Soil Recommendations for Autoflowers

Greetings everyone!

Beginner growers here! We’ve just sprouted four new autoflowers and we’re beginning to wonder if our soil mix is adequate as far as their needs go.

We’ve just recently had two plants fail to get past the seedling stage- they eventually drooped, yellowed and slowed their growth until dying.

Our stats as follows:

  • Strain: Gorilla Glue
  • Type (fem/auto/reg): Autoflowers
  • Climate (indoor/outdoor): Indoor
  • Medium (soil/hydro/details): Peat Moss, Compost, Perlite, Vermiculite
  • pH of runoff or solution in reservoir: N/A
  • Nutrient mix strength (EC/TDS): N/A
  • Light type & schedule: 18/6
  • Temperatures day & night: 22 C/25 C
  • Humidity day & night: 40%-60%
  • Ventilation: Yes
  • AC: No
  • Humidifier: Yes
  • De-humidifier: No
  • Co2: N/A

The soil we’re using is a combination we read about from a few sources on the web (Zambeza, GrowWeedEasy), and this is the part we’re really curious about:
3 parts peat moss
3 parts compost
2 parts perlite
1 part vermiculite

And that’s all that’s in it, no “boosters”, not extra fertilizer, nothing. We assumed the compost would provide all the nutrients they could need for the beginning stages, but they seem nitrogen deficient after a certain point. They’re doing okay for now, but we would hate to have the same thing happen again. We’ve been very careful with our watering schedule and we’re convinced this isn’t an over-watering problem at this point. They were germinated/planted at different times and are between 1 and 3 weeks old.

Last plants:

Current plants:

Are you using a dome over the top? That can help the seedlings. It looks like a plastic type pot. Do you have enough holes for drainage? Have you tested the soil’s/water’s PH? Those might be some things to check. You might try using a different soil ( like fox farms).You can always go to Robert’s grow Bible. If you haven’t you can download it from the ILGM website. Good luck, i hope you find out whats happening so you can get growing!

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We did, but took them off once they popped up. Should we keep them on maybe?
We have holes in the bottom of the pots and drilled some more too, bu we’re only giving them very little water at a time at the moment because they’re in such big pots. Our soil pH tester doesn’t seem to give us a readout for this soil (it’s VERY light and airy so it may not get a reading), but the water we give them is always around 6.5.

We’re stumped, but definitely considering trying a fox farms soil next time or something with better nutrient makeup. Would it help these plants to add some of this to the current soil? Right now we’re trying to find amendments that may help what seems to be be very dull soil more nutrient-rich.

Thanks so much for your help! :slight_smile:

I think if you try a lot of different fixes you won’t know which one helped. I would keep the dome on them a little longer. I am a newbie myself so I am hoping some more experienced growers can guide you on soils and such. I grew mine in a pot for pot’s soil. Bergmann soil is good, but i am not sure he has any. If these fail I would try a different soil. Maybe start it in a starter coco wafer, and hold off transplanting until the third set of leaves are the same length at the second set. Good luck!!!

You’re probably right, we’re planning on just doing a thing at a time and seeing how they do from there. It should be noted we are actually in Australia, and Bergman’s line of soils and fertilizers isn’t available to us down here (as with Fox Farms, as we’ve delightfully found out :upside_down_face:). Very hard to find out what good soil is down here, lol!

Thanks so much for your tips either way, we’ll try this. Will post updates if they improve! :slight_smile:

If none of the commercial soils are down there then there are plenty of “recipes” for making your own soil.

seedlings shouldn’t need any nutrients. If you can’t check the soil’s PH, i would try to find a way to do that. If you can’t do it maybe take it to a garden store and they could test it (and sell you the tester they used so you can do it from now on). I am guessing this is soil related, but thats just a guess. Find the problem. Then go from there. You might try taking your ph tester to a store to make sure its working properly.

From the grower: Our soil pH reader gives us a reading from 6.0-7.0, is this okay? We make sure all of our water is around 6.0 to 6.5. We’re using 600w MH lights about 4 feet, and we’ve put them straight under these since planting them, final pots and all. Should all of this be adequate?

The other question we’ve had is our soil. We’re using a 3 parts peat moss, 3 parts compost (pine bark), 2 parts perlite and 1 part vermiculite in 3 gallon pots.

If any of this seems amiss please let us know!

6-7 is ok at this point. When she gets to veg stage anywhere between 5.9 and 6.5 is fine. If your organic anything just below 7 is fine (6.5 to 6.8 or 6.9). You will need to monitor temp and humidity. The humidity you listed early on is OK. I shoot for 50% during vegetative stage and a little lower at flower (35-40%). I have never used that soil formula before. Your plant will tell you if she isn’t happy. From the sound of it, does your dry out quickly? That can make things a little tough. But you have the perlite and vermiculite. Maybe someone with more soil experience can help with that. Your plant will let you know if something is not right. Everyone here can help if you run into problems!

Yes- seems to dry out rapidly! We’re really scared to overwater them, but the moisture disappears so quickly we feel inclined to. “Dry up to an inch” or “dry on top” would be an understatement- after a couple hours, its bone dry as deep as we can feel :confused: is this bad?

You need the soil to retain some moisture. The dome will help keep some of that moisture in. You may just have to mist it pretty often. With seedlings I was using a small syringe to water mine. The roots are still tender and developing at this stage. If you can find some better soil you could transplant. Just wait til her third set of leaves are the same size as the second set so you don’t stress the plant too much.

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We’re considering that, a change of soil definitely seems to be in order.

We have yet to actually see a third set of true leaves on any of our plants, they seem to run out of something after barely becoming sprouts before just slowing growth to a halt and turning yellow. This all seems to go back to the soil, and I’m sure they’re not getting something they need from it, be it moisture retention or nutrients.

Will try to keep them domed until we can instate something more permanent!

I will keep my fingers crossed, good luck!

Any progress reports?

Any news to report?

There is! These seedlings have since damped off, the same way the others did, but since that we have completely changed our approach.

We got a propagation tray with a lid and switched to Rockwool cubes for the seedling stage, and this has changed EVERYTHING:

As you can see these are very different plants from the ones we were growing before. These were started in paper towels and dropped into Rockwool after their tap root emerged and I’d highly recommend this method. Today they’ll be 1 week old, and these seedlings are taller and have grown faster than anything we’ve grown before!

I’d chalk this up to not planting your seed into their first big pot right away. Too much space. Were also switching to coco coir and perlite instead of soil, because soil is too hard to water correctly, especially in the early stages. These will be going in their cubes into their final (3 gallon) pot of coco coir/perlite and receive nutrients about a week after that.

Please let me know of any other takeaways we might get from this. I wish all beginners knew what we know now, but this kind of stuff just isn’t explicitly said anywhere online, so I hope other beginners see this!

Thats why this group is so important to new growers like you and me. I tend to read a lot of posts because I can learn so much from them. In my experience books have suggested many different ways to do something, which can be confusing at times. With this site, everyone pretty much agrees on what you should do and what the problem is. Earlier today I asked if it was ok to partially harvest a plant. I have some buds that are almost ready, while others need more time. I found out that I could take the ones that were ready and leave the others to mature. This was my first “official” grow. 40 years ago we tried planting some and had no clue what to do. I come from a place where “it” hasn’t gotten here yet, and I really doubt its on the way! We just took a few seeds from a bag and planted them. One did really well, and became a problem. It became visible from the street on top of our house! Anyway, this is a great group of people from all walks of life and ages. I am so glad that things are working out for yall. I figured they would. If you have any problems just reach out, and let me know when harvest is! I don’t know that much but I will always help. If I don’t know the answer I will call the more experienced troops in to help. Here’s a pic or two of my blueberry girl. Happy growing!

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It really is a great community and resource, there’s so many changes and improvements we’ve made because of the input here. Even this, about the “take some and leave others” for flowering, is something I didn’t know before and will be able to employ now! We can’t wait to finally get past this stage, and hopefully have problem plants like this :sweat_smile: our location is very low-key and we’re in a great place to grow whatever we want as long as it’s not outside, so hopefully we can get there.

I’ll no doubt be back here as they come along, and will try to update on the progress of our newest additions :slight_smile: thanks so much for your help!

No problem. Just paying forward what I have learned from others.