A new method for me to stimulate soil life in the spring, and thereby also the Stinzenflora, is the use of what is called compost tea. The idea is that you create a concentrated culture of aerobic soil fungi and soil bacteria and dilute them somewhat before it can be sprayed over the plants and/or soil. The advantage of this method is that you can treat a large surface area without too much trouble with very little starting material and a limited amount of work. Especially for areas of a few thousand square meters, such as our site, this is quite feasible. The disadvantage is that some investments are needed in equipment. The question is, of course, whether the addition of these soil organisms to a soil, where many bacteria and fungi are present, can have a positive effect. Without a good experimental design, however, it is not possible to determine what the effect is in practice. Setting up a good test is difficult because you can treat a part in a homogeneous part of the garden and leaving the rest intreated. You can then see if, after some time, there is any difference between the treated and untreated part. Usually finding a suitable place will be difficult.
This method is reminiscent of the preparation 500 used in biodynamic agriculture. Here cow dung is placed in the horn of a cow, which is buried in the autumn in the topsoil of a field. In the spring the horn is excavated and the contents are added to 8 to 10 liters of water. The whole is stirred for one hour to the left and one hour to the right, whereby the intention is to create a vortex during stirring. Thereafter the content is sprayed over the ground before plant growth starts. So it is meant to simulate the growth. As we shall see, the preparation and the purpose is similar to that of the preparation of compost tea. The manure in the horn will be enriched with soil fungi and soil bacteria and other soil organisms in the winter when it was buried in the ground. By stirring the solution, these organisms are distributed over the total volume and there will be enough oxygen in the vessel.
In literature you can find all kinds of recipes for making compost tea. A nice book is Teaming with microbes, The Organic Gardener’s Guide to the Soil Food Web, by Jeff Lowenfels & Wayne Lewis. This book is also translated into Dutch and then has the title Het Bodemvoedselweb. The English edition is also available as an E-book.
I have chosen to first stimulate the growth of the fungi before the ‘tea’ is made. Based on the literature, I used about 500 grams of mature good quality compost and 8 tablespoons oatmeal. The oatmeal is intended as a substrate where the fungi, which are present in the compost, can grow well. Compost plus oatmeal must be moist, there should be no free water. All moisture should be absorbed by the compost and the oatmeal. The second time I made the tea, I first pre-soaked the oatmeal. The material then becomes tacky, which makes mixing through the compost more difficult. The disadvantage of this method is that clumps arise and that does not seem ideal. Perhaps it is best to first mix the dry oats through the compost and then moisten this mixture, similar as I did the first time.
This mixture must now be put away at 26/27 degrees for several days in the dark. The increased temperature can be obtained by purchasing a heat mat with a thermostat. I already bought the thermostat, the mat (15Watt) I had to buy. I put the compost plus oat material into an empty 20-liter bucket. The amount of compost is too small to spread evenly. A certain layer thickness is required to prevent dehydration and to use the temperature sensor of the thermostat. The bucket or bin must be airy covered because otherwise the case will dry out too quickly due to evaporation. I used a plastic garbage bag for this. This works well. If you go and see how it goes, there will be enough oxygen in the tank and in the compost during this process. A somewhat smaller plastic box or bin is probably better. The air humidity in the box may become even higher and the material can be distributed over the entire surface of the box. The size of the bin should roughly correspond to the size of the heat mat. It takes a few days before you can observe clear fungal growth. These are visible as white wires that run over the surface of the material. The fungal growth obtained was not yet excessive but clearly visible. This can be improved. The reason why the growth of the fungi is first stimulated, is because bacteria multiply faster than fungi. Perennials prefer a soil that is dominated by fungi. Annuals, on the other hand, prefer an environment dominated by bacteria.
After the fungi have developed well, about 20 liters of water can be added. Note that the water must not contain chlorine. Rainwater is of course ideal, but in the Netherlands most tap water is also fine. This vessel is then intensively aerated at room temperature for at least 24 hours. The aerating serves two purposes. Firstly, you want to ensure that there is always enough oxygen in the vessel, because you want to stimulate organisms that need oxygen to develop. Secondly, the goal is that the organisms spread well over the total volume and do not stay in a number of clumps. After that, the intention is to spray the content over the site. To prevent the nozzle from becoming clogged, it is advisable to sift the material afterwards. I used a simple kitchen sieve for this. There are also many other possible solutions. You can find everything about this on the internet. Often seaweed (Kelp) or other additives are used that stimulate the growth of bacteria. A waste product from sugar production, Molasses and especially ‘Blackstrap Molasse’ is highly recommended. I have done no further additions except the oatmeal so far.
For the aeration you need an air pump as used for aeration of ponds. It is stated that you must be able to pump at least 1 liter of air per minute, per liter of water. For a bucket of 20 liters that is at least 1200 liters per hour. There are air pumps that deliver this exactly. I have opted for a slightly more powerful pump of 1800 liters of air per hour. The price difference with that of 1200 liters was not big. This pump came standard with 4 spherical ‘air stones’, which you hang in the bucket and are meant to distribute the air. If the whole content of the bucket is bubbling vigorously, it’s okay. Of course, it is also possible to make a smaller volume of tea. If you want you can dilute this tea before it is ready for use. You need sufficient moisture to distribute it well over the terrain. I estimate that I have added about 1/3 extra water. Some users dilute 5 times. The more you dilute, the lower the input from the cultured soil organisms will be, with the same amount of moisture that you spray on the soil. The air pump should be positioned higher than the water level to prevent water recoil in the pump. I used the counter in the kitchen.
I had never used a garden sprinkler before. When we bought the house there was a simple pressure sprayer from Gardena with a capacity of 5 liters. I have thoroughly cleaned it before use. At the end of the hose there is a cap with which regulates the fineness of the sprinkler. The further this cap is tightened the finer is the spray and the sooner the nozzle will be blocked. I have tightened the cap so far that it is just not loose. You then get a good jet of water. This allows you to easily reach places that are further away from the path. At this time of the year there are so many Stinzenplants already above ground that you should avoid treading the surface where they grow. On January 26, I have been spraying tea for the first time. It did not freeze and was misty. Later we had some frost and snow. Perhaps it is wiser to do it at a time when most of the frost is behind us. It is also not recommended to spray in full sun. A grey humid day with a temperature above 9 degrees celsius seems most suitable. On the other hand, you want to apply it it at the beginning of the development of the aboveground parts of the bulbs, and you do not want to spray it too late. I sprayed freshly brewed tea again on February 14th. The tea has a short shelf life, so it must be used immediately after preparation.
Afterwards it is important to clean all used materials immediately. If you wait too long and it is caked up, you need aggressive means to clean the case and I would not recommend that.
Hopefully this activity contributes to an optimal growth and flowering of the Stinzenplants. At the moment nearly three weeks have passed since the first spraying. More snowdrops have come above the ground. Many seedlings of snowdrops , Winter Aconites and other Stinzenplants are now present. It is quite conceivable that it is precisely these young seedlings that benefit most from the spraying of compost tea so early in the year.
Of course there are many more factors at play and this method certainly is not a panacea. It is not difficult to do, once you have all the stuff in the house . I enjoyed doing it, and if it does beneficial it will not hurt either.