Sativas in raised bed - advice needed

[ipchains]

Hello fellow ACErs,

Hope all of you are well and have good start of new season

After 3 years of struggle I finally realized 20-25l amended living soil is definitely not enough for 150-180cm mainlined sativa plants (they constantly got rootbound at 8-12 weeks of flowering). Planning to switch from autopots to aquavalve feeded custom raised beds (please, read automatic bottom feed hempy raised bed here) - 300L of living soil for each group of 4 plants. As usual, already read hundreds of thematic posts but still got some questions asking for answers

1) Is there a real need to topdress if I put enough nutrients in starting soil mix assuming I have 75L of soil per indoor plant?
2) Had someone already tried to experiment mixing standard and slow release dry organic fertilizers and amendements in flower beds for long flowering sativas? Plan to use Biotabs + Dr. Earth + Jobes Organic's Organic Fert Sticks for container plants along with base soil mix. Trying to be smartass here to avoid topdressing during flowering I feed from bottom, topdressing works a bit differently with Autopots and Aquavalve, at least for me...
3) Some tips for height control without ability to make plant root-bound?
4) Any other essential tip or point for growing in raised beds I'm totally missing?

Cheers!

P.S. I'm pretty sure Benoit or any of you guys rocking with Autopots would be of great help here

 

[chilliwilli]

After a year of using my soilmix i noticed some drop in vigor like less stretch after switch. I think i will use half of what i have added to the mix as topdress and then look how the next grows turn out.
From my experience i can say less is more when it comes to fertilizers.

 

[therevverend]

There's no need to top dress. You can feed to need by mixing the same nutrients into water. That way you have more control over how much and how quickly they get the stuff. Otherwise it's more of a guessing game. I like top dressing in the ground in native soil when I want the stuff to slowly leach in but in flowering in soil mixes you need more control. Unless your mix is weak.

 

[ipchains]

Thank you, chilliwilli! I'll definitely consider to go on the lighter side of the mix, sounds very logical assuming each plant will have 3x more soil.

 

[ipchains]

There's no need to top dress. You can feed to need by mixing the same nutrients into water. That way you have more control over how much and how quickly they get the stuff. Otherwise it's more of a guessing game. I like top dressing in the ground in native soil when I want the stuff to slowly leach in but in flowering in soil mixes you need more control. Unless your mix is weak.

Thank you, absolutely makes sense.
Thing is I always thought dry nutrients needed to be prepared as a tea (with air pumps and etc) to be effective or could it be just mixed in water? I just do not have a luxury of brewing teas for 24-36 hours (busy as hell on a work ).

 

[therevverend]

Just mixing it in water with a stick is fine. Let it sit overnight or mix it in the morning and wait a few hours if you have the time. It might still be chunky but that's okay. It's still broken down and more readily available then when top dressed. Of course the aeration and mixing you get with the pumps will break it down further activating enzymes and microbes but quite a few types of fertilizer don't really need it. It's always about what's most convenient for you and what the plants like. There's a million growers with a million ideas about the right way to grow who'll tell you their way is the only way. Plants are far more flexible then people.

As far as height control, I like to tie mine over. I try not to top whenever possible because you're removing the fastest growing strongest part of the plant. There's a hormone in ganja that tells it to send the most nutrients and vigor to the topmost part of the plant. The idea is to have as many nodes be 'the top' as possible. You end up with more tops faster then you do when you remove the top. Because the hormone is being distributed to the lower limbs immediately instead of waiting for the lower branches to get as tall as the top of the pinched plant. There's variation, some strains respond better then others the same way strains respond differently to topping. I've had success with sativas.

It probably won't help you with your rootbound problem though. You'll always need so much root space for however much canopy space is used. As growers reach limits of light, nutrients, and space it seems like root space is one of the most neglected and underrated needs. It's usually the first place growers try to cut when they start running out of space.

 

[ipchains]

Hi therevverend,

Thank you for such an elaborated reply. Your approach is very logical, should give better control over specific situation or needs. I like it even better since I grow 10-12 different strains at once (need to explore them all ). Main idea is to get as 'water-only' as possible (true water only ideally), but found out you can't go water-only with 20-25L (5-7 gallon) pots when you grow large animals. That's why I'm switching to flower beds with 300-350l (80-90 gsllons) for just 4 plants.

You're very correct comparing LST with topping. AFAIK Auxins are redistributed when breaking Apical Dominance of main stem and its even slower and more damaging stress-wise when you Mainline (multiple tops). Despite this, I choose to mainline because I have limited space but unlimited height and grow narrow and very tall plants with just 8 tops each 1.5-1.8m (5-6 feet) long . I hope it can be clearly seen in attached pic.

It may seem weird for an indoor grow, but when you have lots of light, nutrients and air (additional your point which rang true to me), indoor trees can happen and they get root-bound quickly. Until recently my grow environment was bottlenecked by lights and air and I was happily growing small bushes in the very same autopots.


Cheers!

 

[therevverend]

Looking good. Those are exactly the sort of plants that respond best to topping. Lucky to have plenty of headspace and air. Normally I make fun of growers who end up with 6 foot tall plants indoors, vegging their plants for too long, because the light only penetrates the top 1/3 of the plant. Not in your case, those sativas will stretch and stretch and stretch. I'm the same way when it comes to growing too many different strains, variety has it's own quality. Growing sativas ain't easy, not many growers do it and even less do it well.

 

[squatty]

What a beautiful hedge of plants ipchains. They remind me of bamboo.

 

[ipchains]

What a beautiful hedge of plants ipchains. They remind me of bamboo.

Thank you I have quite similar jungle feeling. Had an early repot and soil was stronger in Nitrogen than usual. Amending organic super-soil is still more of a guesswork than precise calculation (various dry amendments release fertilizers over-time at different rates) Nevertheless, they turned out quite well and yielded a lot, especially Super Malawi Haze in back

 

[CowboyTed]

ipchains, I can give you a couple suggestions for keeping the height manageable. I've tried two methods that achieve the same general result.

The first time I grew in a raised bed, I transplanted plants that were about two feet tall, and leaned them about forty-five degrees toward the north. This breaks apical dominance quickly and sends numerous tops reaching upward and southward. (I'm at 40 degrees north.) You can reach the same basic result by transplanting the plants standing straight, but immediately start pulling the stem downward, and repeat as it grows. You'll wind up with a plant that has a curved stem, and generally reaches upward with multiple tops in much the same way as leaning them over forty-five degrees when you transplant into the raised bed. In either case, you want to ensure that the meristem is not higher than the other branches in order to break apical dominance of the meristem.

With either of those methods, I also lollypop the plants significantly when flowering begins, clearing smaller branches and bud sites inside of the plant, along the lower and smaller stems. Doing this concentrates the flowering on the tops you leave, generally your healthiest and most vigorous branches. This lollypopping makes harvest much, much easier, as you get no popcorn and very few small buds - just a bunch of colas. My greenhouse plants last year produced about twenty colas each, and they were nice, fat colas, even the sativas.

I've grown outdoors in raised beds, and also in raisesd beds inside a cheap $100 greenhouse that's only seven feet tall. The simple greenhouse produces far superior bud, at least here, where high winds knock the branches together and damage lots of trichomes around the exterior of the buds. The greenhouse prevents that damage, producing better looking and stronger bud. Of course, the greenhouse also limits your height.

Here's a link to the sort of greenhouse I use. It seems to have doubled in price in just two years. It is still a bargain way to protect your plants from the elements.