Tomatoville® Gardening Forums - View Single Post

Sojourner · June 20, 2015

I've been searching desperately for a new mix. For 50 years I was a Cornell Peat-Lite adherent, or some variation thereof. I eventually settled on 1:1 peat/coarse vermiculite - but then the availability of coarse vermiculite dried up. I haven't been able to get it for over 20 years now in any of the areas I've lived in in that time. Trying to order it from a greenhouse always - ALWAYS - has ended up with me getting MEDIUM grade or finer, while the greenhouse folks try to insist it is coarse.

I didn't fall off the turnip truck yesterday. Although I did have another greenhouse again try to convince me that medium grade is coarse grade literally just yesterday, LOL!

Now Home Despot and Lowe's both have stopped carrying coarse grade perlite (unless you are willing to order a whole pallet) and the large 4+ cu ft bags of peat moss. The 3 cu ft bags they are carrying now cost about twice what the 4+ cu ft bags do. I've had to turn to hydroponics stores for potential potting medium ingredients - which, while still more expensive than the Big Box stores, has the advantage of being about half what the local nursery wanted to charge me for coarse grade perlite - and the hydroponics store stuff is higher quality for that price. I think it was $60 for 4.5 cu feet of Thermorock from the nursery and $30 for 4 cu ft of Mother Earth? from the hydroponics store. Might have been 4 cu ft vs 3.5 cu ft.

I'd love to give pumice a try - but despite being mined in this state, I have had no luck at all finding horticultural grade pumice locally. The only stuff I can find is Dry Stall, which is shipped in to some local feed stores from CA.

I have tried "gritty mix" and a modified "gritty mix" and both were utter failures - the modified "gritty mix" actually failed later than the conventional. The modified had 16% peat and growstone in it in addition to the usual gritty components. I suspect the peat contributed more to the staving off of disaster than the Growstone, but who knows. I'm not growing bonsai, cacti, or succulents. It didn't work for me.

I am in the process of transplanting all of those plants out and back into a peat-based boughten mix. Seedlings planted in peat-based boughten mix are doing just fine, btw.

After discussing the "gritty" type mixes with an actual soil scientist, it is clear to me why those failed - and its not because I am stupid, lazy, hate my plants, and/or incompetent. Its because those types of mixes require special handling that I am simply not able - or willing, for that matter - to provide. If gritty works for you, more power to you. It doesn't work for me, and if I don't lose all those seedlings due to giving it way more than a fair shot to outperform garden variety peat mix, I'll be VERY lucky. Honestly I should have done that as soon as the experiment started to fail.

For now I'm pretty much stuck with continuing to experiment to find something I can mix up myself, that doesn't cost the earth, and for which I can EASILY find the components. I have used a dry-stall/bark/peat mix that was ok - but I found it too dense, probably from fines in the bark. My next attempt will be a 1:3 Growstone/peat blend vs a 1:1 peat/coarse perlite blend. I'll see how annuals planted in those do before making any other changes.

Its just that I hate perlite sooooo much.

As for the gross aspersions being cast in certain quarters against peat moss based mixes, calling them "pudding" and "soup" - all I can say is, for 50 years, everything I've planted in a peat-based mix seems to think soup is good food!

June 20, 2015	#17
Sojourner Tomatovillian™ Join Date: Nov 2014 Location: Earth Posts: 27	I've been searching desperately for a new mix. For 50 years I was a Cornell Peat-Lite adherent, or some variation thereof. I eventually settled on 1:1 peat/coarse vermiculite - but then the availability of coarse vermiculite dried up. I haven't been able to get it for over 20 years now in any of the areas I've lived in in that time. Trying to order it from a greenhouse always - ALWAYS - has ended up with me getting MEDIUM grade or finer, while the greenhouse folks try to insist it is coarse. I didn't fall off the turnip truck yesterday. Although I did have another greenhouse again try to convince me that medium grade is coarse grade literally just yesterday, LOL! Now Home Despot and Lowe's both have stopped carrying coarse grade perlite (unless you are willing to order a whole pallet) and the large 4+ cu ft bags of peat moss. The 3 cu ft bags they are carrying now cost about twice what the 4+ cu ft bags do. I've had to turn to hydroponics stores for potential potting medium ingredients - which, while still more expensive than the Big Box stores, has the advantage of being about half what the local nursery wanted to charge me for coarse grade perlite - and the hydroponics store stuff is higher quality for that price. I think it was $60 for 4.5 cu feet of Thermorock from the nursery and $30 for 4 cu ft of Mother Earth? from the hydroponics store. Might have been 4 cu ft vs 3.5 cu ft. I'd love to give pumice a try - but despite being mined in this state, I have had no luck at all finding horticultural grade pumice locally. The only stuff I can find is Dry Stall, which is shipped in to some local feed stores from CA. I have tried "gritty mix" and a modified "gritty mix" and both were utter failures - the modified "gritty mix" actually failed later than the conventional. The modified had 16% peat and growstone in it in addition to the usual gritty components. I suspect the peat contributed more to the staving off of disaster than the Growstone, but who knows. I'm not growing bonsai, cacti, or succulents. It didn't work for me. I am in the process of transplanting all of those plants out and back into a peat-based boughten mix. Seedlings planted in peat-based boughten mix are doing just fine, btw. After discussing the "gritty" type mixes with an actual soil scientist, it is clear to me why those failed - and its not because I am stupid, lazy, hate my plants, and/or incompetent. Its because those types of mixes require special handling that I am simply not able - or willing, for that matter - to provide. If gritty works for you, more power to you. It doesn't work for me, and if I don't lose all those seedlings due to giving it way more than a fair shot to outperform garden variety peat mix, I'll be VERY lucky. Honestly I should have done that as soon as the experiment started to fail. For now I'm pretty much stuck with continuing to experiment to find something I can mix up myself, that doesn't cost the earth, and for which I can EASILY find the components. I have used a dry-stall/bark/peat mix that was ok - but I found it too dense, probably from fines in the bark. My next attempt will be a 1:3 Growstone/peat blend vs a 1:1 peat/coarse perlite blend. I'll see how annuals planted in those do before making any other changes. Its just that I hate perlite sooooo much. As for the gross aspersions being cast in certain quarters against peat moss based mixes, calling them "pudding" and "soup" - all I can say is, for 50 years, everything I've planted in a peat-based mix seems to think soup is good food!