Growing Cannabis Vegative Stage
Giving your cannabis plants a period of vegative growth means giving them access to continuous light for 18 hours or more.
During this vegative stage your plant is given the chance to grow in size without producing any buds. It is also a chance for them to gain some vigour and strength from their seedling or cutting stages.
You do not need to give a cannabis plant any vegative growth as long as the seedlings or cuttings have rooted correctly. If rooted, you can turn them onto a 12/12 light cycle immediately if you wanted. This is often done when trying to keep the plants shorter. Or if you are growing to time scales and rolling crops over at regular periods of say every 8 weeks or so.
So why veg a Cannabis plant
There are more than a few answers to this question, but I’m going to give you the main and most trusted reasons for vegging Cannabis.
The main reason for vegging marijuana is unsurprisingly, to increase yield one way or another. Whether it’s vegging for a scrog or just simply vegging a single plant to gigantic proportions, it always boils down to trying to increase yields. I have yet to meet a grower that veg’s for any other reason.
Vegging a cannabis plant just straight, meaning without any form of growth manipulation like topping, can give gargantuan yields; but is rarely ever practical.
If you have unlimited grow room height and width, adequate lighting and growing apparatus for the plants then give it a go.
But if you are one of the many of us that is restricted in regard to growing area and are only growing for personal use, then there are still a few awesome ways that you can increase yield by vegging.
How much light is right for vegging cannabis?
When vegging your cannabis seeds you will need to supply them with a minimum of 25,000 lux [per m2] and a maximum of 35,000 lux for optimum growth.
The term lux simply means the amount of lumens available per m2 when the lights lumens are directed towards the floor.
Contrary to popular belief, you can give too much light to cannabis plants when growing indoors. If you think about it for a minute it’s seems logical. Outside when a cannabis plant is growing, the light changes in intensity over the course of the day. The sun does not shine as bright at 10am as it does at 2pm.
In any grow room set up, the name of the game is trying to give the plant the correct amount of lumens for optimal growth.
If you go and bang a 1000w HPS up in a 1 m2 grow tent, it’s just going to be too intense for 18-24 hour period for 4-6 weeks.
Doing this will cause the plants to whiten due to a bleaching of their chlorophyll, and cause leaf cupping; basically you’re preventing optimum growth by using too much light.
You can use this chart to decide on what type of light you need and how many lumens are delivered by just measuring the floor space in your grow room.
Light intensity Chart for Cannabis
|Light Intensity (lux) Per Area Illuminated (m2)|
|Light Source||lumens||1.0 m2||1.5 m2||2.0 m2||2.5 m2||3.0 m2||3.5 m2||4.0 m2|
Distance to hang your light from plant tops
This is a rough guide to the distance that your lights should be hung at. You can sometimes decrease the distance and increase light intensity by either keeping an oscillating fan blowing over the tops of the plants if you have a good extraction system in your room or by using an air cooled light.
As a general rule, you’ll want to get your lights as close to the tops of your plants without burning them.
Also take into account the rate at which the plants grow. It’s no good having the lights hanging within a day’s growth if you can only check your grow room every other day.
These distances are as close as the lights should ever be to your plant tops. So if in doubt add 20% to the height; it’s far better to lower them gradually than burning your plants and having to raise the reflectors because they were too low in the first place.
LED Lights: 1 inch
Fluorescents: 3 inches
CFL: Three inches
High intensity Lights HPS or MH lowest hanging distances
1000W: 26 inches
600W: 18 inches
400W: 12 inches
250W: 6 inches
Type of light for vegging cannabis, HPS or Halide
I’ll keep this simple as there is no need to over complicate something that, well, just needs a brief explanation.
If you don’t mind spending the extra on having a metal halide lamp/bulb as well as a high pressure sodium [HPS] lamp for flowering, go for it and knock your pipe out.
But for all-round lamps that really do give the best of both worlds then go for HPS. The HPS lamps that are available today are so good at delivering the entire spectrum needed for fantastic plants and yields that you needn’t bother with anything else. Just read the grow shop reviews if in doubt or even give them a buzz, [on the phone] if you really feel the need.
How long should you veg for?
On average the amount of time the hobby grower veg’s for is 4 weeks. Sometimes when using a scrog you’ll go to 6 weeks to totally fill the scrog area; even 8 weeks on occasion; but that’s rare.
4 weeks of veg growth in most hydroponic systems is plenty. Soil is the exception and can take up to 12 weeks of vegging.
Roots and nutrients
What is often misunderstood when vegging your plants is that it is the greatest chance you will get at improving your plants root mass. This one factor alone can have your yields going up, up and beyond what you have ever achieved before.
More roots means the more food available to the plant, and the more food she eats the fatter she gets [as long as you have the right lighting].
Ways to increase root mass
Without going into huge detail here [because it requires a single post to cover in full], increase the amount of oxygen that the roots are receiving by adding another air stone or pump or increase the height of the drop back to the reservoir if using a recirculating system. Use rhizotonic, this will boost the root growth like crazy. Use superthirve always and forever. Get some of this, Plant Revolution Great White.
OK, so you should now have a good foundation as to why and how to veg your cannabis plants. Remember that less is often more when vegging. Too much light, too much nutrient and just too much of anything when growing cannabis will normally result in LESS of what you want… bigger and better quality yields.
Vegative growth and other factors
All components that you need for growing cannabis successfully combine to give you the final result.
Your overall yield, quality and taste all depend on how close to optimum your lighting, nutrients, ph level, oxygenated water, nutrient solution temperature, humidity, temperature [in your grow room] and co2 are.
If you have all of these elements of growing cannabis absolutely nailed down to the perfect levels, then you should find your seeds delivering what they say on the pack. But there are still no guarantees.
It’s unlikely that you are going to get the quoted 800g m2 of white widow by planting a few seeds in soil and shoving them under some fluorescents’.
But maybe someone out there can… I have never seen it though.