How Long to Veg From Seed

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Growing cannabis is about more than just planning on what you’re going to do with your buds. You’re going to need a certain level of expertise when it comes to the growth cycle of these plants, especially if you care about your eventual yields.

One of the most important stages is the vegetative phase, which will help to determine the fate of your plants.

What is the Vegetative Phase?

The vegetative phase is, for at least most first-time growers, the point where growing cannabis really starts to get exciting. This is the time when your plant goes from being a mere seedling to a fully-growing plant, growing leaves and increasing in size.

This is the third stage of growth for your plant, coming after it germinates and becomes a seedling, but before it starts flowing.

The Importance of the Vegetative Phase

The vegetative stage is very important because this is the stage in which your plant starts to get bigger. Since the yield that you can get from a plant tends to be directly related to the size of the plant, you have to be very careful with your plant in this stage.

Green cannabis leaf, indica vegetative growth stage

This isn’t to say that you can’t get a good yield from a smaller plant, but rather to point out that this phase is going to end up being vitally important for the crop that you eventually reap.

How to Achieve Ideal Vegetative Growth

Now that you know how important vegetative growth is going to be to your crop, you should take some simple steps to ensure that you get the ideal vegetative growth for your plants. Though this is obviously going to vary quite a bit based on a number of different variables that are in play, keeping all of the following factors in mind should help you to end up with a better yield at the end of your growing period.

Indoor vs Outdoor

It’s always good to start with the location of your plants. If you’re growing inside, you’re going to have a lot more control over your plants than if you were growing them outside.

This not only means that you’ll be able to keep track of the conditions inside your growing area, but that you’ll also be able to play around with the biology of your plants in a way that you simply couldn’t do outside.

With this said, the control means you’re going to do a lot of extra work. Not only can you control all of the variables indoors, but you have to do so. This means that you’re going to have to undertake some of the work usually done by nature, which means a lot more time with your plants.

Outdoor growing is essentially an opposite situation. You don’t get to control the lights or the weather, but you also don’t have to spend as much time ensuring that the atmosphere is perfect. You’ll spend more time rigging irrigation and dealing with pests, but you’ll never have to worry about how to set your lights or ensuring that the humidity in your grow space doesn’t get above a certain percentage point.

Starting with the Seedlings

Regardless of where you choose to grow, you’ll need to start by taking care of your seedlings. The health of your seedlings is going to play a huge role in how your plant grows, so you’ll need to baby your seedlings a bit.

This means that you’re going to need to pay attention to all of the factors discussed below.

Growth Medium

Cannabis can be grown both in the soil and hydroponically. It’s vital that you ensure that your growth medium always has plenty of space for your plants’ roots to grow, that it has the right kind of nutrient base, and that you ensure that the medium is rich enough to allow your plants to grow well later in life.

Simply put, the growth medium is the foundation on which you will end up building the future of your plants.


Next up come the lights. If you have never grown cannabis in the past, you probably don’t understand exactly how important light is for the growth of these plants. It’s nearly as important as water, and it’s going to end up playing a huge role in how well your plants flower.

If you are going to grow indoors, you’ll need to make sure that you have an excellent set of LED lights to help your plants grow out of the seed stage. These lights are also going to be invaluable for photoperiod strains of cannabis, as you’ll need to keep the vegetative plants fully lit for between eighteen and twenty-four hours a day.

The more light you can provide inside, the better – at least, if you’re using photoperiod strains. If you’re growing autoflowers, on the other hand, light will still play a role but you won’t have to be quite as active. As you might imagine, though, this isn’t exactly the kind of problem you’ll deal if you’re growing outside.


What you feed your plants matters. Make sure that you’re not just giving them water, but also the nutrients that they need to grow.

Cannabis marijuana purple rose background with plants of violet hemp in led fito pink light. Plants in vegetative period. Cannabis bushes botanical abstract background

This generally means nitrogen, potassium, and magnesium at different stages of the plant’s growth.


Water, as you might imagine, is vital for both the seedling and for the vegetative state. Your goal is to hit the sweet spot between over and under watering. This usually means water, then waiting for the first few centimeters of soil to dry out before you water again. If you’re growing in hydro, though, you won’t need to water at all.


You’ll always want to keep your plants at between 68 and 86 degrees Fahrenheit. Likewise, you’ll need a humidity level of around forty percent. If you can’t achieve these numbers regularly outside, you’ll need to grow indoors.


Your plants need to breathe in CO2 to grow. This means having fans to bring in CO2 and to move out oxygen as it is produced. Again, this is an indoor-only issue, so don’t worry about it if you are growing outside.


Yes, you can train your plants. In this case, it means shaping them to grow to certain heights and in certain shapes, which will maximize their flowering potential and allow for better sunlight and water absorption. This can be tricky for first-time growers, but it’s a skill you should learn.

The First Two Weeks

All of the factors listed above are important throughout your plant’s growth, but they’re vital during the first two weeks of the vegetative state. As such, you need to closely monitor your watering, temperature, humidity, and airflow during this time and to ensure that your plants are getting all the nutrition they need to flourish.

Other Factors to Keep in Mind

While all of the factors above are incredibly important, there are some other factors that you can keep in mind when your plants hit the vegetative states.

Close-up CBD cannabis plant and hemp inflorescence with water drops. Ganja Leaves Macro view. Vegetative stage of medical marijuana growth

You’ll want to make sure that you’re prepared to undertake a few basic activities in order to ensure that your plants reach their maximum potential during this phase.


If you’re looking to grow cannabis, you’ll need to get your male flowers out of the growing area ASAP. The time to do this is relatively early on, around a month after your seeds germinate. Look for the plants with the round ‘pre-flowers’ in order to find the males and then remove them before they can pollinate your female flowers.


This is also a good time to properly space your plants. Proper spacing allows your plants to get more light, to expend less energy trying to absorb resources, and it provides fewer places for parasites and fungi to live.

Your goal is to give your plants enough room to flourish without cutting down on your potential harvest by too much.


Finally, you’ll want to ensure that your plants don’t get too tall. While tall plants might look great, they’re not as good at providing room for buds to grow as broad plants. Doing this is as easy as cutting off the top part of the plant’s stem at the right time, which will allow your plants to grow wider and end up giving you a much better yield.

Understanding the Vegetative Phase

It’s very important that you understand all the phases of your plants’ growth. Doing so gives you a much better chance to not only get a better harvest, but to keep your plants productive for a longer period of time.

The vegetative state might not be the state in which you get the buds you need, but it’s going to determine the success or failure of your operation. As such, you’ll want to make sure that you treat your plants right during this time.