How To Make Potting Soil Mix For Container Gardening, Self Watering Pots, Grow Bags And Soil Blocks

In this video I show how I make potting mix. This peat-based mix works great for all types of container gardening, as well as for making soil blocks. It can be used for regular pots and also for self watering planters, wicking beds, and grow bags. The mix is based on Elliot Coleman's soil blocking mix, but scaled up, and with some adjustments.
Feel free to share this video with anyone who may find it useful.
Correction: 2:47 If you are using a bale of compressed peat like I have in the video, it expands to more than 3 cubic feet. For 3 cubic feet of compressed peat you should add 2 cups of dolomite, instead of 1.5 cups of dolomite.
Here are links for many of the products I use in my vegetable garden. Note that a lot of these items, like the fertilizers and the trays/saucers, have gotten much more expensive lately (like everything else). I shop around to find the best prices on the items and if I can't find something at a reasonable price then I will just do without or find a substitute):
7 Gallon Grow Bags: amzn.to/2XaJ1mp
5 Gallon Grow Bags: amzn.to/3ht2wNP
10 Gallon Grow Bags: amzn.to/3k4WpkB
14 Inch Diameter Grow Bag Trays/Saucers: amzn.to/3tAkzqc
16 Inch Diameter Grow Bag Trays/Saucers: amzn.to/3AiP724
Sustane Organic Fertilizer (4-6-4) 20 lb Bag: amzn.to/3lztPHJ
or
Jobe’s Organic Fertilizer (4-4-4): amzn.to/3EdxeV2
or
Espoma Organic Fertilizer (3-4-4): amzn.to/3EbvJ9P
For Berries: Espoma Berry-tone Organic Fertilizer (4-3-4): amzn.to/3jlD8dA
In addition to the above fertilizers I occasionally use these seaweed and fish fertilizers to give my plants a boost of nutrients. I also use some of the seaweed fertilizer (half-strength) on my seedlings right after I transplant them (Note: I don’t use fertilizers with fish in them for seedlings):
Maxicrop Seaweed Fertilizer (Powder): amzn.to/3uWO9ak
Maxicrop Seaweed Fertilizer (Liquid): amzn.to/37uA0JJ
Neptune's Harvest Tomato & Veg Fertilizer 2-4-2 (Note: this formula is best for first few weeks of plant growth, as it encourages lots of green leafy growth. For fruiting/flowering plants, I switch to the Rose & Flowering formula after the first few weeks. Also, this contains fish and the smell attracts animals, which will dig up the plants trying to find the source of the fish smell, so I use it early in day and water it in just before dark to minimize the smell). amzn.to/3r8OJ40
Neptune's Harvest Rose & Flowering Formula 2-6-4 (Note: this formula is best for later stages of plant growth to encourage more flowers and fruit to grow. This formula also contains fish so everything I said above about attracting animals applies to this formula too). amzn.to/3KqBino
The Following Organic Soil Amendments Add Trace Minerals To The Soil.
Green Sand (Organic Soil Amendment Adds Trace Minerals): amzn.to/3z5uG7B
Kelp Meal (Organic Soil Amendment Adds Trace Minerals): amzn.to/3tz2lFH
Dolomite Lime: amzn.to/3CbclIl
Self-Watering Grow Boxes:
Patio Pickers: amzn.to/3vrhHhW
or
Earthbox: amzn.to/39VfsaX
Row Cover (This is a multipurpose plant covering that can protect plants from insects, provide some cold protection in winter, and can also provide a small amount of shade): amzn.to/3nreXh5
Drip Irrigation: amzn.to/3uzbhuV

[@gidget8717]

When I lived in Virginia and used to mix large batches of soil mix, I bought a cheap blue square tarp spread out my peat then my first layer. I mixed them together by picking up one corner and tumbling the content back toward the middle. After lifting each corner, I would take the back of a garden rake or a hoe and spread it back out and add another layer of amendment, tumble it back to the center and repeat. As I aged it was a lot easier on my back than being bent over turning it with a shovel. 😁👵

[@floridavegetablegardening]

Thanks for the tip! I will try that next time 🙂

[@kismyc0untryazz-491]

I have a LOT to mix today. You just saved my back, I can't thank you enough for this wonderful idea!

[@kgille]

My sister and I just mixed up this amount of soil and found that your method worked great and didn't even take very long. We were surprised at how well it was mixed. Much faster and easier on the back than using a shovel.

[@jimcasher3257]

I use the same method with great success with my aging back.

[@samueljaramillo4221]

Good mixture. Pretty similar to the mix I do.

[@SrSrk98]

I do my mix on a large blue tarp... mix well and spread it on the tarp to sun dry for 3-4 hours... so there is no wetness.. and then I store it in large bins...in my back porch... works good.. no fungal after effects:) I also mix some sun dried coffee grounds which I collect in old coffee tins...and also mix some paper shreds from the shredder...for volume...

[@floridavegetablegardening]

@@SrSrk98 good ideas! I will have to try adding paper shreds.

[@stanceonlife7883]

Great informative video! One note, the 3 cubic feet of peat moss you have is compressed(I have the same one). Web says it can expand “up to 6 cubic feet”. Something to keep in mind to anyone who gets non-compressed peat moss following the recipe mix.

[@floridavegetablegardening]

Thanks! And thank you for mentioning the compressed vs not compressed peat. I’ve only seen it sold in the compressed bales so I didn’t think of that. I will put a note about that somewhere when I get a chance. Thank you! 🙂

[@heathermichelle8187]

I’m so glad you said this!!! I was just about to go to the Farmer’s Exchange to buy more when this comment made me double check! I’ve never seen this mentioned on ANY of the big channels!!!

[@dasanchez1979]

I also found this same info to be true on the Lowes website of this exact Peat Moss. If this is the case, should more Dolomite Lime be added ? Then again, this is the mix you've been using with great results, I assume. Maybe it's just right. 😊 Have you tweaked it since then?

[@floridavegetablegardening]

@@dasanchez1979 Hi! Yes this is still the same mix I have been using and have had good results with. I always have used the compressed bales from Lowe’s and Home Depot and I had never realized that this says it expands to more than 3 cu ft. If I had realized that then I would’ve been adding 2 cups of lime instead of 1.5, but it has always worked out well anyway. I do add around a half cup of extra dolomite to my containers whenever I’m potting fruiting vegetables like tomatoes, peppers, cucumbers, or squash, but I don’t add any extra dolomite to my pots of lettuce or berries. Berries like slightly more acidic soil so too much dolomite could be bad for them. I should have given the peat/dolomite ratio like this instead: 1.5 cups of dolomite for 9 * 10 quart buckets. I hope this makes more sense.

[@TheJademaxus]

Thank you for the comprehensive guide!

[@floridavegetablegardening]

You’re welcome! 😊

[@tomdifazio9895]

Great video I’m going to try your mix this season

[@1cleandude]

Awesome job I wish I knew where you live so I could come help you!🙏🙏🙏

[@charleywalker2982]

Thanks for sharing your knowledge and keep your videos coming please.

[@floridavegetablegardening]

You’re welcome! Thanks for the encouragement! 🙂

[@daveschreiner413]

Nice mix! Thanks!

[@floridavegetablegardening]

You’re welcome 😊

[@nancytharp8213]

Thanks for sharing 🙏 😎 🏖 🏝

[@floridavegetablegardening]

You’re welcome! 🙂

[@jonnyhawt8973]

Well done!

[@floridavegetablegardening]

Thank you! 🙂

[@crisl9079]

Thank you for this. I’m in SWFL and it’s nice to see how-to’s for FL gardeners as gardening down here is definitely different than gardening anywhere else. I find my biggest problem is the humidity/water retention in my containers… the TOP of my 5 gallon buckets can be dry while the bottom 1/3 is wet with algae growth on the side-even with like 10 1/4-1/2 inch drainage holes in the bottom AND sitting on elevated bleachers! Any thoughts on why and what I can try to remedy that?

[@floridavegetablegardening]

You’re welcome! Is the water retention in your containers hurting the plants? As long as the top is dry, I would think the plants wouldn’t drown. Some containers are actually designed to hold water in the bottom and they can work well for some types of plants. However, I am surprised that yours are not draining even with holes in the bottom. Are you using a potting mix for your growing media? Potting mix is what works best for containers. Other potting soils or straight compost could potentially retain too much water. I would try adding a few more holes around the sides a couple of inches up from the bottom and see if that helps. Also, I don’t know what kind of surface the bleachers have but perhaps they could be blocking the holes so they can’t drain? You could try putting some bricks or something under the outer edges of the buckets to raise them up off the bleachers so that the holes won’t be obstructed if the bleachers are currently covering the holes. Good luck!

[@crisl9079]

Thank you. They don’t drown per say, but end up with fungus of some sort and algae growing around the inside of the bucket. I have used a variety of container mixes from store bought mixes for containers to recipes I found online I mixed for myself. I will try adding more holes and a few higher up as you suggested and appreciate your feedback. Do you think upping my amount of perlite in the bottom half of my containers would help them drain any better?

[@floridavegetablegardening]

@@crisl9079 yes I think adding some extra perlite could potentially help. I’d try it in at least a few of your containers to see if it helps.

[@crisl9079]

Ok, thank you for the feedback…I will give it a try.🙂

[@floridavegetablegardening]

@@crisl9079 You’re welcome. I hope that will help.

[@SouthFloridaSunshine]

I am in 10b Palm Beach County, great video and information! I can’t bring myself to use any mushroom or manure based compost due to the grazon problem spreading even into some commercial mixes. Otherwise, I loved every bit of this except that your neck hurt. ❤️

[@jonnyhawt8973]

I could be wrong but I think the black cow compost from lowes/home depot has to be a certified manure without grayzon. I've used it for many years and haven't had any bad experiences. I'm very cautious to use any other source of manure because chances are it has some herbicide in it.

[@floridavegetablegardening]

Thanks! That’s scary about the grazon spreading into commercial mixes. I knew it was a potential problem with getting manure from horse stables but I hadn’t heard about it being in commercial compost. I really wish the hay companies would have to disclose whether they used it in their fields. I’m really skeptical about it being safe to feed to animals in the first place. It’s so hard to know what you’re getting. My Mom has a horse and we are even cautious about using her manure because we don’t know if it could be contaminated with grazon. So far I haven’t had any problems with our horse’s manure or the bagged compost but I still worry about it. Thanks for the heads up!

[@floridavegetablegardening]

@@jonnyhawt8973 I use black kow a lot too and so far haven’t had any problems with it either. I hope you’re right. I will look into whether they certify it to be free of grazon.

[@jonnyhawt8973]

@@floridavegetablegardening With all your hard word that would be devastating if it happened. Mixing up that potting soil is a lot of effort but like you said it's much cheaper and really a better product in the end. I've been lazy and just buying the bagged stuff but watching you do it inspired me to put in the effort.. Your Mother's horse is a great resource to have. I have a neighbor with a horse and I get it's manure without the worry of any herbicide. Crazy world we live in where there's so many variables of things to have to look out for. Happy Gardening! 😊

[@floridavegetablegardening]

@@jonnyhawt8973 yes I would be very upset if that happened. Thankfully it hasn’t so far. Maybe I will start testing my compost by planting a few fast growing seeds in it before I mix it in with everything else. Yes I love having a horse on the property (for many reasons). We always test the manure first in areas that don’t have anything important growing and so far it’s been fine so hopefully it will stay that way. Thanks! Happy Gardening! 😊

[@floridacritter]

this is great! thank you! :)

[@floridavegetablegardening]

You’re welcome! 😊

[@Sullfla]

Hi Elizabeth, I have been watching your videos which I really appreciate. I have my tomato seedlings growing inside, and want to transplant them soon. What size grow bags would you recommend❓What vegetables do you prefer to grow in grow bags❓ Wouldn’t the biggest grow bags work for most or all veggies and tomatoes? THANK YOU‼️

[@floridavegetablegardening]

Hi! I’m glad you’re enjoying the videos. For tomatoes I would use a 7 or 10 gallon grow bag. I usually put them in 7 gallon bags. I use them with trays underneath during dry season so that they don’t dry out too fast. I don’t know if you saw this video yet, but it shows me transplanting tomatoes into 7 gallon bags and I showed the trays I use at the end. You could also use plastic liner instead of a tray to hold some water: kzbin.info/www/bejne/Y5_YiKOnq9aep7s I mainly use grow bags for tomatoes, peppers, cucumbers and strawberries, but I also use homemade “self-watering” style 5 gallon buckets for my peppers and cucumbers, so I don’t exclusively use grow bags for everything. You can grow pretty much anything in the grow bags as long as you use the right size bag for each individual crop. The only thing I didn’t really like growing in the bags is zucchini/squash. They need a really big bag - at least 10 gallon, and they still do better in the ground.

[@ronm6585]

Thanks.

[@floridavegetablegardening]

You’re welcome! 🙂

[@plu2601]

Thank you for the video and detailed explanation! Can I substitute perlite with play sand?

[@teresaholland4790]

Rain in Florida 🤣I live in central Florida we get a lot of rain

[@whodidit99]

Ratios would be very helpful.

[@saimaakter9488]

Very nice and informative video. I have a questions, i live in texas, where temperature is very high during summer, i want to grow vegetables in container in my backyard, so is this an ideal recipe for potting soil? What about black cow brand manure? Some says it's very good for plants. Please help me with your advice. Thanks❤😊

[@floridavegetablegardening]

Hi. Thank you. Yes, this is a great recipe for potting soil for use in containers. I use it to grow vegetables in containers and it works very well. Yes, Black Kow brand is a good one. I use it a lot and have used it in my potting mix with good results. However, high summer temperatures can be too hot for a lot of vegetable plants even if you grow in good soil. I don’t know how it is in Texas, but here in Florida, we don’t grow many common vegetables during the summer because it’s too hot for them here in summer. For example, lettuce gets bitter in hot weather and will quickly go to seed, so in Florida we grow lettuce in the fall, winter and spring, but not during the summer. I would suggest checking online for Texas planting guides that tell you the best times of year to plant your vegetables, so that you can avoid planting crops during summer that might not do well in the heat. I would follow recommendations like this for Texas: aggie-hort.tamu.edu/archives/parsons/earthkind/ekgarden14.html Happy Gardening! 🙂

[@saimaakter9488]

@@floridavegetablegardening thank you so much for your wonderful advice😊😊😊

[@littlemissy8356]

If you mix the soil that you are making with the dug up soil you won't need to use lime.

[@jackiekreuzer4008]

What would you do different for strawberries, if anything.. Very nice video.. I just found your channel..

[@floridavegetablegardening]

Thanks! I don’t do anything differently for strawberries (except I usually use a berry fertilizer when I plant them). I have used this same mix for strawberries and it works well. If you wanted you could add more compost to the mix, but you don’t have to. Good luck!

[@jackiekreuzer4008]

@@floridavegetablegardening Thank you..

[@floridavegetablegardening]

@@jackiekreuzer4008 you’re welcome!

[@traceybier1128]

Wouldn't coconut coir be a better resource than peat?

[@tatertotcountry]

This fantastic. Thank you! ---- I'm growing cucumber with the, so 6.5 would be a good ph to my knowledge. I have the same lime that you have. Would 2 cups be enough to make the soil a little less acidic? Does that sound reasonable? Or more?

[@floridavegetablegardening]

Adding two cups to the overall mix is probably enough to make the soil alkaline enough for cucumbers. However, when I plant cucumbers (in 5 or 7 gallon containers), I always add 1/2 cup of dolomite to my potting mix in addition to what I added to the main batch. So this would be an additional half cup in each 5 or 7 gallon container. That may be much more than necessary, but I use self-watering/wicking style containers for my cucumbers, and I got the idea from Earthboxes, which tell you to use a lot of dolomite (for the calcium and magnesium more so than the pH). I don’t use quite as much as Earthboxes do, but I use a fair amount to try to prevent blossom end rot. This has worked really well for me. Perhaps you could do an experiment and mix up a big batch using 2 cups and then when you plant your cucumbers try planting with varying amounts of additional dolomite. If it were me I would try some with no additional dolomite, some with 2 tablespoons of dolomite, some with 1/4 cup and some with a half cup and see which ones grow the best. You can see how I plant my wicking-style containers in this video: kzbin.info/www/bejne/Y5_YiKOnq9aep7s I plant all of my tomatoes, peppers and cucumbers in containers the same way. I have been working on a video to show how I make the 5 gallon self-watering containers that I like to grow cucumbers in, and how I prepare them for planting, but I haven’t had time to finish it yet. In the meantime, the tomato planting video might be helpful for you to see what I do. If you do an experiment with the dolomite, I’d love to know how it turns out for you. Best of luck! 😊

[@tatertotcountry]

@@floridavegetablegardening Thank you so much for the info! I have some pulverized dolomitic lime, so I was planning to raise the ph using that because it seems to me like it would change to ph more quickly, as I would like to get started with it. I also have that same bag of garden lime that you use. It is granular, with all sorts of nice nutrients in it too! I'll do some testing on the ph at different levels and let you know. Thanks again. Your channel is invaluable.

[@flat6fever680]

Liked and subscribed and thanks for sharing. Have you ever tried using some finely chopped pine bark in the mixture or do you think that is a bad idea?

[@floridavegetablegardening]

Hi! Thanks so much for subscribing! I have not tried using finely chopped pine bark in my mixture, but I think it would be worth experimenting with, depending on what you’re growing. I have used it in store bought mixes for tropical houseplants that like chunky mixes (like orchid potting mix for example). However, the big batches of potting mix l make in the video, I use for vegetable plants and also for making soil blocks. I don’t like to have chunks in the base mix because it isn’t good for making soil blocks, but I would consider adding pine bark to my base mix for use in pots. From what I understand, pine bark helps the mix to be light and aerated, which is good, but it doesn’t hold water very well. That can be good or bad depending on what you’re growing. I use a lot of peat moss in my mix and peat moss does hold a lot of water. Most of my container grown vegetables are in grow bags, which can dry out quickly and my vegetables need a steady supply of water, so I like using the peat that is light and has good water holding capability. I hope that makes sense. I think it would be interesting to experiment with adding varying amounts of fine chopped pine bark to your mix and comparing the outcomes. Good luck! 😊

[@flat6fever680]

@@floridavegetablegardening Makes sense to me. Worth noting is that I have recently un potted around 100 small trees and shrubs and am shocked at the difference in potting mediums and their water holding qualities. I see pine bark in all of them but some are heavy on the pine bark (fine chopped) and stay very dry and get so root bound that they won't even accept water. For those I had to remove the containers and pre soak the roots in tubs of water periodically until I could plant them and again at planting time. Now some other ones I had were root rotted and soggy with a very dark compost and just would not dry out at the bottom. Poor root development. I got some of those in the ground already and many more need to be planted soon. Those had some pine bark but not much. In this case, I'd much prefer the ones that were heavy in finely chopped pine bark and root bound.

[@nyc5898]

If I can't find compost, can I use humus and manure? And can this mixture be used for potatoes?

[@floridavegetablegardening]

You can use composted manure and humus. I have never used manure that hasn’t been composted, but it’s possible that manure that has been aged for 6-12 months might work. I would do some research on using non-composted manure before trying it though. These days I hear a lot of horror stories about people accidentally killing their plants with manure or manure compost that has herbicide residue in it. Because of this, I always test out any manure compost before I use it. I test it by planting some cheap, fast germinating seeds, like beans or peas, directly into the manure compost and see if they germinate. So far, I’ve never had a problem getting seeds to germinate in any manure compost I have tried, but if I did then I wouldn’t use it on my plants. Yes, this mix would work well for potatoes. 🙂

[@nyc5898]

@@floridavegetablegardening thank you so much. I'm new to this. All I can find at home depot is the bag of humus and manure. They don't carry anything else.

[@ML-ks2lj]

I'd imagine your boots might bring those nematodes in as well?

[@floridavegetablegardening]

Yes shoes can certainly spread the potentially nematode infested sand around. I try not to walk in the potting mix to avoid that.

[@stoicbreathe]

There is no perlite where I live, can you recommend something to replace it with? Thank-you

[@floridavegetablegardening]

You could use vermiculite or pumice or horticultural grit as a substitute for perlite. Pumice is actually probably better than perlite. I’ve also heard about parboiled rice hulls being a good alternative but I don’t know where to find it. Good luck!

[@stoicbreathe]

@@floridavegetablegardening There's pumice and rice hulls where I live. How very sweet to reply with such helpful information. You made my day!

[@floridavegetablegardening]

@@stoicbreathe Great! 👍😊

[@onLYbyM]

Washed sand (wash it once or twice to make sure you removed excess salt)

[@leeannmoore3158]

I wonder if you could use a compost tumbler to mix the ingredients?

[@floridavegetablegardening]

That sounds like a really good idea. The only potential problem is that you would still probably have to break up the chunks of peat and compost first, but it does seem like that would help with the mixing. Thanks for the good suggestion!

[@debbiebridges6350]

I have 3 cubic feet of compressed peat moss should I use only half for the recipe?

[@floridavegetablegardening]

No. 3 cubic feet compressed is what I use, so use the whole 3 cubic feet.

[@tomdifazio9895]

How many tomato plants can be planted in a 10 gallon grow bag

[@floridavegetablegardening]

You could put two tomatoes in one 10 gallon bag, but I prefer to just put one per bag so they aren’t so close together. If you put two in one bag then it would be a good idea to prune them some to encourage good air flow. If the leaves get too crowded together then fungus and disease can spread more easily. Also I would fertilize and water more frequently if there are two in one bag.

[@suer8463]

We plant 5 tomato plants in self watering containers that take 35-40 qts of "soil" per container. Would this mix be enough or do I need to double or triple the amounts?

[@floridavegetablegardening]

Hmm. So if my math is right, then you need about 45 - 50 gallons of “soil”. I think this mix would make close to that, but possibly a little less. I filled a 32 gallon trash can with it and there is more left over, but I’m not sure exactly how much more. I think it probably makes around 40 gallons worth. It’s probably close to what you need, but you might want to add some extra compost to stretch it a little further. Doubling it would be plenty more then enough, but then you would have extra if you wanted to use it for something else. I need to make more soon, hopefully this weekend, and I will try to get a better estimate of how much it makes.

[@floridavegetablegardening]

I just made another batch of potting mix and tried to measure the total amount I ended up with. My best estimate is that it comes to around 60-62 gallons. So one batch should be enough for your 5 containers.

[@suer8463]

Thank you!

[@floridavegetablegardening]

@@suer8463 You’re welcome!

[@jokerstyles6919]

What zone are you in? I’m in 9b

[@floridavegetablegardening]

I’m in 9b as well

[@SouthFloridaSunshine]

I am so grateful for the full day of rain we got down in 10b. The rainy season is coming, yay!

[@jokerstyles6919]

@@SouthFloridaSunshine yes it was nice to not need to water everything

[@jokerstyles6919]

@@floridavegetablegardening I’m on 5 acres. Trying to plant as much variety as possible. Planted a lot of citrus. Hopefully I don’t get the greening disease. I have a wooded area. I’ll try a orange and lemon in the woods also. We’ll see. I’ll be watching you for ideas 💡 thanks for sharing

[@floridavegetablegardening]

@@jokerstyles6919 that’s great that you have 5 acres. I hope to have that much land one day. I’m scared of getting citrus greening too, but I have read that when the citrus are planted among oak trees, they seem to be somewhat protected. We previously had lost some citrus to greening but now we have new citrus trees planted under our oak trees and hopefully it will help. It isn’t proven or guaranteed to work but so far they are doing good. I think we’ve had them for 1.5 or 2 years. It sounds like you’re on the right track with planting your citrus in the woods. Good luck! 😊

[@roywarriner8441]

I smoked two joints before I smoked two joints and then I smoked two more

[@floridavegetablegardening]

😄 They were my favorite band back in the day and still in my top three! 💚

[@mercedesbenzs600bash]

Why buy potting mix when your making your own potting mix???

[@althomas189]

Are you married? 😬