weed timer

Cannabis Light Schedules: Vegetative Stage vs Flowering Stage

Cannabis plants keep getting bigger and bigger with long days, and start making buds when you give them long nights.

Cannabis is a “photoperiod” plant, which means the amount of light received each day decides when the plant starts flowering or making buds. This article explains how much light a day your photoperiod cannabis plants need to grow and start budding, so you get to a happy harvest day. What about auto-flowering strains?

Vegetative – Seedling or clone leads to Vegetative Stage –
Give 18-24 hours of light a day

Flowering – Flowering (Budding) Stage leads to Harvest –
Give 12 hours light & 12 hours dark each day

Seedling or Clone

While not technically a “stage,” all grows start with cannabis seeds or clones.


Plant your seeds or clones when you’re ready to start growing! What are clones?


Some outdoor growers start their plants indoors to give them a headstart before putting plants outside.

If you’re growing cannabis outdoors with seeds, you should wait until a few weeks after the spring equinox to put your seeds outside. In the northern hemisphere this means seeds go outside in-or-after April, In the southern hemisphere seeds go outside in-or-after October.

For growers starting with cannabis clones, generally you should wait a few weeks longer than with seeds. Cannabis clones are more prone to flowering early outdoors than seeds, so you might want to put your clones out in late Spring or early Summer. (What are clones?)

If you live in a cold climate, you must also wait until after the last frost before putting your plants outside. Freezing temps will kill cannabis plants. Strain choice is very important. Some strains flower earlier than others. For outdoor growers in cold climates, it’s important to make sure you grow a strain that is matched up with your local weather, so that plants are ready for harvest before temperatures drop.

Vegetative Stage

The vegetative stage is one of the most important parts of the life of your cannabis plant.

The vegetative stage is the growing stage of the plant. When in veg, cannabis plants grow bigger and taller, growing only stems and leaves. As a grower, you are able to control the size and shape of your plants in the vegetative stage using simple training methods.

During the entire vegetative stage the plant does not produce buds at all. It only grows stems and leaves. During the vegetative stage plants tend to grow very fast, especially when conditions are right.

What keeps cannabis in the vegetative stage?

Short nights keep cannabis plants in the vegetative stage. You can keep a cannabis plant in the vegetative stage for basically forever as long as the plant continues to get short nights (shorter than 1s-12 hours, depending on the strain).

Cannabis will stay in the vegetative stage as long as the plant gets short nights (less than 11-12 hours of darkness each day)

Whether you’re growing indoors or outdoors, you must make sure your cannabis plants get at least 13 hours of light each day to stay in the vegetative stage. If your plant gets a few long nights, it may start budding before you want.

The plant can receive as much as 24 hours of light a day while in the vegetative stage. Many indoor growers provide 18-24 hours of light a day (known as 18-6 or 24-0 light schedules) during the vegetative stage to encourage faster vegetative growth.

Don’t want to worry about light schedules? For growers that don’t want to pay attention to light schedules, there are auto-flowering strains of cannabis, which will automatically go through their whole life in about 3 months no matter what light schedule is provided. For some growers, an auto-flowering strain may be more simple than a traditional (photoperiod) strain.


Most indoor growers provide 18-24 hours of light a day (known as 18-6 or 24-0 light schedules). Giving your cannabis plants more hours of light each day in the flowering stage will encourage faster growth.

Lingo: When a grower provides 18 hours of light a day and 6 hours of darkness, this is commonly known as the 18/6 light schedule. For 24 hours a day, this is referred to as the 24-0 light schedule.


As long as your plant is getting plenty of light a day, your plant will automatically stay in the vegetative stage from late spring until late summer. Every strain is a bit different.

Flowering Stage

Cannabis starts budding when plants get at least 12 hours of uninterrupted darkness each night. After plants start budding, they must continue to get long dark nights until harvest or they may revert back to the vegetative stage.


Indoors most growers put their plants on a 12-12 schedule to initiate flowering. Outdoors the plant will naturally start budding in late summer when nights are growing longer and longer as winter approaches. Just make sure plants aren’t exposed to light during their dark period!

What is 12-12 Lighting?

The indoor grower will need to artificially induce flowering/budding in plants by changing the light schedule so the plant receives only 12 hours of light a day, and 12 hours of uninterrupted darkness.

Once the plant is changed over to the flowering (12/12) light schedule, there is generally another 6 weeks-5 months (average 2.5 months) before the plant’s buds are ready for harvest.


Outdoor growers wait until their cannabis plants start naturally flowering on their own, usually after mid-summer when days start getting shorter than 12 hours.

It’s important to make sure plants aren’t exposed to light at night during their dark period, even street lights or spotlights, as this can prevent cannabis plants from flowering properly.

Growing Indoors? Not Sure When To Switch To Flowering?

So indoor growers have a choice to flower their plants whenever they want… When is the best t ime to start flowering your cannabis indoors?

The real answer is that it’s a matter of personal preference and also depends on what end result you’re looking for. There are two major considerations when choosing the right time to switch to 12/12, the age of the plant and the height of the plant:

Age: Some growers feel that a marijuana plant which has been grown from seed will not produce as many buds or have enough resin production if the plant is not given at least 60 days in the vegetative stage to mature before it’s changed over to the flowering stage. This is not true. many growers initiate flowering soon after germinating a seed in order to keep plants small and short. This is often called “12-12 from seed.” Just remember, no matter what you do, a young cannabis plant will not start flowering until it is 2-3 weeks old. Even if you put a seed on a 12-12 schedule from the beginning, it will not start properly budding for about 3 weeks. When growing with cannabis clones, age is not an issue and growers can switch directly to flowering once your clone has established roots. This is because even though a clone may be small, it’s still a ‘mature’ plant since it is made of a piece from a mature plant. Rooted clones tend to grow much faster for the first few weeks than plants grown from seed. In any case, age is not much of an issue, and you should switch your light schedule at the time that best fits your needs.

Height: A general rule is that your marijuana plant will double or triple in size during the flowering stage from the point where you first change over the light schedule to 12/12. Some plants will grow more, some will grow less, but a good rule of thumb is to change your light schedule over to flowering when your plants have reached half of their final desired height. Bending, known as “LST” or “low stress training” can be used to control colas that get too tall. Simply bend too-tall colas down and away from the center of the plant. Some growers will even slightly break or “supercrop” branches to get them to bend at a 90 degree angle. For those growing in a small space, height may be the primary concern. However, there are many techniques available to grow a short, bushy weed plant or basically train your cannabis plant to grow into any shape you want.

Here’s an example of LST to keep a plant short:

In optimal conditions if height and space is not an issue, you would probably want to vegetate your cannabis plant for 60 days or more before switching it over to flowering. This gives your plant plenty of time to grow big (so you get bigger yields), and allows new growers to dial in their grow before plants enter the sensitive flowering stage. In the vegetative stage, it is easy to recover from problems, but problems are a lot more serious in the flowering stage, where mistakes can dramatically hurt your final yields.

Giving cannabis plants more time in the vegetative stage, and taking time to train them to fit your space, will give you the best final yields. However, if space is tight, then it’s better to switch when the plant is half the final desired height, or even to just attempt to flower your cannabis plant straight from seed.


After the vegetative and flowering stage are over, it is time to harvest your plants!

What do I need to know about light cycles and flowering my marijuana plants? Plants keep getting bigger and bigger with long days, and start making buds when you give them long nights.

Best Digital Timer for Growing Weed Reviews 2020

Oct 7 · 5 min read

Growing weed at home is an idea that has captivated many people, especially marijuana enthusiasts. Nonetheless, it is fair to say that only a small percentage of newbie cultivators actually end up being successful. Even if you follow things by the book, success is not absolute. More than the right knowledge, you also need to have the right tools, such as the best digital timer for growing weed.

Using the best digital timer for growing weed is important because it ensures the proper monitoring of the grow room. This makes it easier to control the environment, making sure that it is in accordance with the needs of the plant. Clueless on which timer will make the best option? Keep on reading and we will list down some of the top products that are guaranteed to provide the best bang for the buck.

Why You Need a Timer for Your Grow Lights?
If you want to garden indoors, making sure your plants get the right amount of light is essential. Otherwise, your plants will fail to reach their full potential, so you won’t get the same yields you would achieve with proper lighting.

By getting a timer for grow lights, you can automate the process of providing your garden the right amount of light. No more having to remember to switch them on and off yourself. Instead, the process is automatic.

To put it plainly, timers for grow lights simplify your life. When you use one of these handy devices, you don’t have to worry about whether your plants are getting enough light at the right times. The timer does all of the hard work for you. And, if you are going to be away from home for a few days, they are even more important for keeping your indoor garden in great shape.

How to choose a grow light timer?
You should always use the timer that is going to present the most accurate amount of hours that it has been in use for. You should also check about the longevity of the timer. You will also need to know how long will you be able to use the machine before it starts to incur damage. In order to learn more and more about the product, do not hesitate to consult the reviewers that are online and ask them about their experiences with the products that they have already been using and which you are looking to buy.

From the online reviewers, you will be able to get a lot of information about the machine and how it works. You will also be able to ask them about the type of customer service that the manufacturer offers and how they deal with the issues raised by the customers. In all this, a person that already is using the machine will be able to guide you perfectly for what you will face when you purchase the same product.

In addition to all of the above, you should also look for a timer that is not going to get physically damaged very easily when you are moving it from one location to another. You can always check out the structure and the materials with which this grow light is built with and this can be something that will make all the difference when choosing two very good grow light timers form the market.

You should always go for the product of a brand that is not easily going to be broken under pressure. This will help you get a timer that will work for many years to come without having you run for repairs constantly to the manufacturers.

You should always look for the instructions on the manuals of the machine that you just bought. This will make sure that you know everything about the timer and by taking notes about the most important things, you will be able to use the timer for a longer period of time. This will also increase the shelf life of the product significantly.

If you have a large hydroponic system and if you are looking for a digital timer that can help make your life more convenient, this is one option that should be part of your list. This will help provide a consistent amount of light in your hydroponic system, which is essential for its productive growth.

Looking at the features of this plug-in timer, you can set the desired time in advance for up to seven days. You will be able to control two outlets at a time. You will also be able to set eight on and off cycles per day.

Another thing that makes this a good product is the small display that makes it easy to monitor the time and to set the desired preferences. Under the screen, the buttons are strategically positioned.

It should be noted, however, that this is rated for indoor use only. An outdoor digital timer should be protected from harsh weather elements, such as rain.

The BN-LINK Timer is one of the best selling timers on Amazon. It’s truly a set-and-forget timer with 2 total outlets. It has 8 settings you can use to ensure you get the exact amount of light and darkness you need for your plants. This timer has a 1725 watt capacity.

  • It has two outlets that you can easily set up to handle long hours of usage. You have the choice of whether or not to set the timer for a long hours or just a few minutes.
  • You can choose your own scheduled day setting or select the preset from the machine. You can easily switch from the normal hours to daylight savings without difficulty.
  • The timer’s digital so you do not have to worry about manual operations. All you have to do is to set the hours up, and it will work automatically.
  • You can even set it up to work while on vacation. This way, your house will not look empty at all.
  • It can work in any indoor location from the office to a fully-functioning greenhouse.

Final Thoughts
In addition to a good marijuana grow tent and hydroponic system, your LED grow lights are a crucial aspect of your grow operation. When choosing a timer, we recommend using one with a digital design and substantial safety features. Any of the timers on our list make excellent choices for an indoor grow room. It’s just up to what you are looking for and the budget you’ve set for yourself.

A timer is a lifesaver for any indoor grower who wants to save time and energy and protect their indoor plants for overexposure.

Growing weed at home is an idea that has captivated many people, especially marijuana enthusiasts. Nonetheless, it is fair to say that only a small percentage of newbie cultivators actually end up…