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 your hemp soil. The only thing you need to do is provide additional nutrients and minerals to the soil life between cycles.

You can remove the roots from the previous cycle (known as “till” cultivation, from the English word “till” meaning to plow) and then enrich your organic hemp soil with organic material and minerals (10 vol% of our soil activator, which already contains activated biochar, rock dust, and the right microbiology). Alternatively, you can mix in organic compost, primary rock dust, or other organic fertilizers.

You can add the roots to your compost if you have one, or chop them up and mix them back into the substrate. 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 hemp soil from drying out too quickly by preventing water from simply evaporating. Second, the mulch material supplies nutrients for the microbial life in your hemp soil. For example, our organic fiber 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 organic seedling soil. 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 organic seedling soil 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.

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 organic seedling soil 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.

Alternatively, you can use a raised bed and grow several plants in it. In this case, it can make sense to use our organic terra preta soil instead of the hemp soil. For this option, automatic irrigation and moisture monitoring with a tensiometer are highly recommended.

Of course, you can also use our hemp soil 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 if the substrate moisture is right.

The most common method is traditional top watering with a watering can. It’s important to maintain some regularity from the start. From about 2–4 days after transplanting into the final pot (depending on pot size), you should ideally water daily.

Make sure the root ball is dry and well-rooted in the pot before transplanting.

At transplanting (once the plant is in the final pot and the surface is mulched), water slowly in circular motions—not in bursts—with about 15% of the pot volume, then pause watering for 2 to 4 days.

After that, begin daily watering (in the morning, right after lights on) and gradually increase from a few hundred milliliters to about 1.5–2 liters per day during peak flowering. Some strains (e.g., landraces from dry mountain areas) may be less thirsty, but if everything went well in the vegetative phase, your plants will use that amount daily. Note that evaporation is higher in fabric pots than plastic ones, and a running dehumidifier can increase this effect.

A mulch layer, for example our organic fiber, helps distribute water evenly in the pot, protects the surface from drying out, and reduces evaporation.

Watch the trays under your pots for about 30 minutes after watering. If water remains in the trays after that time, reduce the watering volume.

Avoid waterlogging at all costs, as roots need oxygen to grow.

Depending on your pot size (see “What pot size…”), automatic irrigation systems like drip emitters, wick irrigation, drip hoses, or similar can be considered. These keep substrate moisture steady throughout the cycle and prevent overwatering or drought stress.

For both beginners and experienced growers, using a tensiometer is recommended to gauge substrate moisture and avoid watering mistakes. Automatic systems are also easier to set up with a tensiometer.

Tensiometers come in analog and digital versions from various manufacturers and are fairly easy to use.

Our hemp soil (like all our soils) contains all the necessary nutrients and trace elements your plant needs for its entire life cycle until harvest. Thanks to the high diversity of fungi, bacteria, and other microorganisms, your plant always gets the right amount of nutrients. All you need to do is provide water. Additional calcium and/or magnesium, which is often asked about, is not necessary because the hemp soil already contains all micro- and macronutrients the plant needs, regardless of the light source.

To further increase biodiversity in your hemp soil, you can regularly make and apply compost teas, which multiply microbial life quickly.

If you want to reuse your hemp soil long-term (see “Can I reuse hemp soil?”), you should “feed” the soil life between cycles with organic material (organic fiber, organic compost) and minerals in the form of rock dust. Alternatively, you can use our soil activator to refresh your used organic hemp soil for the next cycle.

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.