Weed plants have not evolved to produce as many buds as possible indoors under artificial light. As a grower you will have to lend a hand with that. One of the most effective basic techniques that you can use for this is thieves, and that’s how it works.

In CNNBS basics, we cover a number of effective basic growing techniques that you can use to grow more and better weed. One of those basic skills is the thieving of weed plants, where you sacrifice small buds for the benefit of the top buds. You will therefore harvest fewer small tops, but the total harvest weight will be greater.

Why pruning work
In particular, pruning makes a lot of sense in growing weed indoors. This is mainly due to the way in which artificial light shines on the plants from above in a growing room. The dense foliage covers a lot of light and the lower branches and leaves grow largely in the shade. The tops of these lower-growing branches will therefore not develop well and provide little weed and a lot of cutting. By pruning them away at the right time, the plant can use its energy for buds that do have potential.

For thieves, the knife literally cuts on two sides; on the one hand, it saves an enormous amount of cutting during harvesting and on the other, it improves the quality and quantity of the rest of the tops.

The ideal moment for thieves
The top buds are the most important thing for a weed plant. Logical, because the upper tops catch more light and wind and therefore have the greatest chance of catching pollen grains from male weed plants and producing new seeds. As a result, the top buds of weed plants will always develop the best and therefore also become the largest.

Now indoor growers usually do not want to have their buds fertilized by pollen, but rather to make them as large and heavy as possible. The small tops that grow in the shade of the foliage all use a lot of energy and do not produce much weed and can therefore be removed better. But when will you remove them?

To properly estimate which tops use more energy than they contribute to yield, you have to wait until you can see whether or not they will reach the foliage. However, you should not wait until they already start to form flowers, because then they already ‘steal’ precious energy from the head tops, hence the word thieves. The best time for thieves is about two weeks after you have set the light schedule on 12/12 . The plant will not grow much after that, so you can see at that moment which buds will and will not reach the foliage.

What do you take away?
Exactly how much you have to remove from the thieves depends on the density of the foliage and the grow lamp used. For example, an HPS or an LED grow light penetrates deeper into the foliage than an energy saving light, T-neon or other fluorescent grow light. In addition, a sativa or a sativa-dominant type of weed generally has a more open structure than an indica, so that the light can penetrate deeper into the crop.

So you have to make a good estimate yourself which buds still catch enough light and which don’t. We recommend that you first carefully thunder from below to get a good feel for the technique. By not thieving a few plants at all you can clearly see the difference.

Rigorous vs. careful thieves
There are roughly two ways of thieving a weed plant; rigorous from above or careful from below. For the rigorous way, choose a place on the trunk and work from top to bottom. Count three to five nodes from the top growing point of each branch and prune all leaves and side branches below. Use scissors or a sharp razor or scalpel and cut as close to the trunk as possible.

If you prefer to be a bit more careful, you should start with thieves from below. First start by removing all the lower branches that did not reach the foliage. Next, make the lower third of the plant completely bare and free of leaves and side branches. Some growers leave the bracts on the thieves on purpose and only remove the side shoots. The bracts can still serve as food reserves for the plant.