All the sources I've seen so far are fairly adamant that potting soil is for containers, dirt is for the ground, and never the two should switch places or mix together. I hardly ever read instructions on bags of dirt and other material, but for some reason I read the verbiage on a bag of potting soil, which says you CAN mix dirt and PS together. So now I'm confused.

Different plants require diff mixes. Whether it is inground or containerized. Soil mixing absolutely!

As you can see on the instruction, the sub heading says 'In-ground planting', so it is quite clear in that aspect, mixing it in with the native soil in the garden, for planting into the ground directly.

Now for container gardening use, the potting soil itself and you can further add pumice or perlite to help keep it well aerated, roots able to breathe below soil level.

Yes, that is an instruction for installing plants in the ground. Mixing potting soil with native soil helps the newly installed plant find its way from potting soil (where it grew up) to native soil (where it will end up). Rather than forcing the plant to make a hard transition, the mix you use to refill the hole gives it a sort of bridge to its endpoint.

I do nothing but container gardening. If your plant is going in a pot use potting soil only. There are additives you can use like perlite, etc., but I've never found them necessary. I do use a starter fertilizer for cuttings and seeds. Fertilizer every six months or once a year depending on the plant. The good potting soil or potting mix will have lots of stuff in it, but no dirt from the actual ground - not ever. Actual ground soil will just clog up the works.

I make a potting soil blend each year from peat, perlite, vermiculite and compost. A trashcan full each year. I seem to use it up each year. But that is for containers and seed cells.

Baja_Costero said:Yes, that is an instruction for installing plants in the ground. Mixing potting soil with native soil helps the newly installed plant find its way from potting soil (where it grew up) to native soil (where it will end up). Rather than forcing the plant to make a hard transition, the mix you use to refill the hole gives it a sort of bridge to its endpoint.

Best explanation. Now I understand. FWIW, I'm doing mostly container gardening because the soil on our property is poor. Some spots I have revitalized with amendments, but containers are easier for me because the plants thrive in them. Well, mostly.

Brinybay said:

Best explanation. Now I understand. FWIW, I'm doing mostly container gardening because the soil on our property is poor. Some spots I have revitalized with amendments, but containers are easier for me because the plants thrive in them. Well, mostly.

Let me put it another way. Potting soil is essentially sterile and you add some dilute fertilizer after the seeds have sprouted inside in it. Soil is microbial active with stuff that can harm a small seed but is beneficial to a growing plant.

Does that help any?

Yardenman said:

Let me put it another way. Potting soil is essentially sterile and you add some dilute fertilizer after the seeds have sprouted inside in it. Soil is microbial active with stuff that can harm a small seed but is beneficial to a growing plant.

Does that help any?

Yes, thank you!

Yardenman said: I make a potting soil blend each year from peat, perlite, vermiculite and compost. A trashcan full each year. I seem to use it up each year. But that is for containers and seed cells.

I know this is an older thread, but I'm glad I found your post. I'm doing container gardening and looking for recipes for homemade mix - but there are so many different ones out there. Gets confusing.

I found a recipe like yours and was surprised to see it used no potting soil or mix. Does this mix work well for tomatoes and peppers? Does it hurt to add a little potting soil yo that mix?

It is a recipe for making potting soil in instead of buying bagged potting soil.

Of course you can add bagged potting soil to what you're making; then I would ask why do you want to make your own? Cost? To create a custom mix specific to your plants and conditions?

Some companies have formulated excellent products so you don't have to buy a lot of separate ingredients and figure it out yourself. If you are entirely inexperienced, I'd recommend buying good bagged potting soil at first. Then spend time studying the qualities of all the possible ingredients and learn why or why not you might add them to a homemade blend before trying to make it yourself. Gardeners have devised innumerable recipes and use a variety of ingredients for their own potting needs. It's largely an experimental process to discover what works for you.

For me, it's about cost. I need a lot for containers this year, and need to keep costs down. I'm going to amend what I have from last year. My gutters were so bad, that all the organic matter in them composted, so when they were cleaned, I saved all that stuff to use. I can't really compost here because of all the hungry wildlife.

Okay, now I understand your question. We've had the debate about reusing potting soil several times in various threads and there are different opinions (from Always to Never) and different recipes and approaches. Yes it is confusing. Ask five gardeners and you'll get six answers!

I can only speak for myself. I reuse & refurbish mine—I have too many large pots to be constantly replacing it. Minus roots and not if the plant appeared diseased. I don't have a regular recipe. This year so far I've mixed in some new rich bagged soil, compost and slow release fertilizer. I'll adjust that depending on what I'm potting. Might add some coco coir for more water retention or perlite for more drainage.

There are YouTube videos about how to renew used soil. Some I've seen were so complicated it didn't seem worth the expense and hassle. I'd suggest finding one that seems workable for you. As long as your gutter compost is thoroughly decomposed it would be a good addition.

NMoasis said: Okay, now I understand your question. We've had the debate about reusing potting soil several times in various threads and there are different opinions (from Always to Never) and different recipes and approaches. Yes it is confusing. Ask five gardeners and you'll get six answers!

I can only speak for myself. I reuse & refurbish mine—I have too many large pots to be constantly replacing it. Minus roots and not if the plant appeared diseased. I don't have a regular recipe. This year so far I've mixed in some new rich bagged soil, compost and slow release fertilizer. I'll adjust that depending on what I'm potting. Might add some coco coir for more water retention or perlite for more drainage.

There are YouTube videos about how to renew used soil. Some I've seen were so complicated it didn't seem worth the expense and hassle. I'd suggest finding one that seems workable for you. As long as your gutter compost is thoroughly decomposed it would be a good addition.

No debate here. I've always used and reused potting soil and things grow and flourish just fine. I'd be somewhat embarrassed to share how many years I've used the same soil. Yes, some of those YouTube videos are unnecessarily complicated. I watch and then just do my own thing.

This year, I need lots more than usual. I bought coir, perlite, vermiculite, some peat moss, and a big bag of Miracle-gro garden soil. Almost all the veggie seedlings I started indoors are doing so well, i need to fill a lot of containers. Plus more for the rock garden stuff I hope to attempt. So the more I can bulk out what I have, the better. I may still need to buy one big bag of potting soil. I bought some at the dollar store, and it's actually pretty good stuff.

I have bags of garden soil, perlite, & poultry grit. I want to mix them to use in some containers outside & for some houseplants I need to repot. I have read different measurements but am leaning on 2 parts soil & 2 parts a mix of grit & perlite. (1) Does this seem right for a general purpose mix? (2) Anything else I should add?

Kathy547 said: I have bags of garden soil, perlite, & poultry grit. I want to mix them to use in some containers outside & for some houseplants I need to repot. I have read different measurements but am leaning on 2 parts soil & 2 parts a mix of grit & perlite. (1) Does this seem right for a general purpose mix? (2) Anything else I should add?

That appears to be a pretty heavy mix, I would also add some coir and some perlite to lighten it up.

Thank you for the explaining the confusion. Now I understand the meaning of potting soil. And also about fertilizers. I plant roses in containers, because I have more rose plants than I have space in my yards. One of companies that I purchase the plants does not want me to use fertilizers in the potting soil, because the fertilizer would burn the young potted roots of the self-root roses that I like to purchase---after lots of my roses morphed to Dr. Huey roses. After so many years I still do not know much about container gardening----especially about holes in the containers. I have used self-watering pots--misunderstanding and not watering it has killed an expensive kaffir lime leave plant---HOW many HOLES does a container need? How big should the holes be? On the bottom or on the side? Since I pot lots of pots on my wood deck, I understand now to put the pot on some stand, better with wheels so the water can drip from the pot to the deck and still enable the water stream away----and easy to move the containers. Some people put rocks inside the pots, some people say do NOT put anything beside potting soil in the pot. All very confusing to me, I am now retired so I have more time at home that I can spend on gardening. And do you use fertilizer in the water when you water the plants? LOTS of questions---

I guess, I could use a bigger container without holes, put rocks in the bottom and then put the pot with the plant on top of the stones. But make sure that the water is not above the stones after watering the pot with the plant?

Horticultural definitions and what you should be buying for the ground versus pots;
*Dirt - Something you wash off of your hands.
*Soil - Comes from the ground, it can have various ingredients like sand, clay, silt, etc... Use for planting trees, shrubs, & grass.
*Potting Soil - Has soil in it. Usually is too heavy for pots alone, but good for planting in the ground.
*Potting Mix, Soilless Potting Mix, & Grow Mix - Are all made for pots with a variety of non-soil ingredients, like peat, coir, perlite, compost, ground bark, worm castings, etc... This is what you are looking for when growing in containers.

Excellent post Cullen.

Should you still want to use backyard soil - To determine the rough percentages of components of your native soil you can always put about a pint in a quart glass jar, fill the jar with water, cover and shake well. Let the materials settle and you will have a rough idea of what your soil is made up of and what you would need to add.

Thank you Cullen, so I need Potting MIX, but without fertilizers--so now I still need to find out about the holes in the containers, and with or without rocks---At least 1 hole at the bottom, and put either something to prevent the soil to stream out the pot. Someone told me, it is find to elevate the pot with empty closed strong bottles underneath the pots to elevate the pots on decks---