Unfortunately, plant size isn’t a very accurate indicator of final yield. In fact, it’s really hard to estimate the size of your yield just by looking at a single aspect of your plant (like height, for example). Cannabis buds develop on what growers refer to as “bud sites”. These are the spots on branches where pre-flower structures form roughly 4–6 weeks into a plant's life cycle. Once a plant enters its flowering phase, it stops dedicating its energy to developing foliage, instead focusing on producing healthy buds on these sites.
How big and dense these buds become depends on a lot of different variables, including light, nutrients, genetics, substrate, and more. The size of a plant, on the other hand, says little about how many bud sites it will develop, or how big/dense its buds will be come harvest. Light is arguably one of the most important factors affecting your yield. To maximise output, you should maximise light exposure to your plant early on by using training techniques to manipulate growth. One popular training technique is low stress training (LST), which involves bending and tying down branches to optimise light exposure and encourage a more horizontal structure. The screen of green (ScrOG) method takes this further, situating a mesh screen over plants, upon which new growth is woven in an effort to boost final yield. There are many more techniques where these came from, including high-stress tek like topping (in which the main growing tip is cut off) and defoliation, to name just a couple. Nutrients are also really important, and you’ll want to make sure your plants always have access to the macronutrients and micronutrients they need at each stage of growth. When it comes to nutes, your plants require different ratios depending on their phase. During veg, plants require higher levels of nitrogen, whereas flowering plants require more potassium, phosphorus, and micronutrients like calcium and magnesium.
In addition to the nutrients themselves, plants need to be able to uptake these nutrients to develop huge hauls of big buds. In order to do so, the pH level has to be dialled in for the type of grow you’re conducting. Arguably the most crucial factor that determines final yield are genetics. And just like there are some strains that taste better than others, there are also those that produce better harvests than others. Remember that cannabis strains have been bred to meet the demands of growers and consumers. And with yield being so important, there are countless strains out there that have been purposefully bred to produce numerous bud sites and develop bigger, heavier flowers. Make sure to check out some of our XL strains if you’re looking to really rake in the buds. There are many different grow media out there, and they all have different effects on the overall yield of your plants. While soil is easily the most common medium used to grow cannabis, hydroponic media like perlite or coco coir give growers a lot more control over the nutrient intake of their plants. And while that kind of control may be overwhelming for rookie growers, experienced growers can use it to really push their plants to the next level and produce massive yields. Whether you grow indoors or outdoors will have a big impact on your plants. Indoor growers generally have less space to work with, which means they’ll usually grow fewer, smaller plants than someone growing outdoors. However, indoor growers also have much more control over their plants’ environment. Hence, they can play around with things like lighting, temperature, and humidity to fine-tune their growing conditions and optimise yield. Outdoor growers, on the other hand, usually have much more space to work with than indoor growers, meaning they’ll be able to grow more plants in a single season than indoor growers. Plus, outdoor growers also have the benefit of growing under the best possible light source in the world—the sun. However, outdoor growers don’t have the same level of control over their environment, meaning their yield is subject to the season, which, depending on where you live, may be unpredictable. This is another important factor that affects your overall yield. The more fine-tuned your skills, the more control you have over your plants. And the more control you have over your plants, the better your yield. While yields vary a lot, there are some ways you can get at least a rough estimate of how much weed you’ll produce. Remember that cannabis plants will only grow as large as their pots allow them to. And while size is, as we saw earlier, far from the perfect indicator of how much you’ll harvest, it can help you get a ballpark estimate of what your harvests will look like. Ideally, you’ll want to grow in at least 18-litre pots. With this amount of soil, some decent nutrients, and some light pruning/training, you should be able to grow large, healthy plants that reach at least 90cm in height. Given they get a full 4–5 weeks of vegetative growth and solid lighting that penetrates right through to the lowest bud sites, plants of this size should be able to produce at least 100g of dry bud per plant.
Some growers choose to estimate their yield based on the strength of their lamps. And while this is far from an exact science, it can be a bit more accurate than calculating your yield per plant, especially if you choose to grow multiple smaller plants, rather than just a few larger ones. If you're growing indoors and have at least a few harvests under your belt, you can expect to harvest roughly one gram for every watt of light. If you’re a newbie grower with little-to-no experience, expect yields of around 0.5g per watt. Growing hydroponically gives you a lot more control over how your plants feed. With the right equipment and experience, this can greatly improve the size and quality of your yield. Experienced hydro growers, for example, can encourage yields of up to 1.2g per watt of lighting. By this logic—and using a 600W lamp—a good hydro grower can harvest over 700 grams of bud (genetics depending)! Remember, the weight of your buds will drop dramatically after drying and curing. So don’t get too excited when you weigh your buds right after trimming.
Instead, multiply your wet yield by 0.25 to get a rough estimate of how much dry bud you’ll end up with. HOW TO IMPROVE YOUR CANNABIS YIELD: QUICK TIPS FOR GROWERS.