LST und Düngen ?

With LST, you shouldn't wait too long, because the stem gets too woody and bends over more easily. On the other hand, don't do it too early, or it won't do anything. Bending down the main stem is supposed to expose the nodes so that new shoots can grow upwards. So wait until you have three or four developed leaf pairs/nodes (cotyledons don't count).

Typically you would want to start using low doses of fertilizer in soil around week 3. Follow the manufacturer recommended feeding for your current week. Even though your plant is only taking up a small space. You should water enough to fully saturate the whole pot and not just where the plant is. This will help to roots spread out in search of water instead of staying in the same place. As far as LST, I like to start once my first two nodes are about 1”. I will pull my plant down and direct the the branches to wherever I want them to go to fill the canopy. I use plant stakes with a loop on the end and drive them right into the soil to hold the plant and branches down. Once it gets big enough I then tie down to the side of the pot. I hope this helps.

Hello, your soil should already be pre-fertilized. If not, you can start fertilizing lightly. A seed can usually manage without nutrients for up to 2 weeks. So when you need to fertilize depends on the soil you bought. But I think you can start lightly right away. Just remember that fixing a deficiency is easier than getting rid of an overdose. With the LST, you need to wait a bit. The root stem still needs to grow, and once it has 2-3 more branches, you should be able to start. If something breaks or bends, get some tape (most things can always be saved). LST can also be something like a fan that creates a light breeze, shaking the plant, or anything that doesn't really harm the plant. Hope that helps.