FAQs – Frequently Asked Questions for Sonnenerde

No.

It is a widespread myth that your plants produce more trichomes or otherwise benefit if you keep them in complete darkness for 24/48 hours before harvest. Ultimately, doing this is even counterproductive. The content of cannabinoids and terpenes in the cannabis plant is highest in the middle of the day and decreases with prolonged darkness. So, if you want the highest cannabinoid content and the most terpenes in your buds at harvest, you should harvest them during the light phase.

Yes. The final phase of flowering marks the onset of autumn for your plant. It takes little to no nutrients (especially nitrogen) from the soil and mainly pulls the nutrients needed to mature the buds from the leaves. Depending on the strain, your foliage can become quite colorful towards the end of flowering.

LST (Low Stress Training) and HST (High Stress Training) are ways to “train” your plants’ growth, meaning you can enforce a desired growth pattern to, for example, increase your yield or make optimal use of your cultivation space. The goal is almost always to break the plant’s apical dominance (the development of a strong main stem). Our organic hemp soil is basically suitable for any kind of training. You just need to keep in mind that depending on the intensity of the training, you should plan a correspondingly longer vegetative phase and adjust the pot size accordingly.

LST

As the name suggests, these techniques expose your plant to only moderate stress, with a lower risk of strong reactions compared to HST. You can bend and fix individual shoots downward (using clips, hollow string, ground hooks), thread shoots horizontally into a net stretched over the plants (screen of green), or imitate a summer storm by pinching shoots in the upper third with your thumb and forefinger and then bending them down 90° (supercropping).

HST

The name says it all: High Stress Training exposes your plant to high stress intentionally, with the same goals as LST. The most common HST methods are topping and fimming. In topping, you cleanly remove the main shoot, breaking apical dominance and promoting the growth of the next two shoots. Fimming originated almost by accident during topping. The new shoots are not cleanly removed but roughly halved, producing several (often up to six) new shoots. However, fimming is less controllable and the number of new shoots is unpredictable.

In the final stage, you can combine both techniques. For this, you should know your genetics well and have all other parameters close to optimal.

The light intensity your plant needs changes with each growth stage.

Basically, seedlings, clones, and mother plants require lower intensity, while the light demand increases during the vegetative phase and reaches its peak during flowering. In numbers (micromoles per square meter per second), if you have a PAR meter, you can use these approximate guidelines:

• Clones: around 200
• Seedlings: around 300
• Mother plants: up to 600
• Vegetative phase: up to 600
• Flowering phase: up to 1,000

If you don’t have such a device, you should follow the lamp manufacturer’s recommendations, which often specify the correct distance for their lamps. Too little light will cause plants to stretch and noticeably reduce yield, while too much light can cause issues like “burnt” leaves, ultimately inhibiting photosynthesis and nutrient uptake.

It is absolutely recommended to reuse our hemp soil Hanferde. The only thing you need to do is provide additional nutrients and minerals to the soil life between cycles.

To do this, you can remove the coarse roots from the previous cycle (known as ‘till’ cultivation, from the English word ‘till’ meaning to plough) and then mix your organic hemp soil with 10% by volume of our soil activator Bodenaktivator. This already contains activated biochar, rock dust and the right mix of microorganisms. In practice, mix 1 litre of Bodenktivator into 10 litres of used Bio Hanferde. For ease of handling, it is advisable to let the pot dry out for a few days after harvesting.

Alternatively, you can mix in organic compost (for example our Bio Kompost), rock dust, nitrogen sources such as horn shavings or chicken manure pellets, or other organic solid fertilisers. Adding, for example, 5 g/l of horn shavings should be sufficient to meet the plant’s nitrogen requirements for the next growth cycle. You can add the roots to your compost, if you have some, or chop them up and mix them back into the growing medium.

Alternatively, you can leave the roots in the soil and let microbial life break them down directly (“no-till” cultivation). For this, you only work organic material and minerals into the surface and let mulch or cover crops do the rest. This method is especially recommended for very large pots or raised beds.

A mulch layer (1–3 cm thick) is absolutely recommended for several reasons. First, it protects your soil from drying out too quickly by preventing water from simply evaporating. Second, the mulch material supplies nutrients for the microbial life in your soil. For example, our Bio Faser mainly consists of stable straw from dried organic cattle manure and is a perfect long-term nitrogen source for large pots or raised beds.

You can also incorporate all plant waste into your mulch layer. The use of so-called “cover crops,” meaning ground-covering plants, is practiced in living soil cultivation and is also hotly debated (especially indoors).

Advantages of sowing a cover crop like clover include: the soil is naturally covered, and the withered ground cover becomes part of the living soil again. Some ground covers, such as most clover species, are legumes that can fix nitrogen from the air and make it available in the soil, keeping the bed lush and green.

However, there are also disadvantages that should not be overlooked. For one, you shouldn’t use too many different or labor-intensive plants—the cover crop shouldn’t require more work than the main crop. Also, depending on where you live, cover crops may attract or introduce pests and diseases, which can be problematic.

Especially in indoor cultivation with limited space (as often in grow tents), you’ll have to perform some gardening interventions for several reasons. One reason is rising room humidity. While seedlings, clones, and plants in the vegetative phase prefer relatively high humidity (60%+), the risk of mold increases as flowering progresses. At the same time, humidity inevitably rises with increasing biomass. If you notice your humidity getting out of control and your tent looks like a jungle, you should remove some fan leaves and weak or mutually obstructing shoots. This will definitely reduce humidity by a few percentage points.

Another reason to remove leaves and shoots is to ensure even light distribution over all branches. Your goal is a flat, closed canopy from which similarly sized shoots and flower clusters grow. Therefore, you should regularly remove wilted fan leaves or those shading lower shoots. Also, remove shoots that clearly lag behind others so the plant can focus energy on the large buds and you harvest fewer “popcorn” buds. There are other cultivation reasons to remove leaves or shoots, but those relate to another question (What is LST/HST).

You can simply use the removed leaves and shoots as mulch, and the nutrients they contain will gradually be returned to your hemp soil.

It is recommended to start seeds in small seedling pots (up to about 0.5L) filled with designated Bio Anzuchterde. Place the seed in a hole in the soil just slightly larger than the seed itself, cover it with the organic seedling soil, and keep the substrate moist—but not soaking wet—and warm at about 25-26°C. (Of course, you can also germinate your seeds in paper towels, tissues, unbleached coffee filters, or similar, and then plant them in the Bio Anzuchterde if that method has worked well for you so far.)

After germination, it can take up to two weeks (depending on pot size) for the seedling container to become well-rooted. Once that happens, you can transplant the young plant into its final pot. Frequent transplanting is unnecessary and carries the risk of damaging the plant.

Rooted cuttings, whether Eazy Plug or organic potting soil, should be planted directly into the final pot with, for example, Bio Hanferde.

An exception often involves so-called autoflower strains. These cannabis varieties contain ruderalis genetics, meaning they are not photoperiod-dependent (flowering triggered by 12 hours of light), but automatically start flowering after a set time from germination. These plants often react sensitively to transplanting and should ideally be sown directly into their final pots. You can place some Bio Anzuchterde in the center of the pot and plant the seed there.

If you still want to transplant your autoflowers, experience suggests doing so within the first 14 days after germination.

As a general rule for growing in living soil: the bigger the pot, the better. The more substrate available, the more organic matter and soil life there is to supply your plant with nutrients.

Optimal is more than 20 liters of soil per plant; the minimum should be 15 liters. Especially if you plan long vegetative periods and extensive LST/HST training, choose the largest pot possible.

As an alternative to pots, you can also use a raised bed and grow several plants in it. For this option, automatic watering and moisture monitoring with a tensiometer are highly recommended.

Of course, you can also use our Bio Hanferde in smaller pots. Just keep in mind that smaller pots mean fewer roots, less organic material, and less soil life, so you can’t expect the same results as in larger containers.

There are various ways to water your plants and check whether the moisture level in the substrate is correct.

The best-known method of watering is undoubtedly the classic watering from above with a watering can. It is important to maintain a certain regularity from the outset. At the latest a few days (2-4 days, depending on the pot size) after repotting into the final pot (link to repotting), you should water daily.

Make sure that the root ball is dry and the pot is well rooted before repotting.

When repotting (after the plant is in the final pot and the surface is covered with mulch), water (slowly, in circular movements, not in a torrent) with approx. 15% of the pot volume and then stop watering for two to four days.

You should then start watering daily (in the morning, immediately after the lights come on), gradually increasing the amount of water from a few hundred millilitres a day as the plants grow, right up until the peak of the flowering phase. Please also note that evaporation will be greater in fabric pots than in plastic pots, and that a dehumidifier, if running, will exacerbate this effect.

A layer of mulch, e.g. from our Bio Faser, helps you to distribute the water evenly in the pot, protect the surface from drying out, reduce evaporation and prevent the perlite from floating.

Observe the saucers under your pots for the first 30 minutes after watering. If there is water in the saucers after this time, you should reduce the amount of water you use.

Waterlogging must be avoided at all costs, as the roots of your plants need oxygen to grow.

Depending on the pot size you have chosen (see What pot size should I use in combination with the hemp soil?), you may also want to consider an automatic watering system, e.g. in the form of drip blumat, wick irrigation, drip hose, drippers, autopot-system, eurobox-system or similar. This has the advantage that the moisture level in the substrate, once preset, is maintained throughout the entire cycle and you do not have to worry about overwatering or drought stress.

Both newcomers and experienced gardeners are advised to use a tensiometer to get a feel for the moisture content of the substrate and avoid mistakes when watering. A tensiometer also makes it much easier to adjust an automatic watering system.

They are available in analogue and digital versions from various manufacturers and are relatively easy to use.

Our organic hemp soil Bio Hanferde (like all our soils) contains all the nutrients and trace elements your plant needs for its entire life cycle until harvest. The high diversity of fungi, bacteria and other microorganisms ensures that your plant always has the right amount of nutrients available. All you need to do is water your plant(s). There is no need to add calcium and/or magnesium, as is currently often requested, because Bio Hanferde contains all the micro and macronutrients that the plant needs (regardless of the light source).

To further increase the biodiversity in your hemp soil, you can repeatedly make and water compost teas, as these cause microbial life to multiply in a very short time.

If you want to use your hemp soil permanently, you should ‘feed’ the soil life between cycles with organic material (Bio Faser, Bio Kompost) and minerals in the form of rock flour. Alternatively, you can use our Bodenaktivator to refresh your used organic hemp soil for the next cycle. See also How can I reuse the hemp soil?

Cultivation in living soil is fully organic growing within an intact soil ecosystem without the use of chemical additives.

Fungi (e.g., various mycorrhizae, Trichoderma), bacteria, insects, and microorganisms living in the soil supply the plant with nutrients from the organic matter present (for example, fungi gradually break down the nitrogen contained in horn shavings). This often happens through symbiosis, where the plant provides sugars produced during photosynthesis in return. High biodiversity, like what you find in our hemp soil, is the most important foundation for successful living soil cultivation.

Like all our soils, Bio Hanferde is a ready-to-use soil designed for immediate use. Activation in the sense of enriching it with nutrients and microbiology, as well as in the sense of maturation, takes place during composting at our site. Plants can therefore be planted directly into Bio Hanferde.

The basis of all our special soils is our organic compost, which is produced in a hot composting process. During this process, temperatures of 60°C and above are reached for several days, which makes it almost impossible for mycorrhizal fungi to survive.

In contrast, Bio Hanferde contains a large number of decomposing fungi and microorganisms. Adding mycorrhiza to the final pot and/or as an additive to the potting soil is highly recommended, but not necessary.

In the case of permanent use in beds/raised beds, it can also be assumed that, over time, natural colonisation with mycorrhiza from the surrounding area will take place.

Perlite floating can be easily prevented by applying a layer of organic mulch (e.g. Bio Faser) before the initial watering.

Perlite is an expanded mineral – in other words, a pure natural product that 'pops' like popcorn when exposed to high heat, thereby greatly increasing its surface area.

Perlite adds a lot of air to the substrate, making it lighter and increasing the scope for watering. This means that you can water too much without the risk of the soil becoming waterlogged.

The best time to sand the lawn is in spring or autumn, when the grass is actively growing. After mowing and scarifying, the material should be spread thinly and worked into the soil lightly. Our lawn Renovation soil is ideal for this, as it contains valuable organic matter as well as sand.

At Sonnenerde, we do not sell seeds or plants. You can buy or order these from selected shops. However, every year on 1 May, Sonnenerde holds an open day from 12:00 noon. A rare plant market is also set up here, where you can buy many old varieties from the individual exhibitors. This takes place exclusively on 1 May, directly on the Sonnenerde premises from 12:00 to 18:00.

You can get great organic seeds from Deaflora, or from Arche Noah Saatgut (Schiltern). You can also often find what you’re looking for at various plant markets! 

On the one hand, our organic hemp soil Hanferde has been specially formulated in terms of nutrient content and structure for growing cannabis; on the other hand, the addition of biochar gives it the so-called Terra Preta effect. It is, if you like, a Terra Preta for the pot. See also: What effect does biochar have in Sonnenerde products? As our organic potting soil Bio Blumenerde and organic tomato and vegetable soil Bio Tomaten- und Gemüseerde are very nutrient-rich, they will likely suffice for one growing cycle. However, due to the absence of biochar and other structural materials, they are less suitable for long-term use.

Biochar creates the Terra Preta effect. It provides a habitat for microorganisms and acts as a reservoir for water and nutrients. It absorbs nutrients and water like a sponge and releases them as needed, much like an open fridge from which the plants can take what they need. Thanks to the buffering effect of the biochar, over-fertilisation when replenishing the soil is virtually impossible. Our biochar is included in the following Sonnenerde products: our Terra Preta Schwarzerde, our Terra Preta soil concentrate Schwarzerde Konzentrat, our hemp soil Hanferde, our soil activator Bodenaktivator, our compost activator Kompostaktivator, our urban tree fine substrate Stadtbaum Feinsubstrat, our urban tree concentrate Stadtbaum Konzentrat.

Our organic hemp soil Hanferde is already being used successfully in pots at various CSCs and is recycled, for example, with our soil activator Bodenaktivator. This is where the minimum pot size of 15 litres that we recommend has proven its worth. However, most clubs currently opt for 20-litre pots; see also What pot size should I use in combination with your Hanferde?.

Our Terra Preta Schwarzerde is also already being used for cultivation in raised beds. This can optionally be combined with our Hanferde in bottomless pots.

In both cases, the use of an organic mulch layer, e.g. our organic fibre Bio Faser, is essential. See also: Why should I mulch every soil?

The first signs of overwatering are hanging/limp leaves. Over time, the plant becomes lighter in colour overall and its growth slows down, which is often mistaken for a lack of nutrients in the soil. Brown, necrotic patches may then appear on the leaves, as nutrient uptake is now permanently interrupted. In cases of permanent overwatering/waterlogging, the soil begins to smell musty and root rot may occur.

To prevent overwatering or waterlogging, it is recommended to use a tensiometer, especially at the beginning. As a general rule when watering, the maxim ‘less is more’ applies. Keep an eye for drainage in the tray and, if you see any, reduce the amount of water you use the next time you water. Depending on your setup, automatic watering systems can be used. See also: How do I water my plants in your Hanferde?

Our Terra Preta Schwarzerde can be used in both field beds and raised beds. To ensure long-term fertility for all crops, we recommend a layer thickness of 20–30 cm combined with a permanent layer of mulch. Almost any organic material can be used as mulch, e.g. grass clippings, wood chips or our organic fiber Bio Faser.

When used in raised beds, the lower section can be filled with existing soil or our organic raised bed soil Bio Hochbeeterde. Layering, as practised in hugelkultur, is not recommended here, as this would simply require regular top-ups of Schwarzerde. As a general rule, the soil ecosystem should be disturbed as little as possible by digging (no till).

Our Terra Preta Schwarzerde was developed over many years of trials, modelled on the original Terra Preta, in collaboration with numerous recognised institutions and scientists. The reason for its long-lasting fertility, when used correctly (see also How do I use your Terra Preta Schwarzerde correctly?), lies in the soil’s special composition and its extremely diverse microbiology. This combination creates a self-sustaining soil system which, when combined with a permanent organic mulch layer (e.g. our organic fiber Bio Faser), becomes even more fertile over the years.