Training Your Plants: Pruning, Staking and Trellising to Maximize Yields

Environment has a lot to do with the way plants behave. This innate flexibility in some plants makes it possible to modify their growing habits to make them more compatible for specific indoor environments like grow tents, growrooms and greenhouses.

A number of gardening strategies can be used to manipulate plants in different ways to maximize resources like space, nutrients and light. Often, these measures also produce stronger, healthier plants and result in increased yields.

Although trellising, pruning and staking can be considered separate and sometimes unrelated tasks, within the confines of a growroom or other indoor set-up, they often work together as part of a larger plan.

In an outdoor garden, plants have room to sprawl, and light is more diffused, providing indirect coverage to lower plant leaves.

An occasional light breeze can supply adequate airflow. In an indoor garden, however, these important elements are supplied artificially within a confined space. This creates challenges that can be minimized through careful pruning and training techniques.

Atypical dominance is an excellent example. It’s the inclination of plants to grow from their top-most leaves, branches and stems—locations where the light is most abundant.

In the growroom, uneven distribution of foliage caused by atypical dominance can result in stunted growth for all but a few light-monopolizing, top-heavy plants. This can also occur in nature, but its effects are devastating in a growroom setting, where even small imbalances can cause big problems.

Beyond enhancing individual plants, either by controlling atypical dominance or in other ways, judicious plant training can improve the way an entire growroom performs. Understanding these principles and coming up with ways to exploit them can make indoor gardening more successful and satisfying.

What Does Plant Pruning Do?

Pruning involves trimming leaves, stems and even flowers or fruits from a plant. In a growroom, selective pruning can accomplish many things:

• Directing growth
• Stabilizing plants
• Making harvesting easier
• Maximizing space
• Improving airflow
• Enhancing light penetration
• Protecting plants from diseases
• Helping produce larger flowers and fruits

Some pruning methods vary depending on the plant variety and objectives involved, while others are standard. Removing dead or dying leaves is a common chore that reduces the risk of plants contracting diseases, for instance. Eliminating low-lying foliage is another familiar pruning task that helps plants develop more efficiently, and may have the added bonus of providing enough extra space for the intercropping of lettuces and other small plants.

Another advantage of selective pruning is that it will encourage plants to behave in ways that help them flourish in the artificial environment of a growroom. For example, even though most tomato varieties are bushy, selective pruning to remove axillary buds and encourage central stem growth can transform regular tomatoes into vining plants that are easier to maintain indoors because they use space efficiently. Similar results can also be accomplished with sweet peppers.

This is an exciting approach to indoor gardening because it allows gardeners to modify plants for the better by using simple, natural, inexpensive techniques. Pruning may be considered a labor-intensive practice, especially when training plants to grow differently from the way they’d develop naturally, but it can help grow healthier, more robust specimens indoors.

Plant Supports

As a general rule, plants taller than 24 in. need some type of support. This is particularly true in a hydroponic set-up, where roots are grown without soil and in an environment where they aren’t encouraged to spread out. Stakes or support collars are often adequate for plants under 4-ft. high, but once plants grow taller than that, they need additional bracing. Options for larger plants include teepees, frames and grow cages.

There are a number of plant support products on the market, as well as DIY variations that make use of simple materials like bamboo and chicken wire. Outdoor supports like tomato cages can be modified for growroom use, and net trellising can be useful, too.

Netting is a relatively inexpensive choice that can accommodate many different crops and growing strategies. It might not provide the sturdy structure some plants require, though, and may need additional reinforcement over time. There are also grow screens that work in tandem with tie-down and other special plant-training techniques.

When figuring out plant supports, the overall layout of the growroom should be taken into consideration. Most experts recommend planning for adequate supports early, sometimes even during set-up, or at least before plants are large enough to need reinforcements, to make the most efficient use of space.

Plant Trellising

Another popular choice is growing plants vertically using string or wire suspended from a frame installed below the growroom’s overhead lighting system. This technique is an effective use of space that can also help make pruning and other maintenance easier.

Vertical training is popular for vining plants like beans and peas, or plants that can be trained to imitate the growth habit of vines, like tomatoes and some peppers.

A string trellis suspended from a strong framework will support a vining tomato that can weigh up to 40 lb. and grow up to 18 ft. or more under ideal conditions.

The basic idea is pretty simple. One end of a length of string or wire is affixed to an overhead bar or beam, and the other end is secured in a relatively straight line to the base of the plant or growing container.

As the vine grows, it’s fastened to the string at multiple locations and supported using ties or clips. The vine is trained along the vertical string until it reaches the top.

This allows for closer plant spacing and better access to plants for care and harvesting. It also promotes good airflow and may increase light penetration over other cultivation methods. Multiple vines can be trellised in manageable rows using this method, provided the support frame is sturdy enough to hold them.

Setting up a string trellis can be as simple as using basic materials like PVC, metal conduit, twine, pipe cleaners and eye hooks. When you’re securing heavy plants, or lots of them, some special equipment will make the arrangement more functional.

Plant clips designed especially for string trellising have small channels that grip the string securely, and large diameters that provide support without the risk of girdling or cutting plant stems. These accessories are inexpensive and reusable. Once in place, they don’t slip and can be repositioned easily without damaging plants.

Adjustable trellis hangers or roller hooks, sometimes called yo-yos, are another handy tool. When dealing with long vines, using an adjustable hanger makes it easier to create slack in the line. This lowers the plant, making it lean or sag.

It’s a creative way around ceiling or light elevation limitations, where the available vertical space won’t accommodate mature specimens. The idea is to grow plants as high as possible, and then drop and lean them somewhat to exploit any unused lateral space.

In a growroom environment, influences are often magnified and the way one plant develops will have an impact on others nearby. Effective cutting and training strategies do more than produce better individual plants. They help create a more efficient, productive and dynamic growroom.