Troops, we have some work ahead. We will soon be flipping our light cycle to 12/12 for the bloom cycle. But it’s not all rainbows and unicorns, ya see. We have to get through the upcoming stretching that is on the horizon. Time to be like a Boyscott and get prepared!

What is the post-vegetative stretch?

When you switch your light cycle from Vegetative (18 on/6 off) to Flowering (12 on/12 off), your plants will go through a tremendous growth spurt. This growth spurt can cause a lot of foliage growth, even under growth. But most of all, your plants will growth in vertical height in such a manner that has always been described as “stretching.”

The change in light cycles causes the plant to essentially double (even triple) in size and height.

This increase in size is great, and should be welcomed as the next step toward harvesting some amazing bud. More is better, right?!

But for the unweary, this rapid increase in height can cause a number of problems and present various pitfalls for the new grower. We’ve been there ourselves, and have learned so much in this area of cultivation.

In fact, properly managing the post-vegetative stretching that occurs in the initial weeks of flowering has been one of the biggest game changers for us, both in terms of quality and quantity. It’s not too often that you can win at both of those aspects in cultivation. Read on to learn more about how to win at this stage.

How to prepare for the Post-Veg Stretch before switching to 12/12 light cycle

Here is a key that we eventually learned on our journey as cultivators. You must get prepared before switching to the flowering light cycle. And that means taking advantage of your opportunity to train your plants during the vegetative stage.

During the vegetative stage, there are several decisions that you can make that will either make the stretch period more challenging or easier to manage. We will discuss those below.

Avoid topping your plant too early in veg

Of all the tips we have learned, this one has made the biggest difference. And it is completely counterintuitive.

We all know the benefit of topping. It prevents us from having a tall and skinny cornhusk for a plant, right? Well, yes, that is true, as topping will create more tops, as well as allow side branches to catch up. However, if you top an early stage veg plant when it lacks any height at all, you create more problems in flower, especially during the stretch period.

When you top a small, early stage veg plant, you actually encourage more lower growth later on. Think about it. You have a single stalk, however young and pliable it may be. Now you cause it to fork by topping it. But what you’ve really done, is tell the plant to create several branches forking out of the very bottom of the plant.

Now, when you flip that plant into a flowering light cycle, everything grows, including those lower branches. So you just doubled the amount of defoliation and trimming work you have during flower.

But we have a better approach.

Wait until your vegetative plant is taller before topping it

If you wait until your plant is two feet tall or so, you will have a better outcome topping it. Because at this point, you have a decently tall plant. Before you top it, prune off everything near the bottom. Have nothing growing for the first 12 inches or so.

Now when you top the center, the upper branches will catch up to the center. You are encouraging vertical growth and growth of the upper branches.

To the contrary, when you top an early stage veg plant, you encourage lower growth. Since you literally instructed the plant to fork out right at the bottom, as you will always have foliage down there. This will only be exacerbated by the post-veg stretch that comes during the first three weeks of the flowering period.

Avoid overgrowth of the bottom branches during the stretch period

By delaying your topping schedule during the vegetative period, you reduce the amount of lowering growth that would’ve occurred during the flowering period. And this is the single best thing you can do to avoid a much more labor intensive stretch period.

We have experienced this first hand. Pruning and defoliating unnecessary lower branches eats up time and labor, and is completely avoidable.

All of the other tips we are going to share are still very valuable, but this first tip really influences the effectiveness of the other tips.

Prepare for the stretch by pruning your plants in vegetative stage

You know that after you switch your light cycle from 18/6 to 12/12 that your plants will go through an explosive growth spurt. They call it a “stretch” because your plants grow vertically in all directions. And with that, comes growth of the fan leaves and all the little branches poking out.

When the main branches stretch, so does all of the accompanying foliage. And this requires you to prune this foliage so maintain airflow, allow light penetration, and cultivate healthy buds. So why not get ahead of this?

You can in fact get ahead of this task by pruning your plants during veg. We recommend that you first prune your plants prior to topping them, as described above. You would do this by growing your plant to at least two feet in height, and removing everything for the first half, i.e. about the first ten to twelve inches.

A week later, you would then top the center of your plant, and let her grow some more. Then, the same week that you intend to flip into flower, you should prune her up again.

Trim all or most of the fan leaves off, especially in the middle of the plant. But really pay attention to the lower half of the plant. Go ahead and remove all those little branches that have made a second attempt at growing.

Now, you’ve thoroughly prepared your plant for the stretching that is about to occur during the first few weeks of flowering.

Use Trellis Netting during the Flowering Stage to Control the Stretch

The last and final aspect of managing the stretch period is to use trellis netting to control your plant.

Before switching your light cycle, spread the trellis netting over the plant. Then, as the plant begins to stretch, weave the branches outward, and through the netting. This will increase yield by allowing more and more growth to occur in the center of the plant. Further, by drawing the plant out and you allow those branches to bloom more and more flowering sites as well.

The biggest concern about the post veg stretch is that uncontrolled growth can result in the plants growing into the lights, burning and bleaching themselves. Another concern, is unmanageable defoliation, especially when growing in commercial facilities. The work load can grow out of control if left unchecked.


Use your time during veg to prepare for the best success during the flowering period, and you will indeed achieve it.


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