Hey all,
The following questions/answers are based on my own ScrOG experiences and research…not definitive by any means…
First off, there are many variables to consider. You really need to know the characteristics of your particular strain to plan for a ScrOG, so it’s probably not a good idea for your first grow. That being said…
1. What strain is best for ScrOG? You can grow most strains using ScrOG, you just have to vary some things based on strain (more later).
2. Hydro or soil? Both can be used successfully. You need to consider 3 below, though (for example, if I’m growing in soil, how am I going to flush the soil if the plant is tangled in a screen?)
3. Will I be able to move my plants once under the screen? Depends. If you fix the frame of the screen to your growing container then you will be able to move the container, plant, and screen as one. If you fix the screen to something else (like a wall) you won’t.
4. How big should I make the screen? Depends on your light. You want about 50-70 watts per square foot. So if you have a 250 watt HPS, you can have about 4-5 square feet…say a 2’ X 2’ screen area.
5. What kind of screen should I use? You can use netting, chickenwire, DIY using string, etc. The important thing is to have at LEAST 2” squares to make it easier to feed the branches/leaves through. I made my own netting with 3” squares.
6. How high should I place the screen? Depends on your strain. You’re looking to get some branching going before you reach the screen. With pure Indicas you tend to get bushy plants with tight nodes and you can set the screen at 8” from the base (12” if you want some room to work under the screen). Pure Sativas are less bushy and airier and you would probably set the screen at 18” – 24”. Set the screen between 12” – 18” for Indica/Sativa strains, depending on how bushy/tall it grows.
7. Can I grow from seed? You can…so long as you’re able to sex the plants before you put them in the screen. It’s best to grow from known females. It's easiest to grow from clones that you're familiar with.
8. How many plants should I grow? Depends. For example, you could fill up a 3’ X 3’ screen with one Indica plant; but it would take several toppings and a long veg period to do it. Two plants would take fewer toppings and less veg time, and so on. Generally, you don’t want to exceed one plant per square foot, might as well do a SOG then.
9. How high should the light be? It should be as close as you can get it without burning the plant, same as any grow.
10. Should I do any kind of training (topping, LST, etc.) before the plant reaches the screen? Again, depends on the characteristics of the plant and how much screen it needs to fill. Is it a bushy, stunted Indica? Or a stringy, tall Sativa? Is the plant going to fill a 1’ X 1’ or 2’ X 2’ area? And so on.
11. How much of the screen should be filled up before I initiate flowering? This is a key point and it depends on the strain and how much it stretches once you start flowering. You will continue to train the plant under the screen for 1 – 3 weeks after initiating flowering, until the stretch phase is over and flowering begins. You really need to know your plant, but the following are general guidelines: for a bushy Indica that has little stretching, you can start 12/12 when about 80% of the screen is filled. For a Sativa that stretches a lot you may only want 50% of your screen filled. For Indica/Sativas maybe 60-70%.
12. Should I trim fan leaves so that bud sites get light? Touchy subject…I personally will tuck or tie back a leaf first; if it’s still in the way I’ll cut it in half; but if that don’t work I won’t hesitate to snip it off it it’s still in the way of a bud site – bud sites take priority over fan leaves for me.
13. How should I deal with the under screen growth? It’s best to cut away any fan leaves and underdeveloped branches from underneath the screen to allow for better ventilation.
14. How do I deal with ventilation? The leaves and branches are going to be packed in tight and humid, an invitation for molds and bugs. I run two oscillating fans, one underneath blowing up at the leaves and one directed over the canopy.
15. How do you keep the canopy growth even? The whole purpose of a ScrOG is to get an even canopy of buds. If some branches grow taller faster than I’ll supercrop (pinch) them to slow them down. If others are lagging, then I’ll tuck, tie, or trim the fan leaves around them so they get more light, and so on.
That’s about all I can think of off the top of my head. Use at your own risk.