When do you start feeding?
One of the most important parts of germinating weed is feeding (watering or more).
It will depend on the growing medium you are using, but in most cases, you will not need to supply any nutrients for the first 2–3 weeks. There will be of plenty of nutrients available in the soil, and even coco will only need nutrients added after a week or so. If you do opt for coco or hydroponics, nutrients should be added at 0.25x their regular strength. Once the first set of leaves appear, increase this in increments of 0.25 per set of leaves. For beginners, we would always recommend using a soil medium. It allows you to get to know the intricacies of growing weed more efficiently and can be the least punishing if you make mistakes.
An easy way to spot if more nutrients are needed is to observe the leaves. The serrated leaves will start to turn pale green as nutrient stores are depleted. Left long enough, leaves will eventually turn yellow. This is a definite sign that more nutrients are needed. Your plant will not die if the leaves turn yellow, but it is a timely reminder to feed your young seedling.
Nitrogen is the most commonly needed nutrient during periods of high growth. Once the seedling has been fed, the colour of the leaves will return to normal. Depending on how long you waited to take action, this can take a few hours or a whole day.