChem Global

Calcium Cyanamide amateur gardeners

Is it advisable to use calcium cyanamide to fertilize potted plants?
Can calcium cyanamide be used to fertilize balcony boxes?

Calcium cyanamide is not recommended for potted plants and window and balcony boxes. The small root space and the intense rooting within the vessels carries the risk that the plants will absorb too much of the cyanamide directly, meaning before it is further decomposed, leading to brown leaf edges and root damage.

If you make the earth for the window and balcony boxes yourself, for example by mixing compost, earth and sand, then it is a good idea to mix calcium cyanamide into the substrate.
However, you should leave the substrate to rest for some time before using it.
Mix in evenly 1 to 2 kg of calcium cyanamide per cubic meter of earth. The earth should be slightly moist until it is used, (but not wet!), so that the bacteria can remain as active as possible. Mixing in calcium cyanamide counteracts harmful fungi, weed seeds and various pests in the soil.


Can calcium cyanamide be used to fertilize flowers?

Calcium cyanamide can be used for flowers if they are outdoor plants such as perennial beds with bulbous plants, dahlias or gladiolas. In these cases the cyanamide should be spread before budding or emergence. By contrast, annual flowers must be fertilized even before sowing or before planting, followed by a waiting period of one to two weeks.  Depending on the nitrogen requirement the amount to be applied is 30 to 50 grams of calcium cyanamide per square meter of bed area.


Can shrubs be fertilized with calcium cyanamide, without causing any damage?

Shrubs are relatively insensitive to calcium cyanamide because of their deep roots. Nevertheless, application in this case is a little more difficult, because most shrubs tend to bud strongly, and the young buds and leaves are naturally sensitive. Therefore it is best to spread the calcium cyanamide only in the interstices or to wash the leaves carefully using a watering can after application.  One major advantage of using calcium cyanamide on shrub beds: not only does it decimate the smaller seed weeds but it also impairs snail and slug breeding, for which perennial beds usually provide an ideal environment.


Can I fertilize raspberries with calcium cyanamide?

When fertilizing raspberry crops with calcium cyanamide the following instructions should be followed:

For full-surface fertilization the application rate should be about 30 grams per square meter. If fertilizing only the rows of plants the concentration in the planting row should not be more than 40 grams per square meter.  So it makes sense to carefully measure the area to be fertilized beforehand, and to precisely weigh or measure out the required amount of calcium cyanamide: the bulk density of calcium cyanamide is almost exactly 1, which means 10 kg calcium cyanamide have a volume of 10 liters.

Fertilization should be carried out in early spring before the new budding, when the raspberry rods are dry and therefore not immediately after dew or rain. 
However, the soil should still be moist if possible. This will to a certain extent enable a herbicidal side effect, and germinating weeds to be destroyed.
Earlier studies seem to indicate that the effect calcium cyanamide has on soil hygiene also considerably reduces infestation by the dreaded raspberry spur blight.


Can calcium cyanamide be used in the garden to combat clubroot?

It has been known for about 90 years now that calcium cyanamide helps to reduce infestations by clubroot. The pathogen that causes clubroot, Plasmodiophora brassicae, forms resting spores that can survive for up to 20 years in the soil.  These resting spores hatch flagellated zoospores that actively move toward the roots and penetrate the root hairs. This is where the first multiplication takes place. Subsequently the fungus penetrates the root cylinder, where it triggers the familiar growths (gall formation), leading to stunted growth or death of the plants.

What is known is that this disease is aided by frequent crop rotations, low pH levels in the soil, high temperatures and high soil moisture. By contrast, high pH values restrict the mobility of zoospores and reduce the risk of infection. Therefore even just the pH effect of applying burnt lime or calcium cyanamide will reduce infestation.
However, in the case of calcium cyanamide the fertilizer hinders the resting spores on germination for a certain time, and this therefore releases no zoospores.
This does not actually kill off the resting spores, but instead inhibits them for just a few weeks. This phase is enough in most cases to enable the brassicas to have a chance of building a powerful and healthy root system.


What can be done to save scorched lawns?

Whether the damaged lawn can recover depends on the degree of scorching. In any case, drought stress is to be avoided and the lawn should be kept evenly well moist. In most cases the grasses regenerate within a short time from the rootstock (such as after a severe winter). If there is no new growth after four weeks it can be assumed that the grasses can no longer recover, and that the lawn will need to be reseeded.


How much PERLKA should I use on the lawn?

20 to 25 grams per square meter of calcium cyanamide should be applied on lawns. 


What are the benefits of using calcium cyanamide for composting?

For many decades calcium cyanamide has been used with great success in composting. Numerous scientifically-verified trials have shown that calcium cyanamide accelerates composting like no other fertilizer does, increasing the rotting temperatures, promoting the breakdown of cellulose and promoting the development of valuable humic acids. It is also known, however, that calcium cyanamide decimates slugs and slug eggs, weed seeds and certain harmful fungi in the compost.


Are compost worms harmed by using calcium cyanamide?

Compost worms avoid the top layer of the compost heap, preferring to inhabit the middle layers, where the degradation of organic matter is already well advanced. When calcium cyanamide is used properly, meaning regular spreading onto the surface of the compost heap (when a layer of about 25 centimeters of fresh material has been added), there is no damage to the compost worms.


Will my shrubs and bushes be harmed by using calcium cyanamide?

Shrubs and bushes are very non-sensitive because they have deep root systems, provided the calcium cyanamide does not get onto the leaves. For this reason calcium cyanamide can be spread under shrubs and bushes without any problem, even at higher doses (up to 60 grams per square meter).

So smaller seed weeds can easily be prevented. However, like shrubs and bushes root weeds such as goutweed, wheatgrass or bindweed are likewise not sensitive, as they too are rooted very deeply and the cyanamide does not penetrate so far.  However, like shrubs and bushes bindweed is also not sensitive, as it too is rooted very deeply and the cyanamide does not penetrate so far. 
However, like shrubs and bushes bindweed is also not sensitive, as it too is rooted very deeply and the cyanamide does not penetrate so far.


How large are the PERLKA grains, and can I apply them using my spreader machine?

PERLKA calcium cyanamide is a relatively fine granulate, with the particle size ranging from 0.7 to 3.5 mm. Most of the granules are between 1-2 mm in size. In the small packages section of many garden centers you can buy a PERLKA fine screening of 0.7 to 1.8 mm. This size is better for spreader machines as the grain size does not vary so widely. If you wish to use a spreader machine to apply the calcium cyanamide you should in any case use the setting for a fine-grained fertilizer.


How can I check the application rate of my spreader machine?

There is an easy way to check the setting of the spreader machine: lay out a double-page spread of a newspaper onto a flat surface. The newspaper should then cover an area of approximately 80 x 57 cm, which is just under half a square meter. Then drive the fertilizer spreader twice over the open newspaper. The amount of fertilizer lying on the newspaper will then be approximately equal to the output quantity on one square meter (depending on the spreading width of the spreader machine). Fold up the newspaper carefully and trickle the fertilizer into an empty yogurt container, and weigh it on a letter scale. Since the bulk density of PERLKA calcium cyanamide is about 1, the amount may instead be measured in a measuring cup, milliliters will be equal to grams.


How much calcium cyanamide should be used in the compost?

Recommended use for adding calcium cyanamide to compost: when piling up the compost heap, use 150 grams of calcium cyanamide per square meter of surface area each time onto a layer of 25 centimeters of garden waste. Do not mix it in!


How does adding calcium cyanamide work for composting?

When calcium cyanamide is added to the top layer of a compost heap, meaning the fresh material, a high concentration of cyanamide develops within a short period, adversely affecting slugs and many germs and weed seeds that adhere to the plant material.  But after just about one week the cyanamide will have completely converted into urea or ammonium, and other non-toxic forms of nitrogen. Unlike conventional fertilizers, however, with calcium cyanamide the continued decomposition towards nitrate is greatly retarded.  This in turn benefits the microorganisms in the compost, which require the ammonium nitrogen to degrade the nitrogen-poor structural substances of the plant material. Therefore about a week after the calcium cyanamide is added there is almost an explosive multiplication of the rotting bacteria desired, resulting in a significant rise in temperature in larger compost heaps.  The strong shift in the microorganism population towards useful rotting bacteria along with the rise in temperature both have an additional hygiene effect on the compost.


Why can significant turf burns occur after applying calcium cyanamide?

There may be several reasons why a lawn exhibits turf burns after fertilizing with calcium cyanamide:

1. Overdosing: More than 30 grams of calcium cyanamide per square meter has been applied over a large area.

2. Uneven distribution: In this case the burns do not occur uniformly, but in strips or in clusters. If the calcium cyanamide has been applied with a spreader, strip-like burns may occur in the overlapping zones.

3. Spread on wet grass: In this case too many nitrogen granules stick to the blades of grass where they result in burns.

4. Spreading on a freshly-seeded lawn area: Until the grasses have a strong root system and tillers they are extremely sensitive to calcium cyanamide. So lawns should not be fertilized with calcium cyanamide in the year they are sown.