Topping weed plants: a guide for beginners
Topping is a tried-and-tested growing technique to get more buds on one cannabis plant grown from weed seeds. Pruning a branch or main trunk allows you to double the number of growing tops, with the added bonus of the fact that your cannabis plant grows more in width than in height. The difficulty is knowing where and when to top a weed plant as these have major influences on the result.
Topping as a growing technique is believed to be thousands of years old and is used with all kinds of plants, such as the buxus (also know as 'box') - the tree that is commonly grown as nice thick hedges in gardens. To allow such a hedge to grow closer together, it is pruned once or twice a year. For every branch that is cut off, at least two new ones are substituted. The box becomes larger and denser and forms a dense hedge that you cannot see through.
Although topping weed plants has a completely different purpose, exactly the same thing happens. Every time you cut a branch or main stem, the side shoots underneath have the chance to take over. One branch turns into two branches, and two branches similarly grow into two bud sites, doubling the potential harvest. Instead of all energy going to one branch or top, the juices and the vigor are distributed evenly over the side shoots. Your marijuana plant becomes wider instead of taller.
Why topping is an essential part of cannabis cultivation
Topping marijuana plants is ultimately done for two purposes. Firstly, two tops yield more harvest than one. Although the two new bud sites will be smaller than the original ones could have become, their total weight is higher.
Topping gives the cannabis plant a better shape, as lower branches stretch out horizontally, making it easier to catch all the light needed (better light distribution is the key with this training method). This lateral growth helps achieve a higher harvest weight. Increasing yields is the main reason why cannabis growers top their weed plants.
Limiting height and more width development is the second important reason to top a cannabis plant. You can imagine that two branches will also grow less quickly than one. By topping cannabis plants, the growth is spread over several tops.
As a result, the weed plant develops more in width and less quickly in height. This is very useful when growing weed indoors, in a grow tent or a cupboard with a limited height.
What are the best strains for topping?
Even though many strains allow topping, not all cannabis strains are as susceptible to this training method. The following cannabis plant strain are very suitable to the training method topping:
When should you start topping cannabis plants?
It's not as simple as just taking a pair of pruning shears to your marijuana plants; there must be enough side branches to form new, and more bud sites. If you were to top cannabis plants, still in their seedling stage, before three to four sets of side shoots (nodes) grow well, you would do more harm than good. Young cannabis plants tend to need too much recovery time for this
Instead, you should wait at least until a weed plant is large and healthy enough and has a well-developed, healthy root system. Then the topping has the least (negative) impact on the plant's growth, and it hardly needs any recovery time.
There are roughly two ways to top, but remember that when you are topping cannabis plants, the plants in question must always have at least three nodes before you start.
What should you take away when you top a cannabis plant?
How much you remove at the top, or how far you prune the cannabis plant, depends on the purpose of the topping. If the goal is simply to create two peaks where one first grew, then it is best to remove as little as possible from the top growing point. Wait until the plant has about four nodes, and carefully cut out only the top growing point. This results in a rapid recovery and doubles the number of growth points.
Many growers, however, prune their plants a few nodes to create a firm basis for their plants and to limit the height considerably. That can make sense if, for example, you have a low ceiling in your grow space, but still want to have a large thick trunk and root system before you start flowering. Sometimes it is also applied to mainlining, a variation on the Screen of Green method. Learn more about this plant training technique in our guide on how to ScroG.
However, when you do this, you must bear in mind that the more you remove, the greater the attack on your plant's health and recovery time. If you want to use such a stressful procedure, your plants must be large enough for that. Wait until your plant has at least six nodes to ensure that the root system is well-developed.
The plant hormone auxin is responsible for vertical growth in plants, growing towards the light, developing this more classic Christmas tree shape. When topping cannabis plants, the entire growing top (also known by its scientific term "apical meristem") is removed, which means that the plant temporarily ceases to produce auxin. The lack of auxin growth hormones causes the plant to grow without direction, as a result of which plants often become a lot fuller and not much higher
When is the best time to top?
The best time to top or to bind/train your plants in radical ways is during the vegetative stage. The reason for this is that the plant has to recover from these processes: if too much stress is caused for a plant during flowering, it can be at the expense of the harvest and can even cause a plant to become hermaphrodite, which is something all cannabis growers would try to avoid.
The best time to top your plant and how often you want to do this depends on how large and how full you want your plants to be. If you assume that it will take seven to ten days for new shoots to start and grow, it is advisable to take approximately two weeks of recovery time for each time you top a cannabis plant. It is also very important to properly guide your plant during this process since the rest of the plant continues to grow, and there is a lot of new growth in the areas where topping has taken place.
Double your weed bud production
When growing weed, your success often depends on the number of buds you have, so the tops of your weed plant can have a huge effect on your culture. This not only increases the yield but also ensures that instead of one large central cola with many branches, different "head tops" without branches arise.
Below is an example of how often you can top a plant to get a certain number of head tops in your plant. When following this guide, you must, of course, bear in mind that the plant needs time to recover and that it is important to steer the growth that does continue.
The first topping forms two new stems
The second topping forms four new stems
The third topping forms eight new stems
The fourth topping forms sixteen new stems
Longer growth phase after topping cannabis plants
When growing a plant that has been topped several times, it is recommended to keep the plant in the vegetative stage for longer. The plant's hormonal system is disrupted for a while every time you top, making it a good idea to have the plates repaired as much as possible before the flowering phase is started.
The more of the plant you cut away, the longer it will need to recover. Certain chemicals can help the plant recover its strength faster and vastly reduce the chances of turning into a hermaphrodite plant. These can be purchased in your local garden center or nursery.
Topping with Low Stress training
If you follow this guideline for topping your weed plants, you have to take into account that your vegetative stage will take more time than untopped marijuana plants. While you let your topped cannabis plants recover, you can help the plant's vegetative growth to be more evenly distributed.
Very large plants are often kept in the growing phase for up to 70 days before they switch to the flowering stage; during this growing period many new stems are created that can be tied up. To control this plant growth, you can apply low stress training (LST in short). Read more about this growing technique in our guide to low stress training.
Topping with a ScrOG
Growing cannabis in a "Screen of Green" setup is an important reason for many growers to grow and can provide a huge yield of one plant. If a grower keeps topping over and over again, this may cause the number of leaves to be too heavy for the plant itself, which may make it necessary to support the plant.
When using a screen or a net, it is easy to tie all new stems with the same spaces between them. The use of ScrOG in combination with topping cannabis ensures that the lighting is used optimally and that you can get a huge yield from one plant.
Topping goes hand in hand with ScroG techniques. Having an understanding of both methods can, therefore, enormously improve your yields. Follow our advice, and you can look forward to wide, bushy plants with a fine crop.
What have we learned?
Topping cannabis plants has two main purposes: to increase yields, and to make sure the plant grows more compact. This technique is truly helpful for indoor growers who cultivate their cannabis plants in an indoor grow space, that tends to limit the room you have for your lovely plants. However you can also apply this method in your outdoor garden.
You know also know when you should top your cannabis plants, what strains fit best for this type of growing technique, and how to apply said technique. You can also combine topping with other plant training methods, like ScrOG, LST and mainlining. Autoflower growers can also check out our Topping Autflowers guide.
If you want to learn more about other plant training techniques, you can consult our grow guide for advanced growers. You can also visit our Learning Center for more guides and articles like this, can't hurt if you want to get a growth tip or two.