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Everything You Need to Know About Light Depping

Light depping at its simplest is mimicking light conditions to force your plants to flower. It is also known as light deprivation or “depping.” Most commonly, light depping is used to mimic Fall light conditions, which will force cannabis plants to flower earlier in the season.

Understanding Light Deprivation

When it comes to light depping, all you are really doing is tricking the plant into thinking it is the Fall season. Once the plant thinks that Winter is coming, it begins to produce a large amount of flower. It does this to prepare to produce seeds that would drop to the top soil and keep the plant alive for next year. However, you won’t end up with seeds at the end of your light dep run. Instead, you will end up with sweet and delicious cannabis to use as you wish.

To trick the plant, you simply need a light protective tarp to put over your greenhouse. This will allow you to manipulate the hours your plants see light and do not, which is exactly what we’re aiming for.

Why light dep in the first place?

There are number of reasons people choose to light dep. For starters, it means you could potentially get a few extra harvests in each year. With the ability to start early, you can be pulling down a light dep harvest right before Summer planting should begin.

Additionally, when you grow within a more controlled environment, you are able to more easily control pests. Therefore, your ability to grow stronger and healthier plants increases. And, who doesn’t love strong and healthy cannabis plants? We know we sure do!

Lastly, the reason we light dep, to avoid male pollinators in the air. Unfortunately, where we are located, we have a lot of hemp farms surrounding us. Since many of the hemp farms nearby are not sexing their crops, there would have been male pollinators in the air. Because of this, if we had planted for the normal outdoor growing season, we would have likely ended up with plants chock full of seeds. And, no one would have been a happy camper.

Instead, we opted to plant early, pull the tarp and still reap the benefits of the harvest via light depping.

Setting Up A Light Dep Environment

In order to mimic the light conditions, you will need a few supplies first. These include the following:

  • A greenhouse or hoop house
  • Light proof plastic
  • Proper ventilation setup

There are a number of ways you can choose to set this up as well. Whether you want to build raised beds, use 30 gallon or larger pots or plant directly into your soil, the choice is yours.

Our Light Dep Setup

Personally, we built two raised beds that fit three plants each in them. Once the beds were built, filled, amended and baked for a few weeks, we went back out and built a hoop house out of cattle fencing over the two raised beds. By bending the cattle fencing and bolting it to some two-by-fours, we were able to create a simple, yet effective hoop house. With a walkway in the middle, so we could easily access all of the plants.

Plus, since the cattle fencing has large openings, we could easily inspect the harder to reach spots from the outside. After that, we simply purchased a large tarp to throw over the hoop house, which was weighed down on the ends, so no light seeped in.

Ready, set, let’s grow!

Now that you’re all set up and ready to go, there are just a few more things you should be aware of on your journey to successfully light depping.

Make a Schedule

First, you will want to make a schedule and stick to it. Think about it, the sun doesn’t get to sleep in, does it? Nope, so neither do you! If you decide that pulling the tarp at 5 AM is what’s needed, be prepared to wake up that early for the next two months.

To decide on the times you should have the greenhouse covered, you’ll want to look at:

  • the sun’s position in relation to your plot,
  • when the plants will be shaded,
  • and your schedule.

This will help you determine when the best times to keep your plants uncovered and covered is.

For example, if your plants are fully exposed to the harsh evening sun and humidity, you may want to look at covering them earlier in the evening, then pulling the tarp back off once the sun sets to let them breathe for the evening (see below about ventilation).

In the end, it all really depends on your region’s temperatures, humidity and light conditions.


However, beware! If you choose to put your tarp on late in the evening, you need to remember that it has the opportunity to build up loads of moisture throughout the evening. As the Earth begins to cool for the evening, all of that moisture will be trapped within your greenhouse. And, that’s leaving you susceptible to mold – gross!

To prevent this, you have a few options. Typically, in greenhouses, you will see an exhaust fan on one side and intake shutters on the other. This allows for nice air flow throughout the greenhouse.

However, if you made a hoop house from material lying around the yard like we did, it’s a little more difficult. For us, we simply chose to wake up super early and throw the tarp over prior to the sun rising. Then a few short hours later, we would pull the tarp right back off. This way, the plants were only covered each day for a few hours. Thus, not allowing moisture or mold to form on the plants.

Of course, if you aren’t a morning person or are looking for a simpler way to do this, they do sell electronic arms. These arms pull the tarp on and off and can even be put on a timer system. Don’t worry, we’ll be investing in one soon enough!


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Avoid Light Leaks

With the electronic arm, you can almost always guarantee that your tarp won’t get ripped or shredded along the paneling of your hoop house. However, most of us aren’t fortunate enough to own of those, so here we are manually pulling and putting the tarp on every day; sometimes more than once a day.

Of course, this means you may end up with light leaks, which you don’t want. If you purchase an extra durable tarp, you should be free and clear of light leaks, but if you went on the cheaper end, you may be dealing with a little bit of a mess.

During your growing season, you may want to dive into that pitch black hoop house to ensure there are no leaks. The simplest and best time to do this is right before you pull the tarp off in the morning.

Since the plants are already expecting to see the sun in a few minutes, they won’t mind a little sun from you hopping in their house. Now that you’re in, simply look around and see if you can see any light coming in. If you can, grab the duct tape and some spare tarp, then get to patching those holes up.

It’s important to do checks like this every week or so. If you choose not to, you may be disappointed come harvest time, as your plants won’t have had the chance to fully develop.

Remember, it’s essential that your plants get twelve hours of consecutive darkness to flower properly.

Start from Clones

Okay, so you’re all set up and have the best tips to create the perfect environment for your cannabis plant friends, but do you really want to start from seed? Heck no!

Do you know what that involves? Determining males from females, waiting for them to get large enough to even flower out in the first place, possible plant weaknesses and so much more!

So, we strongly recommend you start from clones for your light dep harvest. By doing so, you can be sure that your plants are the “cream of the crop” prior to planting outdoors.

Whether you purchase the clones or made them yourself, you will need to do a few things prior to planting them outdoors. Most likely, your clones came from indoor grows. And, if this is the case, you need to know that they aren’t used to the full power of the sun or wind.

Due to this, you will want to harden them off. To do this, simply bring the plants outside for a few hours each day, so they are able to get used to the sun and weather conditions in your area. You will want to increase the length of time outside over the course of a few weeks.

Once you believe the clones are strong enough to endure the outdoors full time, get ready to start transplanting them!

Caring for Your Light Dep Garden

Now that everything is planted and ready to start growing, there’s not much else to do. Of course, you will want to be sure to water regularly, as well as check your plants for any deficiencies.

Once the plants begin to stretch, you may find it necessary to add a trellis, net or tomato cage around the plants for support. We ended up having to use two nets at varying heights over the course of the growing season to ensure the plant remained upright.

Additionally, you will notice that many bottom branches are attempting to produce buds, but they are small and not quality flower. If this begins to occur, you can choose to trim back some lower branches. This will allow for the plant to focus more of its efforts on the large top buds instead.

Another option, if you don’t want to chop away at your plant, is to let it keep on growing naturally. If you choose to do this, when it comes harvest time, do not chop your plant off at the base. Instead, chop away the large top branches and leave the bottom branches intact.

Then, go have fun trimming all that bud and leave the rest to continue flowering for another week or two. By doing this, the bottom branches will now have a chance to form larger buds. This allows you to harvest the rest of the plant once it reaches the end of its grow cycle. Thus, getting a little extra out of your harvest.

Alright, you’re ready to start light depping! Now, go grow some stuff and let us know how it goes!