Seasol on Cannabis


Hi All,

Just seeing if anyone has used or is using Seasol on a regular basis on their plants? Since it isn’t a fertilizer and has hardly any NPK rating (it is a soil tonic) I don’t see the harm in using it, however I am vary since it is my first grow, on using it on seedlings.



hi @revhead.i use it all the time on my outdoor plants as a soil drench and a foliar spray . I also add it to my compost teas. Like you said its more of a tonic than a fertilizer With that being said I do only use at around half the strength suggested on the label. Its also usefull to help minimze shock when transplanting.It does contain some potassium so good for use during flowering as well. Good luck with your grow.


I’m only doing my first grow of autos and have used it from two weeks on , just know from other domestic gardening duties it performs well,so see if you agree my girls at just over eight weeks old and looking very healthy,been problem free so I will continue using in every feeding brew I create , cost is minimum for results I think.


Good to hear your take on seasol, while I do try to keep fertilising to 75% dosage rates (lately 90% plus), seasol 90% dosage rate , can you use seasol in a grow tent with soil as the medium? I did find a hydroponic fertiliser calendar for autos here and tried to convert basics to outdoor grow with encouraging results,however getting grow tent for next round and was hoping to replicate what I achieved here with the same fertiliser brews , any advice would be appreciated.


Go for it @Fabes, If your using soil as your medium I really dont think using it indoors will create any issues, btw your plants look great. keep doing what you are doing. Good luck


Thanks @mountainman1!

I have about 6 plants going and all but one is in seedling stage. I have added a 1/2 dose to my 500ml spray bottle which i use to mist the plants. Hope I aint doing it any harm!

How often are you using the Seasol?


They look awesome @Fabes!! What strain? How often are you giving it seasol? Dosage as per bottle or less?


@Fabes Are those Autos an outdoor grow? They look amazing!


Amnesia Haze,Northern Lights and Blueberry (ILGM AUTO MIX PACK) , outdoor grow from two weeks, being first ever grow and inundated with conflicting information and the fact they were so tiny to put out in the wild,however the latest two had a small feed at one week and released into the wild,guessing around three times bigger than first batch,so will be interesting to see if any big difference in yields. Have used Seasol from early on at around 70% - 90% and a few other fertilisers varying from 50% - 100% (can’t help myself as in the beginning told Autos don’t like heavy feeds especially) ,but pretty much debunked that theory, wether that has been helped by using Seasol I don’t know,all I know is that plants are healthy,other domestic gardening has always shown good results,all fertiliser brews I make up are just administered directly onto soil to save time,as neighbours probably think I’m special already having coffee and conversations with my girls several times a week, just very therapeutic both ways.


LOL Mate that is awesome!!

Tell me about all the conflicting information! I just started using the seasol and using Charlie Carp as the fert as half strength. I put a bit of sealsol in my mister to use as a foliage spray. It is spring here in Aus, but here in Sydney, we have had solid rain for the past 2 weeks. I want to put my plants outside to take advantage of the sun.

This is also my first grow and I think I am like a hover parent. Worried I am giving it too much love!

I note you are using LST.

The plants look really healthy! Good luck with the grow


Well been pretty dam wet up here in Brisbane too the last few days, which coincided with non fert watering cycle (every watering/fert has Seasol) but am happy to let nature run it’s course this time, trouble is very important to get soil near dry before feeding/watering again (as from five weeks I started flooding pots as to 80% saturation because they sucked it up in no time) , a few more days of rain forecast so probably fert them wet after draining what rain water I can and hope for sunshine. Not sure if I can post picture of fert brew I use but a one stop shop at Bunnings will see you out with minimal costs leaving you only in need of a flush additive for the last week of plants lives (usually two flushes and after second flush a 1/4 inch drilling approximately 15mm up from soil and then another 15mm from that at 90 degrees to first hole) ,apparently enables extra juicy buds to form. I’m probably going to cop a bit flak here for giving you my say (as this my first ever grow since being a teenager with bugger all knowledge and eleven plants in Mums greenhouse that by the way was some of the nicest smoke I’ve had,fluked it by being impatient), so will give you my advice and later give you link that has a few Gun Auto growers posting in it that you can research and gain knowledge/answers as my head was spinning trying to keep up to the fast paced Auto life cycle.
Definitely recommend a small feed at one week of age (approx 1/5 strength of manufacturers directions including 1/2 strength Seasol and 1/5 strength growth stimulate),get them out into the sun at this time with a cut off soft drink bottle over them (cap off on top as must breath),alternating one feed then one water at around 80% saturation (usually 2-3days between depending on your specific grow location),yes you see little plants getting little watering but you want to get that Seasol into soil so when plants start to root they are in a very accommodating soil mix,I also mixed some charcoal in medium as thinking another helper for good health. Gradually increase % of fertiliser etc to 75% by week four,keeping vege mode going till week five/six before transitioning over to full bloom week seven/eight (different varieties,different times,that is where you will have to use the Force),I have used LST on all as it makes sense to me from what I’ve read,however the proof still needs to be seen but have multiple bud sites developing just hope I have to strap them to the scaffolding or I’ve wasted $30 believing big juicy buds are coming my way,hope this gives you a bit more confidence as it’s all a learning curve,just wish Australia could become a happening country and let me spend more time in the garden, can’t beat that beautiful sunshine.


Hey@revhead, I pretty much add a little splash to every other watering. Always put some in my compost teas. I also use when transplanting.


@revhead just have read through that post and you’ll see a few Gun Auto growers with a wealth of knowledge, start reading their other post and try to keep it in your :exploding_head:, you are on your way, hope you see sunshine soon ~


Thanks Mate!!