Vegetative Stage

During the veg stage your plants will direct all their energy to growing larger.  The healthier the plant is during growth phase, the better the results will be during flowering.   The plants are building up energy and weight to be used during flowering so I actually spend much more time with my growing plants than my flowering ones.  Just don’t let them get too tall before you switch them to flower because they can double in height during flowering.

Things You’ll Need:


Ok, so you have a few options for lighting during the growth phase.  I prefer LED lights, but they can be pricey compared to other options.  If controlling air temperature with ventilation will be difficult in your veg room due to a lack of windows or exhaust vents from your growing area, you should probably use flourescent or the best option would be LED lighting  These lights produce the most light with the smallest amount of heat.  High intensity Metal Halide lights would probably grow your plants the fastest, but also use the most energy and produce the most heat, so you’ll have to ventilate air in and out of the room to keep everything cool and healthy if you already have or plan to use HID lighting in veg.


LED lights can be confusing to purchase, many list wattage numbers that are not even close to what the unit actually uses.  This is because LED lights are so much more efficient than lights that use gas or filaments like flourescent and HID lights.  A 500 watt LED is equivalent to 1000 watts of high intensity light from a bulb.  A small LED like the smallest one listed above says it’s 300 watts, but it’s actually about 150, and is perfect for covering a 3 foot by 3 foot plant canopy.   If your growing area is larger than that, perhaps you should consider getting a larger unit, the model labeled as 1200 watts will cover a 6 by 6 area well.   The main benefit to using LED lights is high efficiency and low temperatures.

Flourescent Lights:

T5 bulbs are the most common form of flourescent bulb in horticulture growing, and most commonly used for growth but not flowering.  They produce a good amount of light with minimal heat, but the light intensity is weak and penetration into the canopy is low.  With these bulbs the benefit is their low price and low heat output.  A 4 foot 8 bulb unit is perfect for a 4 foot by 4 foot canopy, but will consume over 400 watts of energy, so you can see it is much less efficient than LED’s.

Metal Halide:

1000 Watt Double Ended Metal Halide bulbs are the industry standard for commercial grows here in Colorado, and they can cover up up to a 6 by 6 foot area.

There are other lights that will work in veg, like induction and plasma, but they are rare and expensive so I won’t even get into it here, but if you already have one they will work fine to grow with also.

If you are going to use MH lights, you probably will need a way to cool the room.  If the light brings the rooms temperature above 80 degrees Farenheit the plants won’t grow as well, anything above 95 degrees and the plants will probably die.  If you have air conditioning, you can always use that, but it is far less efficeint than just moving cooler air from outside into the room and pulling hot air out of the room.  Unless you live in a tropical climate, a set of fans and ducting should be sufficient to cool any room without AC.  Swamp coolers can be used in desert climates, but the high humidity they create can present issues for your plant’s long term health.

2. – Cooling