Growing your own weed is a joyful experience. But it will keep you on your toes, as your desire to improve will require you to stay alert. If you’ve already been through a flowering cycle or two, you have already grown leaps and bounds in your knowledge and understanding of the plant.

We remember what it was like to be blissfully ignorant about everything. I chuckle when I look back at the early days of the legal scene in Oklahoma and how we were just so eager to get started. But knowledge is power, and knowing what to expect will help you better manage your plants and avoid problems.

When it comes to growing weed, there is always something going on with the plant. It is maturing and growing every day. How it is now is not how it will be in the future. Having a grasp on what the plant is wanting to do will make all the difference in how tedious or smooth your runs will be.

As we explained in the last article, marijuana plants can and do “stretch” during their life cycle. This article will discuss when that occurs and how long it usually lasts.

What is the “stretch” period for marijuana plants?

The term “stretch” can actually refer to a couple different concepts in cannabis cultivation. One concept is that of the plant growing in a way that it literally appears to be reaching in a certain direction. This can be seen during the vegetative phase when growing indoors.

Marijuana Plants stretch during the vegetative stage if the lights are too distant

During the indoor vegetative phase, the immature plant is looking to gain height. In order to grow, the plant needs the photosynthesis that comes from the lights. For whatever reason, we have regularly observed that when the lights are higher or away from the plants, the plant will grow toward that light, in what looks like an apparent attempt to close the distance.

If the light is too high, the plant will appear to stretch toward that light. We use the term stretch because the manner in which it grows appears to be just that: a plant stretching in terms of length only, with no other growth. The result is an immature plant that looks tall and skinny. But more concerning is the stress this “stretching” can put on the plant.

Any form of stress is wasted energy that is not used to power the plant in a more productive manner. We want to avoid unnecessary stress. Thus, we want to avoid inducing the plant to stretch during veg.

Marijuana Plants will stretch during the first three weeks of the flowering period

There is another form of stretching that occurs during the flowering period. This type of stretching is known as the Post-Vegetative Stretch.

When a plant transitions from veg to flower, the environmental changes trigger a tidal wave of new growth. This new growth causes the plant to soar in height as well as explode in foliage. The reason for this growth is the increased recovery period of having an equal amount of darkness (recover) to light (growth) from the 12/12 light cycle.

For new growers, the post-veg stretch can be a source of continuing problems for the remainder of the flowering period. The key is managing the stretch is to understand the timing of it, and how to not only respond, but act preemptively.

How long is the post-vegetative stretch for marijuana plants?

You will begin seeing signs of the post-vegetative stretch in your plants beginning toward the end of week 1 and definitely throughout the second week of flowering.

This stretching will continue through week 3 and will usually not appear to slow down until about the fourth week of flowering. That is when things will start settling down.

And what exactly do we mean by this phrase, “post-vegetative stretch?” As in, how much will the plants stretch? Well, glad you asked, because now I can tell you what to expect. Your plant will literally double, maybe even triple, in size!

Imagine checking on your plants and every other day you are noticing new growth. Leave for three days and come back and wow! Your plants will be stretching for the ceiling, and bushing out in all directions.

How to prepare for the post-vegetative stretch

There are several things to consider. One is your ceiling height. Are you growing in a tent or in an open room? Regardless, you will want to have sufficient space for your plant to grow and stretch during this time. The most important consideration is having distance between your plants and the lights.

You do not want your plant growing into the lights. This can cause light bleaching, as well as heat stress. Therefore, ensure there is plenty of distance between the lights for your plant to double in height and stretch away.

Another consideration is managing your plant with tools such as bamboo sticks or trellis netting. We prefer trellis netting, and believe trellis to be absolutely vital to successful cultivation indoors.

Lastly, the best way to manage the post-vegetative stretch is to prepare for it during the vegetative stage. In a separate article, we cover several things that can be done during the vegetative period to prepare for the stretching that occurs in flower.

What if my marijuana plant does not stretch after switching to 12/12 light cycle?

If your plant does not stretch after switching to 12/12 light cycle, then something is wrong. Here are a few troubleshooting tips.

First, check your light timers. With all the technology these days, things can still go wrong. Sometimes it seems like these software applications and gadgets have a life of their own.

We once experienced an episode where our plants did not seem like they were growing very much after two full weeks under 12/12 lighting. I mean, we saw growth. But not the explosive growth we had come to expect.

It wasn’t until about the third week that discovered an issue with our light timer. Something had triggered it to revert back to the 18/6 light cycle. We don’t know how often it was reverting back or exactly what was going on. But what we did know was that our plants were not stretching as much as we had come to expect. And that observation led us to discover a problem with the timer.

We were able to solve the problem, get the plants back on track. We just ended up with even larger plants since they had an extra few weeks of vegging before flipping.

Marijuana Plants will not stretch if the roots are restricted from growing

Another possible cause of your plant not stretching could be the size of the growing container. As we saw in our Red Solo Cup series, a plant can only grow if its roots are allowed to grow. Restrict the ability of the roots to grow with a small container, and the overall grow of the plant will be restricted as well.

Other than those two issues, an otherwise healthy plant will stretch away during the first few weeks of the flowering period.

To recap, prepare your plant ahead of time with proper pruning and topping in veg; use trellis netting immediately upon switching your light cycle to flowering; and make sure you have the space to allow for the plant to stretch.


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