How container size and trellising can have a big impact on your harvest.
Many growers associate immense yields only with commercial or industrial-sized grow operations. While it’s true that larger spaces afford more opportunities for heavier yields, it’s also true that techniques deployed in large-scale grows can be incorporated into home gardens.
While the primary focus for those interested in larger yields is on growing larger plants, growers should not sacrifice quality for quantity. This means that growing larger plants isn’t the only objective; we also want happy and healthy plants. Plants that are stressed will not achieve their full potential in terms of both quality and yield. By using some simple and effective horticultural techniques – such as larger plant containers, a smart pruning program, and trellising – growers can achieve a heavy harvest with quality flowers.
To begin, young plants should be transplanted into large containers during their vegetative stage. Depending on the space available, growers will usually opt for containers that are no less than 20 gallons when growing for heavy yields (some indoor and greenhouse growers may even go for 50- or 100-gallon containers). It is important to remember that the size of the plant’s root structure ultimately dictates the size of the plant. Therefore, using larger plant containers is the first step in obtaining larger plants.
The type of container – not just the size – can play a key role in determining both yield and how happy your plants are.
The newer fabric pots offer some of the best features for plant containers: They are not only durable and easily drained, but they ensure maximum breathability for the root zone, allowing air – most importantly, oxygen – to permeate the grow medium and reach the roots for uptake. Keep in mind that roots take in oxygen (O2), while the rest of the plant breathes carbon dioxide (CO2).
Many people new to growing in the great outdoors imagine that they have unlimited “container” space, as they envision the earth as one giant pot to plant in. However, even outdoor gardens require specialized plant sites – and this doesn’t just mean containers, but also a properly prepared grow medium. Often, regular earth soil is not of a high enough quality to grow healthy pot plants, and most topsoil will require some amending.
In fact, many outdoor growers either use gigantic plant containers such as grow bags (in the volume of hundreds of gallons) or construct their own frames for growboxes. In both cases, the plant’s roots are free to extend down into the earth, but most of the time they remain in the containers, where they can find the rich medium (usually compost and peat-based soilless mixtures) and nutrients they need to thrive.
The next step in creating bigger, bushier plants is to employ a smart pruning program. Pruning cannabis plants is generally done in the earlier stages of development and not during the flowering stage. Pruning is essentially a tradeoff: The grower removes one branch in order to get two more. Depending on the technique, some pruning methods may garner four or even eight times as many branches for the price of sacrificing just one.
This occurs because when a plant suddenly loses a limb hormones called auxins signal a growth spurt in the pruned or damaged area. However, growers must take care not to overprune their plants, which can put them in a state of shock and burden their internal processes with too much stress, causing slower development.
Most growers who employ a pruning program prefer to take off the top, or terminal, shoot. The result is that two offshoots directly below the cut begin to grow vigorously and become two main top shoots, creating a pair of top colas instead of just one. If this technique is employed sparingly around the top and sides of the plant, it will create more main shoots and increase not only development, but also yields.
Trellising is perhaps one of the most underrated techniques in all of cannabis horticulture. It can be used in any setting in both indoor and outdoor gardens, and is one of the few practices that is wholly agricultural and not found in nature.
A trellis is a system of latticework or crosses, created with any material such as wood, steel or string, that helps to support a growing plant’s limbs; the trellis can also be used to train the plant to grow in certain ways. When used in conjunction with smart pruning techniques, a trellis system can help to increase yields by as much as 20 or 30 percent.
Trellising should be put into place over a garden while the plants are still very young and in their vegetative phase. Indoor growers often use string or rope netting, as it is extremely flexible and can easily be cut to fit over any size garden. When using string trellising in an indoor garden, it is usually advisable to secure the trellis system about six inches above the garden canopy to allow the plants to begin to grow up and through the trellis naturally. As the plants start to get pruned, new offshoots will grow vigorously and should be carefully trained outwards and up through the net.
In greenhouse and outdoor grow ops, where space is less of a concern and plants can grow much larger, various types of trellising can be created to suit a garden’s needs. In many large-scale grows, the trelliswork is typically deployed in a vertical fashion, as opposed to horizontally in smaller indoor gardens. This is mainly due to the fact that outdoor plants grow more like actual trees and can reach heights of 10 to 14 feet (or even taller). In these situations, many farmers utilize tall wooden or metal structures to help stabilize plants and spread their limbs to encourage outward growth.
In an outdoor setting, growers have a choice of many materials from which to create a trellis system. Perhaps one of the most ingenious employs basic metal-wire rebar used for concrete forms. Rolling this material into a cylinder (approximately three feet in diameter) and placing it around individual plants can work wonders: As the plants grow upwards and bush outwards as the result of smart pruning, the additional limbs are pulled through the squares of the trelliswork.
Aside from the support the branches get, there are other important benefits of trellising. As the limbs are spread apart, there is much better light penetration allowed throughout the entire plant. The spreading of limbs also allows for maximum airflow. The added respiration aids in photosynthesis and also helps prevent moisture buildup that can lead to mold or botrytis. But the primary function of the trellis is to support and stabilize the top and lateral shoots created via pruning. In the end, these extra limbs are what produce the added weight that will boost your yields come harvest time.