I've used coir for several years--it was Boca Bob that got me started using it. I grow almost exclusively in containers, mostly Earthboxes and Smartpots. I tried the coir by itself, but just didn't get great results. After some trial and error, I've settled on a mix of coir, Pro-Mix and some horticultural grade perlite. Makes a nice, loose container mix.

I also am very fussy about my coir. From now on, will only use the Coco-tek brand. Tried another brand one year, and it apparently was still way too saline. Even after flushing it many times, my plants would just not grow. As soon as I got rid of it (actually bagged it and put it in the trash), I went back to the Coco-tek and all was well.

Glad to see this discussion revived!

I haven't tried the coir, but I'm totally sold on winter sowing with vermiculite in a closed container anyway. I just found containers left untended in my shaded GH since June that still have living ( and perfect ) seedlings in them. Never would I have truly believed it if I hadn't seen it for myself. Absolutely amazing! I had no idea they'd hold for that amount of time.

Chelle, I saw an article you did about using the vermiculite. I am a bit nervous to try it this year because I know what has worked for me in the past and I'm kinda counting on germinating a whole lot of starts! But I think I will have to try it out soon.

Linda, thanks very much for that info about the coir brand. I'll have a look for that.

The one time I got a batch of coir that was "nice", it was GREAT. Then the next 3 batches were crummy, and I gave up.

Now I try to screen pine bark to be as much like the structure of coarse, fibrous coir as possible - but of course bark holds much less water. As a hopeless over-waterer, that's what I need.

It's easier to screen bark to be like very coarse Perlite - and much cheaper.

My raised beds appreciate my bark-screening fetish because they get the rejected powder and the big chips. The powder is an amendment I mix into the clay soil before adding it to the beds, and big bark chips are my preferred mulch.

Rick, it sounds like you've really worked out a near-perfect approach to your specific soil needs. That's impressive. No wonder your lavatera finally took off.

kylaluaz said:Chelle, I saw an article you did about using the vermiculite. I am a bit nervous to try it this year because I know what has worked for me in the past and I'm kinda counting on germinating a whole lot of starts! But I think I will have to try it out soon.

When you do try it, just set those containers in shade ...and forget about them. I fussed over mine way more than I needed to. Now that I know that the seedlings will hold for a very long time...my fussing, wondering and worrying days are over. If they're viable, they'll sprout...if they sprout, they'll keep. No more spring vacation anxiety for me.

Thanks, Kyla. It works for me, but then anything that kept me from drowning roots would be an improvement.

I'm not sure why I can't stop myself from over-watering seedlings. I feel as if I "should" water everything until water comes out the bottom. Of course, that is a good way to kill seedlings.

That one "good" batch of coir was even better for my clay soil than pine park. And it's benefit has lasted 3 years.

I have been using coir and perlite for years.. every container seedling and cuttings have it.. just love it still .. mine came from a farm here NJ that closed down.. coco tek was pretty good .. was trying to get you a link but my computer needs to be rebooted and running slow.. sorry

For a good selection of potting mixes and components like coir, perlite, vermiculite, shale, etc, try hydroponic stores. Their products might be a little more expensive but - well- you get what you pay for. Also try good local nurseries and ask to buy a bag of whatever they use for their own growing purposes.

Miracle Grow is the only potting mix my local Home Depot sells now. I used to buy ProMix there, but they haven't carried it for years now.

Karen

Chelle, I have done wintersowing in those translucent gallon jugs for years (I buy water in those,not milk, so no need to clean them) and I know how lovely it is! But with your vermiculite process, don't you have to make sure there is enough headroom by up-potting sooner? And, in the shade, eh? Interesting!

Anyway, I love checking on my babies in the spring: Oh! This sprouted! And that! Oh! But when it comes to it, who knows what I'll get up to.

Thanks, Allison, for thinking of me -- I found Cocotek online last night and was doing some comparison shopping. I think for right now I am going to go ahead and get some coir from Gardener's Supply. They advertise that they rinse it so the salinity is not an issue.

When I was looking into the offerings on Amazon, though, I was reminded about Azomite (a mineral amendment I've never used but heard great things about.) Anyone here have experience using it?

kylaluaz said:... But with your vermiculite process, don't you have to make sure there is enough headroom by up-potting sooner? ...

Well, that's a large part of why I was fussing and fretting, because I thought they'd get spindly and too tall while they were waiting on me, but no, the ones I just found in the GH stayed small. I'll try to get a picture or two today...so you can see, along with their sowing and sprouting dates (if I have those varieties noted).

Ah! I see. Well, how smart of the little sproutlets then, to wait so patiently for you.

I waited too late to get pictures today; there's now way too many peevish and nasty wasps out there! Maybe tomorrow morning...

Minnesota Home Depots still carry pro mix in bails.

That's encouraging, Rick! I have yet to call the local HD locations to check.

fingers crossed!

Our Menard's carries a Pro-Mix (just the very basic Pro-Mix) in a 4 ft. compressed bale for about 14.00. Toward the end of the season, it goes down to $10.00. I think it's a little too coarse for seed starting, but it's awesome for potting up seedling transplants, and I use it in my containers. The caveat is there is nothing that acts as a fertilizer in there, so that does need to be added. It is a good bargain for me, as I grow about 800 plants for our Master Gardeners plant sale each year. This is a fairly economical mix for potting up 3", 4" and 5" containers that have a little Osmocote mixed in. For seedlings, I just use a little water-soluble fertilizer and everything has done just fine.

mom2goldens said:Our Menard's carries a Pro-Mix (just the very basic Pro-Mix) in a 4 ft. compressed bale for about 14.00.

Wow, great deal! The only local price I can find right now is $38 for the 3.8 cubic foot compressed bale. I don't recall eve seeing a price lower than $27.

Maybe there is a lot of regional variation - the cost of shipping might be a big factor.

It's $50/ bale at a local hydroponics place.

https://www.wormsway.com/local...

Karen

Shipping costs can certainly influence the price of heavy items. Two years ago it was not unusual (with a little patience and looking) to purchase 2-3 cf. bags of orchid media such as Douglas fir bark and get free shipping. I ordered 3 bags of the stuff in June and shipping was almost $50! The same would be true for my coconut chunks, expanded rock, and horticultural charcoal. Nothing (in the amount I need) is available locally. I use approximately 20 cf. each year. I am being priced out of purchasing quality orchid-growing media. I will soon have to find a substitute bark. Perhaps the cypress I use in the landscape would work.

If I couldn't buy any of those things locally, I think I'd move Don't you have a city anywhere close?

Karen