Award-winning Kyle Kushman calls High Stress Training (HST) the chiropractic training technique. Others call it Super Cropping. Whatever terminology you may have heard, this technique harnesses physical stress to stimulate increased cannabinoid production and higher flower output. It's all about careful pruning, pinching, cracking, and bending.
Compared with the Low-Stress Training (LST), the HST option is a more advanced method — and one with increased risks. Applying too much stress through pruning and pinching, or applying it at the wrong moment, will do more harm than good.
If executed well, it refocused the plant's energy into cola production, cannabinoid development, and boost yields. Which is why so many experienced cultivators experiment with this technique.
Does the high-stress training technique feel daunting for you? It doesn't need to. The fundamentals are simple. With a little research from reputable sources, you'll have the tools you need to start experimenting within your indoor grow room.
The Benefits of HST (aka Super Cropping)
- Increased production of THC, CBD, and other cannabinoids
- Increased canopy space
- A shorter, wider plant
- Increased yields
- Stronger, more robust plants
The Basics of High-Stress Training (HST)
High-Stress Training manipulates the branches of cannabis in order to bend them into a more desirable shape. While there are several different techniques for bending (essentially damaging) branches, the aim is to promote stress.
When cannabis plants undergo a period of stress, they begin producing more cannabinoids. In nature, cannabis produces cannabinoids like THC and CBD as a protective measure against pests, disease, and the environment. When you purposely damage your plant, it will assume it's facing an environmental danger, thereby producing more cannabinoids.
Super cropping usually also aims to reshape the plant's canopy. Often high-stress training is an indoor growing technique that keeps plants short, and the canopy spread out. A more expansive canopy encourages bud development along branches (instead of just a single large cola at the end of the branch).
In this regard, high-stress training has the same end goal as low-stress training: bigger canopy development for indoor growing. However, the low-stress training technique specifically aims to reduce the stress of manipulation instead of purposefully increasing it.
How to HST Cannabis for Better Yields
- Proper HST is all about timing. Kushman recommends beginning the process in the last few days of the vegetative cycle. Do the damage, then allow the plant to heal while still in veg. Other growers have recommended pinching just before watering or adding a new round of nutrients, as this is when it is the most malleable.
- Prune first, removing all less productive branches, inner leaves, and shoots developing in nodes. Once complete, allow the plant to recover for several days, still under a vegetative light schedule.
- After several days, begin super cropping. Choose younger stems that are slightly bendy and malleable. Older branches turn quite woody, which will ultimately break under force.
- Technique 1 (Conventional Super Cropping): Pinch the stem between your fingers, try to squish the inner core. You may need to gently bend back and forth several times before you hear a crack. Careful bend to a 90-degree angle. Strive to break the interior (hurd) and not the outer surface.
- Technique 2 (Kushman's Chiropractic Approach): Hold the branch with both hands about an inch apart. Carefully crack the stem to break the interior but not damage the exterior. You will hear an audible crack. Continue to crack the stem every inch until the tip.
- Secure all super-cropped branches into the desired new shape. At this point, you may incorporate into a SCROG, securing the branches down into a trellis netting.
- Use tape or soft garden twist ties to secure. String or wire will eventually cut into the plant. Securing the plant into the new shape is important, or else it may simply heal back into its natural form. (You will notice knuckles or calluses form at the cracked sites as the plants heal. This is normal.)
- Using gardeners tape (or some growers even use duct tape), clean up any damaged bends where the branch's exterior has cracked open.
- Allow the plant to heal for several days under vegetative light before switching to flower.
What Products Do You Need for High-Stress Training?
Part of the beauty of the super cropping technique is that it doesn't require any special tools.
For the initial pruning, invest in a pair of sharp garden pruning scissors. For the pinching and bending stage, all you need is your hands. Finally, when it comes time to secure the bent branches in place, look for pipe cleaners, soft garden twists ties, or other gentle material.
Bigger Better Yields with HST
The ultimate goal of super cropping is to improve yields and boost cannabinoid content. The forceful manipulation causes stress, and eventually promotes a desirable vigorous response.
Yes, the prospect of purposefully damaging plants seems intimidating, but the results speak for themselves. Plus, growing cannabis is always about experimenting to improve the final flower. Before you switch into the flower cycle, why not experiment on a single plant with the super cropping technique?