Increasing the yield is always the key goal at the end of the day in any type of crop production. I always try and explain this in terms of space when gardening under lights, as opposed to talking about how many plants you can fit in the garden. Basically, understanding how to efficiently produce the optimum amount of fresh weight per square foot of surface area under each light will allow you to achieve the maximum possible yield and production.
For example, when you grow a plant outdoors there isn’t really any space restriction because the plant has virtually unlimited root space and equal light penetration from the sun throughout the day. This allows a plant to grow full and thick, without the sparse wispy straggler growth resulting from lack of light or restricted root development that you might see in an indoor plant receiving only overhead light from reflectors.
Under normal circumstances, this wispy growth is always underdeveloped come harvest time and should be removed prior to initiating the flowering cycle—if not, the result is wasted time and plant energy that would have been better utilized in the primary tops, fruit or blooms on the plant. Indoors, using artificial lighting, a single lamp can cover only so much available surface area effectively—opposed to the sun, which covers the entire circumference of an outdoor plant.
My personal translation of this logic is that outside plants can most definitely reach their maximum possible yield without pruning, trellising or training if they are given a sunny location and adequate water and nutrients and protected from things like pests and mold. Indoors, though, each grow lamp can only cover ‘X’ amount of surface area, most commonly on a horizontal platform; it’s up to us as growers to determine the most efficient way to produce a full canopy under this available surface area and turn wispy growth into primary growth.
Trellising techniques and super-cropping
Trellising techniques and super-cropping can really benefit the grower in terms of maximizing production surface area with fewer plants. Trellising utilizes a nylon or plastic monofilament grid sectioned out in specific increments of length and width. These nets—comprised of multiple squares—will allow you to train a plant from having what were once only a few tops (primary shoots) into dozens of tops, each one occupying an individual square in the trellis net.
Common trellising techniques might include wooden or PVC custom frames that serve to hold and spread the trellis flat or parallel with the canopy. Trellis systems are usually applied to mature vegetative crops prior to the flowering cycle, so that each plant has enough time to train itself into the grids of the trellis.
You should build your trellis supports in ways that will allow you to maximize the footprint of your available light. Traditionally, the common understanding is that a 1,000 watt light will support approximately a 16 square foot footprint; with a trellis this might be increased up to double the size, as long as there is enough plant mass to sufficiently fill in the surface area of the trellis.
This technique will also encourage shorter finishing heights, as the plants will grow out horizontally instead of vertically. Currently, this is definitely the most popular way of maximizing yield without increasing the number of plants in the garden. This kind of trellising—sometimes called SCROG or ‘screen of green’—might be conducted with many plants or few.
Personally, I feel that fewer are generally better; otherwise, what is the point of the trellis? A downside to this technique is that longer vegetative growth periods are required in order to grow a larger plant capable of filling in a big trellis grid, but at least you’ll only have one plant to tend, as opposed to the many single plants you would need to produce the same yield. Outdoors—and in indoor grows that utilize vertical lighting—trellises can also be spread vertically to function as sturdy supports for tall, longer-season varieties.
Super-cropping is not a new technique, but it has continued to be a popular solution as the gardening industry has evolved. Super-cropping involves taking primary branches of a plant and creasing or bending them in such a way that it not only shortens the plant, but promotes a denser canopy over a larger surface area.
Rather than having several tall primary tops on a plant, these are creased over to the side between the nodes of the plant and either tied down, trellised or left to heal as is. Over time, the crease will form a thick, callused, elbow-like knot and permanently fix the branch in place without the need of bamboo or twist-ties.
This super-cropping technique works well on most types of soft-stem plants that have a tendency to grow tall—you can employ it in any situation where trellis grids are not available and plant training is required. Tomatoes, basil and pepper plants are all great candidates for the use of super-cropping strategies to increase yields.
In order to increase yields and benefit from trellising and super-cropping, plant health must be also be carefully maintained. Bugs always seem to be a big problem for most gardeners across the board, no matter what their level of expertise might be.
This is a part of gardening that I always recommend approaching with extreme caution, though, as many products use harmful ingredients and plants usually don’t respond in a positive manner to them. For example, Abamectin is a systemic insecticide that many commercial or large-scale growers have used in their rooms in an attempt to control infestations of spider mites, thrips or whiteflies.
This scheduled group six insecticide is extremely toxic to humans, animals and the environment and should be reserved for use only on ornamental and non-consumable crops. The extreme danger associated with this product is enough for me to never recommend it for use to anyone!
Imidacloprid is another pesticide ingredient that is beginning to gain some popularity among those who run into root-dwelling insect infestations. Root aphids, thrips and fungus gnats stand absolutely no chance against this systemic toxin and even though it is registered for use on vegetable crops I would still caution against it. Many countries have banned this product due to the huge numbers of native insects it has killed off.
Although not ‘kill-on-contact’ effective, ladybugs are an excellent preventative measure that will work full time in your garden so you won’t have to. Ladybugs are predatory in nature and their favorite foods are plant-dwelling insects—including spider mites, aphids, whiteflies, fungus gnats and thrips.
Ladybugs are most effective once their breeding colonies start to flourish—the larvae will feast on smaller pests like mites while adults prefer fat juicy aphids. By no means are ladybugs the cure to a major pest problem in the garden, however—if you are struck by a serious infestation you’ll need to employ a spray that will kill bugs on contact in order to effectively reduce their population.
The reason for this is that plant-sucking pests breed much faster than most beneficial insects, so trying to curb large infestations with ladybugs will usually prove ineffective. They’re more of a maintenance measure—you can put ladybugs in vegetative rooms and clones to ensure clean, pest-free starts and they will even burrow down into the growing medium in order to retrieve tasty root aphids and fungus gnats.
Try using these tactics to improve your crop production. For me, gardening is all about trial and error—in order to become better, you must first fail. Trellising and super-cropping are grower-devised techniques used to improve crop yields by manipulation of plant growth patterns.
Some failures are inevitable in order to achieve success using these techniques—don’t freak out if you break a branch off your first time trying to super-crop your plant. As with anything, practice makes perfect, so throw up a grid and get started—soon you’ll begin to see maximized yields in your own garden.