John Innes growing medium

[disco survivor]

After my disastrous last grow (appears I created a toxic, over fertilised, incorrect pH growing environment in the soil), I'm going to stick to the stages of the John Innes compost growing method for my next grow. For those in the USA or not familiar with John Innes, look up "The John Innes Centre".

 

I've been growing fruit and veg outdoors/ under glass for over 30 years but never in an artificial indoor grow tent environment and that's what I'm struggling with. 

 

I've germinated in John Innes No1 and recently transplanted into larger pots with John Innes No2 compost. 

 

Apart from 1 plant, all looks to be very healthy and without doubt the best start to an indoor grow I've had to date (plants are about 3 weeks old (from initial germination).

 

I'll start a grow diary to plot my progress and as usual, any advice will be greatly appreciated

 

I have already made a big mistake though. As my grow tent is 2m x 2m, I thought it would be a good idea to fill the gap with 3 plants from the garden. Although I sprayed the plants with bug clear, I have noticed some insect activity in the tent (not a lot but enough to get slightly worried). In future, plants that are not germinated in the tent will stay well away from it 

 

[Boojum]

I'd advise getting a very fine sprinkler head for watering when using John Inness, in my experience (using John Inness #3) if you water it too heavily it has a tendency to set like concrete.

[SkyRider]

1 hour ago, disco survivor said:

After my disastrous last grow (appears I created a toxic, over fertilised, incorrect pH growing environment in the soil), I'm going to stick to the stages of the John Innes compost growing method for my next grow.

 

never in an artificial indoor grow tent environment and that's what I'm struggling with. 

 

I have already made a big mistake though.

 

 

As said above, straight John Innes is not ideal to grow ganja in. Been there, got the t shirt. You'll make it to harvest, but you'll find much better results with a better soil.

Sounds like you've had a nightmare with soil so far, so crazy idea, but why not start with some actual cannabis soil you know will do the job? Plant Magic, bio bizz, whatever. They are all tried and tested.

 

And as for Bug Clear... Well at least you are honest. No offence though, I wouldn't be smoking that weed now. To each their own i guess.

[kc stoner]

Have you removed the outside plants 

[Hazeworks]

I won't be growing in old potato compost again

[Boojum]

I've tried all kinda of non weed specific composts (including John Inness) but I've had by far my best results since I switched to Plant Magic Plus (and I mean by far). Perhaps some of that is down to me having learned from my mistakes etc, just getting better at this gorwing lark, but I'm sure the change in compost has helped.

[disco survivor]

11 hours ago, kc stoner said:

Have you removed the outside plants 

Yes. Won't be doing that again. I'm also going to buy separate tools specifically for the tent and not use the ones from the greenhouse.

[disco survivor]

1 hour ago, Boojum said:

I've tried all kinda of non weed specific composts (including John Inness) but I've had by far my best results since I switched to Plant Magic Plus (and I mean by far). Perhaps some of that is down to me having learned from my mistakes etc, just getting better at this gorwing lark, but I'm sure the change in compost has helped.

Found a hydroponics shop local to me yesterday and purchased some plant magic nutrients. I'll be using Plant Magic Plus for my next grow, thanks. 

[disco survivor]

Thanks for all the great advice as usual. Things I'll change for the next grow:

1) Will use Plant Magic Plus growing medium

2) Will use Plant Magic nutrients

3) Separate tools, containers and watering can for the tent grow with no cross over from the greenhouse equipment

4) I'll be sanitising the tent before any further grows take place.

[BilgePump]

Have a look at Jiffy pro media, it's fantastic and cheaper than most professional composts

 

Edited August 22 by BilgePump

[Crow River]

Everyone has their own experiences. Like you I'd been growing fruit and veg outside for years, tending houseplants, etc. I started off using John Innes No.1 for seedlings, and while it worked I now use a mix of compost, 30% coco coir and a bit of perlite for drainage. I've had success with Westlands peat-free compost with added John Innes, it's my main choice now for indoor grows, absolutely swear by it. I've used it in the greenhouse too, along with home made compost, bog standard supermarket compost, etc. Over the past couple of years I've found it useful to add about 30% rehydrated coco coir, previously I added vermiculite and perlite. I sometimes still add about 10% perlite. The coco coir makes for a slightly lighter, fluffier potting mix. 

 

I would add there's no harm in re-using compost from your grows. I let the pots dry out after chop, then remove the main stem/root mass and store the used potting mix in bags. I then add it 50/50 to fresh potting mix, usually for outdoors/greenhouse but sometimes for potting up young plants indoors. Sometimes sterilise beforehand with peroxide just in case, sometimes not.

 

I've never used specialist canna soils or nutrients, and apart from some root boost stuff I bought on a whim last year, probably never will. As long as the medium is reasonably free draining, cannabis will grow in just about anything...

[Hazeworks]

I was thinking of try Dalefoot sheepwool compost next year 

[geoffo]

I mix jon innes with canna terra. Or used too. After 25years ive a big heap in the garden that i reuse after its rested n rotted the old roots away. I sieve any leftover roots out.

works superb probably because its well colonised with bennies i orginally used.

I run to waste about 20% more volume than needed each watering so dont get salt buildup.  Ph n use nutes every 2nd watering. The plain water i use inbetween lets ph move up allowing other nutes to become more available.

I use the jon innes 1 and 2, the 3 i found a little high in nutes it didnt burn the plants or anything just grew a bit more stem than id like ideally

[SkyRider]

4 hours ago, Hazeworks said:

I was thinking of try Dalefoot sheepwool compost next year 

 

Expensive but very nice and at least you know exactly what is in it. Kinda like buying the organic, fair trade, we put them in mansions type shit from the supermarket. Is it worth the extra? Probably not, but it is very nice.

[disco survivor]

Appreciate the negative comments about John Innes compost but I have to also go off my own experience and up till now, I'm very impressed with the healthy look and growth of this latest attempt. 

 

Still a long way to go but for half the price of growing medium specifically targeting cannabis growers, I'm very impressed.