the dilemma of peat moss - seed starting alternatives?

I have searched and searched the internet for possible alternatives to peat moss in regards to indoor seed starting mixes, cannot find a thing. I really don't want to use this natural resource, what are my alternatives for starting seeds indoors successfully? I have not read good things about the coconut alternative when it comes to keeping the seedlings indoors very long into growth.

We use potting soil and starter mix.  You can make soil blocks using your existing garden soil.

Are you trying to avoid peat moss all together? I do what Anne does and have been using a potting soil to start my seeds in, and if memory serves me correct, it does contain some peat moss. This year I'm going to do a little experiment, and take a shovel full of soil from one of my raised beds, which I've spent years building and nurturing, and try that for seed starting next to a tray of the potting mix I have been using, as a control, and see what my results are. One difference I can say right now is potting soil mixes are often steam sterilized, so there's generally no disease or bad bug eggs or bad nematodes in it.

I would like to avoid peat moss completely as it is not a renewable resource. Wondering if sterilized soil really makes a difference? What about loss of beneficial microbes and fungi during the sterilization process? Anyone ever tried starting seeds indoors using just regular organic potting soil?

My mother used to grow tomato seedlings in a clay flower pot full of soil from the veggy garden. She also, later, had a hot frame where she grew a large variety of heirloom tomato seedlings. I did this for her a couple of times so have a good idea what was done. I dug out the hot frame down about 2 feet and put in about a foot of well composted hot manure. Then I back filled the topsoil on top. She just scattered the varieties of seed in on top and thru some luck or magical knowledge always managed to get all the varieties to produce tomatoes. She grew a lot of the seedlings that were handed out to a community garden in Pittsburgh. All out of that in a 2 foot by 4 foot, or so, hot frame.

She had a pink tomato that I'd name after her as the momsname Perfect Pink beefsteak. It was a regular leaf pink beefsteak. The stem went into the tomato and never left a single crack or mark of any kind. The bottom was also perfect. The skin wrapped around the sides and just continued. It was a very meaty tomato with small seed cavities. I think she got it from her mom and the tomato may have been in the family since the early 20th century. We lost it the summer before she passed. Every tomato in the garden came up a cherry tomato. Have no idea what happened.

You could worry about picking up a disease or whatever out of the seedling soil, or you could just say well they grew up with an immunity to what they'd just see a couple months later.

I grow plants in mostly coconut coir for an entire growing season. I typically add a bit of peat, and a bit of weed free compost.

The problem I have with planting into pots of soil, is that my soil is filled with all manner of weed seeds. Lots of weed seeds.

Organic potting soil often contains peat.

Joseph Lofthouse said:


"The problem I have with planting into pots of soil, is that my soil is filled with all manner of weed seeds"

I usually grow my seedlings in 12 oz foam coffee cups, doubled to keep the top cup from water logging. However last year I used a couple 1020 trays as I needed more seedlings for a project. But then I transplanted what I needed in my own garden into the cups. In the cups I put my usual stones then a small layer of peat moss, a layer of mushroom manure and topped it with more peat moss. The mushroom manure was steamed a couple times while used to grow mushrooms. And then I aged it. I found that this made the plants healthier but still, as usual, leggy. I transplant into the garden and put the tomatoes as deep as a foot, so the leggyness isn't a problem, at least in my own mind.

I bring this up because you could substitute garden top soil for the mushroom manure. My bottom peat layer served as a filter and the top layer served as a sensibility buffer. If you're using garden top soil then the top peat layer is a weed mulch. When I plant my tomatoes a foot deep that kind of blocks the weed growth, but remember you got those weed seeds out of the garden where they returned. I came up with this idea because I've come to the conclusion that the seeding mixtures don't have enough nutrition and I've never used a chemical fertilizer.

Remember what the intent here is to reduce the use of peat moss.

Aida Alene wrote:I would like to avoid peat moss completely as it is not a renewable resource. Wondering if sterilized soil really makes a difference? What about loss of beneficial microbes and fungi during the sterilization process? Anyone ever tried starting seeds indoors using just regular organic potting soil?

Here's the thing, seedlings do not need fertilizer of any sort or amount, using it can lead to stem rot, stem bolt (fall over death knoll).

Expanded mica (vermiculite) and or pearlite are the best mediums (other than sand) for starting seeds without using any peat products. Peat, by the way is an acidifier all on its own.

Once the seedling has that second set of true leaves open then you can add just a little all purpose fertilizer and I mean like 1g per 2L solution.

Redhawk

Spent coffee grounds are quite inert in the beginning. Although they have nutrient value, it takes some time for the woody texture to break down. No weed seed could survive being roasted, ground up and having hot water poured on it. It doesn't bind really well, so perhaps something could be done about that, but it is otherwise a suitable medium.

I don't just want to reduce the use of peat but rather eliminate it, I'm also worried about the sustainability of vermiculite. It bothers me to think about using resources shipped from far away that had to use energy to make or extract. Perhaps I'll try just using soil and see how the seeds do this year

Dale Hodgins wrote:Spent coffee grounds are quite inert in the beginning. Although they have nutrient value, it takes some time for the woody texture to break down. No weed seed could survive being roasted, ground up and having hot water poured on it. It doesn't bind really well, so perhaps something could be done about that, but it is otherwise a suitable medium.

I was considering coffee grounds as a medium in potting soil but wasn't sure the acidity effect on the seeds?

If peat, vermiculite, perlite, and coconut coir are off-limits, due to concern about fuel used to manufacture and/or transport them, or due to concern about mining/disrupting Earth's resources, then perhaps there are local resources that could be used and collected in a wheelbarrow or wagon. Some combination of soil, compost, and/or sand might work well. If I put damp soil in a closed container in the greenhouse, for a couple weeks during the hottest part of the summer, that more or less kills the weed seeds. The container can be something like a bucket or plastic bag. It helps to plan ahead to kill the weed seeds so that I can use the soil for starting plants the following spring.  I can also minimize some types of weeds by putting soil in shallow containers, and keeping it watered and sometimes stirred for a few months before it's needed.

A good natural seed starting medium is earthworm castings. Best source to secure larger amounts would be to find a local fishing bait company that breeds worms. A 30 to 50% mix with fine sand will prevent clumping.

Aida Alene wrote:I don't just want to reduce the use of peat but rather eliminate it, I'm also worried about the sustainability of vermiculite. It bothers me to think about using resources shipped from far away that had to use energy to make or extract. Perhaps I'll try just using soil and see how the seeds do this year

Then you are limiting yourself to using only compost, composted manure, leaf mold, worm castings, bird droppings litter(composted) and river sand, gravel, forest soil. The last three are detrimental to the environment so I would suppose you will leave those out.
That means you are going to have to plant your seeds directly into the soil for the most part.
It also means you are going to miss out on many beneficial substances that are available.

Redhawk

I have great success with expanding Grow-It brand coco coir blocks. I do rinse after expansion until my ppm is below 50. I then mix with 30% perlite. I also top dress with worm castings after the 2nd true set of leaves.

RedHawk, usual sharp sand? That is an idea and cheap. I strike all my cuttings in pure sand and use the sand many times (insofar it is eco). Did it really work for you?
I used to use usual potting mix I buy at the landscaper per trailerload and sieve it. There's some pine bark in it sand and I think cow manure.
I tried to do the hotframe once and it dis not heat up.

Lorne Martin wrote:A good natural seed starting medium is earthworm castings. Best source to secure larger amounts would be to find a local fishing bait company that breeds worms. A 30 to 50% mix with fine sand will prevent clumping.

Crikey, that is so much easier to find than compost red wigglers. Are they the same worm? I search "red wiggler bait" and it looks like it. I'd love to buy a pound of those cats and wheedle some castings out of the deal. Sure they don't like being shipped; then I can confine shipping to black soldierfly larvae (though in my NYC compost bin they self-colonized).

A pound of compost worms in the cities is expensive and worse, inconvenient. Plus, country bait worms have fewer neuroses and don't get bored as easily.

Geoff Lawton's potting soil mix is simply 50% sifted compost, 50% river sand.  He's got a river that runs past his property, and they go down to an outside curve and dip it right off the bottom with a bucket.

My addition to that mix is simply to add as much biochar to the mix as I've got available.  My potting mix is probably 10% biochar.

Just that easy.

I've got an fine-mess screen sifter that I use to top-off the pots with compost, so that the top quarter inch or so is a fine almost powdered compost material on which to plant the seed, and then I sift a bit more over the pot to cover the seed.

I really don't even like using peat moss -- it's too rough and clumpy.

At the end of summer, I do a massive garden clean up and get a hot compost pile going with a couple of 5-gal. pails of coffee grounds.  By the time the compost is finished, it's a fine material that is full of nutrients and lots of beneficial microorganisms.  Why would you ever sterilize your garden soil?  My germination rate is fantastic and the plants quickly grow in the fertile mix.  And best of all, I don't spend a penny buying perlite or other soil ingredients.  I get my sand at the beach, my compost from my garden, and the biochar form my fire-pit.

Angelika Maier wrote:RedHawk, usual sharp sand? That is an idea and cheap. I strike all my cuttings in pure sand and use the sand many times (insofar it is eco). Did it really work for you?
I used to use usual potting mix I buy at the landscaper per trailerload and sieve it. There's some pine bark in it sand and I think cow manure.
I tried to do the hotframe once and it dis not heat up.

Yes I use river sand and bottom heat for seed starting and it works quite well as long you keep them misted so there is no drying out.
I also use pure vermiculite for a few "stubborn" seed varieties since that medium will hold more water while also letting air in.
I should also mention that I do add microorganisms to both mediums, both bacteria and mycorrhizae.

Redhawk

I use a timer for the misting.

Lately when I make up some potting soil I use coir.  I like it although I don't like the distance it travels to reach me.  
I'm determined to start a worm farm this spring just for potting soil use.

I was trying to find if the gravely shale bits in the creek in our back yard might be useful in a potting soil and learned that 'expanded shale' called haydite is used for this.  When I checked how to do it I see it's not a do it at home project.
In the search though I found this list of potting soil materials and a bit about each one.  The list is aimed at bonsai growers but many are commonly used in potting soil mixes.  I think I'll try the shale bits as they are and see what happens...
http://www.colinlewisbonsai.com/Reading/soils2.html

I've had pretty good success using compost.  We do some composting, but I'm too lazy to keep up the maintenance on the pile, so the results are inconsistent.

However, the nearby town as a composting program that produces excellent compost from mostly yard waste (they accept yard waste for free and sell the compost).  It only costs $15 a yard and they typically give you more than a yard.
They are a certified facility (I forget which composting organization) complete with temperature monitoring, etc.  so the compost is excellent quality, with all the seeds, etc. killed by the hot temps they maintain.

It's sifted compost, (unsifted is only $12), I think they use a 1/4" screen as the larger particles are around 1/4".  The mix of particle sizes provides good drainage with good moisture retention.
For container plants I usually mix in some perlite and wood chips, but for starting seeds, etc. I typically just use it straight.

hau Judith, you might try sieving the shale bits so you are dealing with fairly consistent size pieces.

I have used shale once or twice but I have a steel mortar and pestle that I used to grind down some of the chunks I had at the time into smaller bits.

Redhawk

In my situation have lots of blow sand, sheep and duck manure. There are 3 constants where am right now.
The blow sand builds up in the barn and have to clean it out on a regular basis, so am wondering if it might be
of any use starting seeds. Any suggestions?

Will be moving soon, so it will be plants for the new place.

I've used good garden soil that I sterilized on the charcoal grill. First attempt was in the oven. Bad idea, unless you want your entire house to smell like roasted dirt. The same soil, wrapped tightly on foil and cooked on a covered grill will kill any fungus, weed seeds, or bugs. Good aged compost usually doesn't need to be sterilized.

This could also be a good use of a solar oven

Aida, I understand the need to not use peat moss.  When we decided not to use it in our composting toilet for all the reasons you listed, we found we had something called 'stump dirt' in our woods.  It is decomposing logs and stumps almost to the point of becoming soil.  We break it up and sift it and use it directly in our toilet.  We mix it with sand from our creek and some wood ashes saved from our fires to make seed starting mix.   The toilet "end product"😊 is ready to be composted and the seed starter worked really well last season.  If you have white ash trees where you live, we found that when the heart starts to rot out, you can use the outside for firewood, the inside for stump dirt and there are usually an abundance of big white grubs as well for the chickens. Good luck on your quest to find things closer to home and less damaging to the environment.

I have always considered peat moss off limits for my gardening needs, too.  The industry is just so devastating to wetlands and to the planet in general.  Natural Life Magazine has a good article about the subject.  The Washington Post reports that they're trying to phase out its use completely in Britain:

"In Britain, for example, using peat has become taboo. The government’s environmental agency has said it wanted to phase out peat moss for hobby gardeners by 2020 and commercially by 2030. The London-based Royal Horticultural Society, the largest gardening organization of its kind in the world, has reduced peat use by 97 percent at its four major gardens and urges its members to follow its lead."

The Post recommends substituting compost, coir, shredded pine bark, Pittmoss (a commercial substitute), rice hulls or worm castings.  

One commenter at that article recommended just using well aged compost:

"I have had compost piles at the back of the garage for decades. The turning is almost beyond me now, so I do the minimum and just wait longer. I find it far superior to peat, and there are no pH problems. My yard beds have been fed with it for years, and a garden designer told me once that I had 'great dirt!'. It works well in pots and doesn't dessicate and shrink like peat does. And it's free."

I went looking for more advice and found this idea too:

"Believe it or not...when I was young, I had a neighbor who grew his African Violets in an interesting mix....crushed eggshells, shredded newspaper, and coffee grounds...LOL He grew the nicest violets I have ever seen.:) But he always was one to "swim agains't the stream""

The University of Florida's extension office has a good page listing all kinds of ingredients and recipes to use.  One of theirs is:

Soil-Based Mix

This mix is heavier than peat-based mixes, but it has good drainage. Vermiculite or perlite can be used for sand.

   1/3 compost; 1/3 topsoil; 1/3 sand

I don't start a lot of seeds indoors, so it's never been a big issue for me.  My go-to mix for when I do is rather nontraditional and probably won't work for a lot of people.  We live next to our local high school and they have a greenhouse where they grow and sell garden plants every spring.  The greenhouse is only open for the month of May and after the season they let the employees take home any plants they want and they just toss the rest.  My husband gets permission to take flats of them home.  Some years I am able to rescue a lot of plants.  We planted 40 extra tomato plants last year from some rescued flats.  Even if they're dead, though, I have him pick up the flats and I reuse the trays and the soil mixes for filling new raised beds (combined with soil, compost, dried leaves, etc.) and for starting my own seeds the next year.  I figure they contain materials I wouldn't buy like peat and chemical fertilizers but I'm okay using them when I'm keeping them out of the landfill and they're free resources for my gardens.  

Good luck!

I have a feeling all types of moss have probably adapted to absorb water, because they don't have roots.  If i have to scrape moss off the north roof every year, it sure seems like a renewable resource to me, lol.  (curmudgeonly gentleman farmer).  Anyway maybe any moss is a possible substitute for peat moss.  

Shredded bark (true bark mulch) is reportedly high in nutrients.  Now I just need a way to shred it.  If you hear the lawnmower making a racket that's just me making potting soil.  

I figure the "stump dirt" may be similar to partially-composted woodchips; and probably great for soil but maybe better after adding nitrogen.  

-Mike

I'm using 2/3 leaf mold (passed through a sieve) and 1/3 sand.

Takes a little planning ahead of time (so it will be available), but there are things you can do to help speed the process along.

...renewable resource, hardly any expense

The original reason for using peat as a seed starter was that commercial growers didn't want to sell off the topsoil they had, or that they were an industrial organization and didn't have topsoil. If you're unwilling to use peat then just use the topsoil from your garden and when you set out your seedlings put the entire contents of your container back in the garden where it came from. The evidence that topsoil will work is the millions of years of history the seeds have with growing in dirt. If there were problems with this method then the hot frame would have never become an accepted way to grow seedlings. Just try it. Put a few tomato seeds in a coffee cup of topsoil and set in on a window sill. They will grow, trust me.

I used to think that one needed a sterile potting mix to start plants.  My dad, with his commercial chrysanthemum nursery, believed that because he rooted all his cuttings in peat moss and perlite mix.  He also imported trucks of peat moss from Canada as an amendment for his grow beds which he tilled and used commercial fertilizers and pesticides.  In between crops he would tarp it with heavy chains along the sides of the bed and run steam from his huge oil burning boiler to steam sterilize the beds. Yes, as a 17 y.o. I read "Silent Spring" and from that day on I would fume and argue with my parents on their planet abuse.

I was hanging out looking for a seed starting mix at the local hydroponics store.  Yep the one that sells fertilizers with a marijuana leaf on it but haven't partaked of it since college.  They turned me on to Happy Frog potting mix as a seed starter and it's chock full of microbial wealth.  I put the regular cell pack tray with the dome on a seedling heat mat with a block of styrofoam underneath on top of wire shelving in a sunny south window.  Put the soil in the cells, plant, water the tray, not from the top, and got pretty much 100% germination.  Once germinated, I took the dome off and continued to heat, watering the tray, never from the top.  Once true leaves appeared, I pricked the seedlings out and replant into home-made newspaper pots with Happy Frog potting soil and placed them back on the shelves in a disposable aluminum roasting pan, again, watering the tray and not from the top.  I didn't loose any transplants unless I was stupid about hardening them off, which did happen. The seedlings grew fast and lush.

I am now so sold on Happy Frog that it's the only stuff I regularly buy.  I tend not to buy soils because I live in a pretty fertile valley.  I do some container gardening because of a gophers and voles.  I will use it for my grow bags which I kinda pseudo hugelkultur with a bunch of trimmings at the bottom of the bags.  I then fill it with Happy Frog so that it's not weedy on top.  Everything I plant in this mixture is growing really well and I haven't really had to fertilize it that much for the first year.  It's made of "aged forest products" so it's kind a hugel on it's own.  It does have perlite in it, and I am emotionally opposed to using perlite in a regular garden bed because the little white fluffs annoy me, but for seed starting and container growing it can't be beat.  No I don't work for them or get paid by them.  Just a totally happy customer.

Meanwhile, the gophers and voles are digging up some good loose soil for me to fill my raised beds with!  Turns a problem into a solution.  Just need some good gopher cages for my trees and hardware clothed raised bed bottoms.  The dog keeps on chasing the stray cats off the property....

Several references to rotting wood and the large white grubs. I read somewhere that this was the first potting soil. The rotten wood has excellent moisture holding and the frass [excrement] from the grubs has a good bacteria profile and it is usually weed free. When I am collecting the rotted wood and I find the grubs I put them in a bucket with partially rotted wood and let them complete their life cycle. I have 2 buckets ready for this season and sand subsoil from an excavation.
I also have some anaerobic pond bottom gathered after the pond dried. Someone tried to use it as a stating medium but it was full of seed of a niche plant that uses that space so crowded out the seeds planted. It is a fine mix of clay and anaerobic compost with a gel like quality. I think I will solarize it as Lofthouse recommended and try it again.

So the take away from this thread is: As a permaculturist Observe carefully the materials you have and prepare and combine them for the consistency you want in a seed starting medium.

Suggestion to try.  gather pond moss and save it for the next year.  I mulch trees with it and love it there for moisture holding.

our heavy clay soil is horrible here so i make my soil w/ coco coir ,fine river sand and worm castings. coir is a renewable resource. i have 2 good sized totes w/ probably 500 worms in each one. i change out their bedding w/ fresh coir every 6mo. i get probably 80lbs of castings each time. besides scraps, i feed them comfrey leaves and they really grow well and produce quality castings for us. all my coffee grinds go in there too with a little lime to balance ph. worm castings are black gold to a gardener! 3-4 yr old sawdust turns into a nice dark soil once broken down. i start all my compost heaps with a thick layer of sawdust then add my scraps. the sawdust acts like a sponge holding moisture in. i add urine to it also to help it beak down faster.

I've actually put 4in pcv pipe with small holes in it in my compost heap to help get air in there to aid decomposition. it helped some but not worth the effort. perlite, coarse gravel , coir however does help get more o2 to the roots aiding growth. fabric pots are also amazing to aid in growth.

Hi
I have followed this discussion of the use (or non use rather!) of peat moss for seeds starting.
What about seeds stratification? What can be a substitute for peat moss for stratifing seeds successfully?
Cheers