Do you know how to stop plants from growing tall? Are you aware of the reasons you should?
Big, bushy weed is a bearer of good news, but skinny specimens aren’t. Besides reducing future yields, thin crops tumble sideways, burn against lights, and waste pricey nutrients. Call that a nuisance!
What can you do about the sudden lankiness?
Join us to learn about the causes of overstretching and discover how to keep your weed plants short.
Here are the reasons why your cannabis plant is growing too tall and skinny
Why is my plant growing tall and skinny? This problem is frequent among growers, especially in indoor spaces. The answer is the first step toward a proactive course of action.
Here are the common culprits for unrestrained and unhealthy height.
Long vegetative stage
Each part of a crop’s life cycle plays a role in the final product. The four flowering cannabis growing stages are when the magic happens, but vegging is equally essential. This phase supplies the healthy greenery that later becomes home to bud sites.
Why is my weed plant growing tall and skinny? Vegging might hold the key.
Marijuana has evolved to continue stretching for as long as there are 18 hours of light and 6 hours of darkness. When you put it in an indoor setup where days never shorten, it continues growing and waiting for a change in the photoperiod.
Vegging can last between 3 and 16 weeks, but up to 12 is optimal. Your cannabis plants are too tall soon after.
Distant and weak light source
Cannabis grow lights replicate the sunlight in indoor grow rooms—their effectiveness hinges on positioning and intensity. Insufficient and poorly placed lamps can make marijuana plants too tall by triggering unwelcome evolutionary responses.
Marijuana strives to tower over the competing plant life and absorb more sunlight. Distant lamps trip the same response, forcing it to elongate and compensate.
Weak lamps cause a similar issue. Your vigorous vegging crops don’t know whether the source is distant, scarce, or shaded—excessive expansion is their go-to response to light issues.
Not enough light from the sides and too much from the top
Learning how to make weed plants bushy often entails installing off-center lamps. Overheads are insufficient in isolation, and an extreme lack of side light leads to leggy phenotypes.
When lights come only from the top, marijuana seeks to maximize the available source. It extends past its limits in the desire to feed new growth.
This issue is common with older lamp models, which produce narrow beams. It also happens when plants sit closely together, preventing side penetration.
It’s all about genetics
Sometimes, cannabis plants are too tall by design.
Some strains, especially landrace sativa varieties, are predisposed to a stretchy and spindly stature. You can’t do much except manually reduce their height.
Consider alternative ways to tackle bendy branches and light issues. Opt for a short and bushy indica if space is an issue.
Plants are too close to each other
Shade avoidance response is a change that occurs in plants when neighboring vegetation sits too close. Affected phenotypes grow tall to reduce the amount of shade they receive.
This issue is frequent in cultivars with strong side branches. If you place them far apart at the start, they soon get wide and encroach on one another’s spaces.
As a rule of thumb, you want at least six inches between the branches of each crop. Half a foot is ideal if you’re wondering how to grow short, bushy weed plants.
Why is being too tall and skinny a bad thing for your plant?
Why would you learn how to keep plants small? Because it brings numerous benefits and cuts much trouble from your cultivation journey.
Skinny weed is more vulnerable to health conditions that might hamper your harvest. Excessive height also causes problems with logistics. Frequent troubles include:
- Weak stalks—as the stem elongates, it loses girth and sturdiness. The result is a slim and bendy structure that could break under the weight of buds and foliage.
- Nutrient deficiencies—elongation redirects nutrients from where they’re most needed. Our guide to cannabis deficiencies investigates issues that might crop up.
- Light burn—when plants sit too close to lamps, they exhibit dry, bleached colas with scarce cannabinoids and terpenes.
- Flowering stretch—early flowering induces a growth spur that could double crop size. If your garden is already tall in vegging, blooming brings about space issues.
Why bother with these issues when you can read on and discover how to make plants grow out, not up?
How to encourage horizontal growth and stop a plant from growing too tall
It doesn’t matter whether your weed plants are too tall because of a gardening error or the strain’s natural tendency. Bushy crops are always desirable, and here’s how to get them.
Choose dwarf cannabis strains
Are you thinking about how to keep plants small? Genetics is key. Some strains are tall and slim, but others have evolved to produce squat, Christmas-tree structures.
You’re generally safe with indica—it rarely reaches four feet in height. If you want to take things further, pick the following cultivars lauded for their ‘dwarf’ stature:
- Royal Dwarf feminized—rarely advances to 2 ft tall
- Critical Kush feminized—3 ft tall in all environments
- Easy Bud feminized—approximately 2 ft in height
Vertical netting condenses crops, maximizes space, and improves light penetration. It’s a top choice if you’re considering how to keep marijuana plants short.
The idea is simple: get a framed net in a lattice pattern and position it over your garden. Branches with new buds bend and shoot through the gaps. As a bonus, the frame stops crops from touching the lights and burning.
You can buy a trellis or DIY one at home. Place the mesh screen above and around plants after pruning large leaves. Tighten it in place and inspect daily, moving any stuck branch by hand.
Enlarge your grow space
Cannabis gets taller when other plants invade its branch space. Making your grow room more spacious is conducive to bushy growth.
Plants are happy with around half a foot between them and anything that could cast shadows. Most growers can make this happen by shifting pots away from each other. You might sacrifice walkability, but the results are worth the trouble.
Prune and trim your cannabis plants
Topping and pruning matter for any garden, but they double in importance if your cannabis is too tall. In these cases, removing excess plant material can make or break the grow op.
Weekly defoliation reduces the shade, nipping the height issue in the bud. Topping limits crop size and increases yield potential.
Besides regular foliage maintenance, an intense pre-flower trim may salvage a lost cause situation.
If your vegging plant is already super-tall, reduce it to half its desired final height. Cut the stem, branches, and most of the foliage, and flip to flowering after a week.
Marijuana can recover from being diminished to a stalk. You won’t see much residue while bud trimming, and harvests won’t suffer.
LST and bending
Low-stress training is an excellent way to control the growth traits of weed crops. This approach involves bending branches without breaking them to achieve the desired shape.
Are you wondering how to make plants grow out, not up? Bending is the solution.
Tie the stem parallel to the edge of your space, keeping it low to the ground. This way, the side becomes the canopy, and hidden branches now get light exposure. You receive an even bud spread and fatter, juicier flowers.
Tip: Start low-stress training in early vegging. Stop as soon as your garden starts blooming, as stress can affect output.
Shorten the vegetative stage
Cannabis plants are too tall due to long vegging. Shortening this life stage counters excess stretching.
Marijuana must reach a certain size to carry buds, and most specimens need only several weeks to achieve that structure. Everything past 60 days is unnecessary.
How do you shorten vegging?
It’s easy indoors. Flip the lights to a 12/12 schedule, providing equal light and dark hours each day. Be mindful of light leaks.
Outdoor growers have two options:
- Covering crops with opaque materials
- Carrying the pots into a light-proof room
Protect your plant from heat stress and light burn
Distant lamps make cannabis too tall, but having them too close is also a health concern. You need to find a happy medium for healthy development.
Lights can cause two health issues: heat stress and light burn.
Heat stress protection revolves around climate control. Ensure excellent air circulation, humidity levels, and temperature ranges.
Even if your lamps are cool, overexposure can dry and bleach your flowers. Get a lux meter and measure the amount of light surrounding the foliage. Optimal ranges are:
- 35.000–70.000 lux in vegging
- 55.000–85.000 lux in flowering
Employ reflective materials
The light must reach the sides and the top of the crop for a healthy canopy. Reflective materials are a budget-friendly way to ensure well-rounded exposure.
These materials reflect light instead of consuming it. They improve side exposure and lamp penetration. They’re the go-to answer on how to make weed plants bushy.
Effective options to consider include:
- Plastic foil
- Latex paint
The first two are common for tents and a cheap one-time trick for rooms. Reflective paint is a long-term and cost-effective solution if you have a dedicated cultivation space.
Height control for prosperous cultivation
Between our advice and weed’s inherent sturdiness, you shouldn’t fret when your cannabis gets too tall. Solutions are simple, and no hope for a big harvest is yet lost.
Remember these takeaways for getting your grow op back on track:
- Stretching results from evolution, but you can prevent and alter these tendencies.
- Stick to good gardening practices to keep crops hardy. Optimize your lamp use to help them develop rich foliage.
- Don’t be afraid to employ training techniques for height control.
Now that you know how to stop plants from growing tall, why not put your skills into practice? Visit our selection of cannabis seeds, and cultivate marijuana at home. Stay tuned to our blog for guides on all things ganja.