A lot of folks add fertilizer or compost to potting mix if the mix is lacking nutes. Some make container mixes. The amount of nutes to grow the greens is usually what the plant needs and hits the good nutrition levels for humans. So long as you have enough fertilizer/compost added to your mix to make the greens grow well, they will be plenty nutritous for eating.

Hi, Thanks for the quick response. Well, I am an organic gardener in pratice but I don't always know all the details. Sometimes I settle for understanding broadly the principle of how the crops interact with the soil and the biology of soil etc. And yes, I could add compost to the potting mix, but it would have to be biologically active, right? Not bagged and sterilized? And while I wouldn't use a general fertilizer, I could add organic fertilizers like green sand or blood meal etc., but it's been my understanding that adding those ingredients to potting soil, gives the fertilizers, nothing to work with, that there is no living system for it to interact with. No microbes or biological web.

Maybe I should have asked this question on the Organic forum,and Soil forum too, so I'm going to add that to this thread.

As for the idea that as long as there are enough nutrients in the soil for the greens to grow well than they will have the optimal nutrition, I'm wondering about that. I seem to have read somewhere that the fertility of the soil crops are grown in today is diminishing from what it once was. And therefore a lot of our food, even grown in the ground, have less mineral content. But they grow fine and look fine.

It's fine if you use organic chemicals instead of synthethic ones, there are organic potting soils, mixes, compost, and fertilizers out there now. Many people prefer organic over synthetic for their indoor and outdoor growing. If you wanted you could skip the solid medium and go hydro and just direct feed organic chemicals in a water solution. If you like, you can try your hand at microgreens, they pack a powerful nutrition punch. There's a lot of debate and prefrences with what to use or mix up.

And commercial Ag is a bit different than home growing a pot of something. Yes there is something to be said for soil depletion, but there are other factors in the ComAG industry that can be leading to nutritional changes in produce. Of note with greens is that they have been bred to be less bitter, and that has an impact on nutritional value. So not just the growing medium, but also other factors lead into changes in nutritional content.

But you aren't going all ComAG, just growing a few pots of greens over the winter. Don't need to overthink it. Just get a good organic potting soil, good seeds, and treat your plants well, and you will be fine.

PM2, as you alluded to in your previous comment, maintaining strict organic protocols when gardening in containers may produce less than satisfactory results. Organic ferts require a healthy and active soil biology to be converted to plant accessible forms and soil-less potting mixes just do not offer an environment conducive to these populations. Including garden soil or compost with the potting mix could help, although I'd caution against using soil as the particle size is too small and will lead to drainage and aeration issues. Compost is slightly better as it tends to be more textural and fluffy but should be used in moderation (a small percentage of the mix) and is a single season ingredient at best. You will want to discard the soil after harvest.

The second issue is that few if any organic ferts contain a full range of necessary plant nutrients so without access to a mineral-based garden soil or a compete synthetic fert, your plants will be nutritionally deprived......not just for your consumption but for their own health and vitality.

I have never seen any studies that evaluate the nutritional differences of crops involved with soil-less growing versus insoil plants but hydroponic farming is becoming a big deal.....at least on a small scale :-) Heck, there isn't even any scientific consensus that organically grown produce tastes better than conventionally grown crops or that they are nutritionally better for you. The jury is still very much out on that topic.

I have to admit that, in the past, I've had very poor luck doing what you propose. Now I live in middle CA so I can grow winter crops outdoors. But your question did make me think of other threads (perhaps on other Forums) about growing microgreens.

I use to grow microgreens when living in colder climates and these former threads got me back to growing them. Right now I have a dish of radish greens growing on my kitchen counter.

I'm a little lazy so I buy pre-made seed mats from Hamama.com and have had really good luck with those. Most people buy seeds and have their own systems for winter growing of various microgreens. I really enjoy having the fresh greens so handy.

GardenGal - Thank you for explaining what my understanding was that I was having trouble expressing. Normally, I'm only interested in growing houseplants indoors, or starting seedlings that will end up outside, so the nutritional value of the plants is irrelevant. But I have a use for Mustard Greens on a regular basis, for their spicyness and I'm having trouble finding them organic in the grocery store.

Right now I still have a row of them outside that I am using every day, but with a frost forecast for next week, that's not going to last much longer. So, I thought about getting set up to grow them in the house. I basically just need the spiciness and if it is a little low in mineral content, I can live with that. I'm not trying to set up an entire vegetable garden indoors to depend on for our diet. [g] I'm thinking I will pretty much get the spicy nature of the Mustard greens regardless of what I grow it in.

Still....yes, that was my understanding that, "...you need a healthy, active soil biology to convert...." I do find it fascinating to think about growing food indoors. Of course, people do it in greenhouses. I know Eliot Coleman does it with a hoop house attached to the back of his house and he does plant directly into the soil. But that's pretty complicated and limited and beyond the scope I could manage.

Beesneeds - Yes I agree about losing our ability to grow organically. A lot of the wisdom and experience of other generations was just not passed down to the next generations, when Big Agriculture became common. And I imagine being able to live and work a small farm became pretty difficult to sustain.

I'm not really a fan of Hydroponics.

Kate - Thanks, yes the last time I thought about doing this indoors, I did come to the conclusion that growing micro greens would suit my purposes at that point. Right now, I think I need the full Mustard leaves, for my purpose. But, yes, I’m going to have to try growing the micro greens too.

I used to be a fan of sprouts, but sometimes had the worry that I was going to do it wrong and introduce some bacteria or some other issue. Salmonella?

Is that a consideration with growing micro greens? When you grew micro greens, how did you use them? I normally add kale or spinach or mustard greens to smoothies, I wonder if micro greens would be just as good?

Also, isn’t it true that the nutrition in the micro greens is what is already provided by the seed, so that would eliminate the concern about whether the plants were getting enough nutrition from the growing medium?

Prairiemoon, if you go onto the Hamama website, lick on FAQ, and they will tell you all about the nutrient value, etc. of the various microgreens. You don't have to buy anything from them to read this.

I cut off a hunk of whatever I'm growing and toss it into whatever I'm going to eat.... cooked or raw. My DD grows them just to put in the breakfast smoothies. They all taste different. Right now I'm growing a mix of radishes that have added a bit of zip to whatever I'm eating.

I think one of the biggest advantages to microgreens is that you don't need a fancy setup or lighting arrangements, just a spot to on your counter/windowsill/whatever to sprout the seeds. You don't even need fancy equipment. I have a sprouting jar for sprouting wheat for my bread, a pan for cutting-greens and have even re-used a grocery lettuce box as a mini green house.

Thanks, I'm going to have to try that Kate, thanks for the link. 😀