Anyone care to share their homemade potting mix recipe? - Page 3

Gardeneer · May 3, 2015

Quote:

Originally Posted by drew51

Well that article sums up why I use compost and always will.

Israeli researchers discovered that vegetable and herb seedlings raised in a mix of 40% vermiculite, 30% peat moss, and 30% composted cow manure grew faster, with less incidence of disease, than those raised in a 40% vermiculite/60% peat moss mix (5). To understand how compost suppresses disease, it is helpful to know how plant substances are broken down during the composting process.

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That blend seems to be highly moisture retentive to me.
Maybe it works in Israel's dry climate with controlled watering, in a research operation. But it you use it, for example, in our PNW with annual rainfall of about 60 inches a year, you will have a soggy container. Peat moss itself holds too much moisture then you add vermiculite which absorbs a lot more water and swells like tiny balloon.

drew51 · May 3, 2015

Well if you're worried about water retention I would suggest replacing the peat moss with compost. Both are about the same, well no, no other compost holds as much water as peat moss, which is a compost btw. So you would not gain any more holding ability, actually lose some by this method. the value of compost is too great to ignore. Here in the Midwest we get between 31 and 42 inches a year depending on what state you're in, so adding peat and compost is not really a problem MN has less rainfall than TX! My state (MI) is 40 something. I find it rather dry to tell the truth. I have watered everything everyday the last three days, and it's only early May. We have some rain coming in this week, so I'll let it dry out good now.
I just finished my planting out today. The weather is at last good enough to plant out! A little ahead of schedule, but the coming weeks look warm enough. Night temps in the 50's.

hiker_ · May 6, 2015

Concentrate the watering near the stem...at least I was doing *something* right!

But I think where I live is just too humid for such a water-retaining mix.

Quote:

Originally Posted by drew51

Here in the Midwest we get between 31 and 42 inches a year depending on what state you're in, so adding peat and compost is not really a problem MN has less rainfall than TX!

I used to live in WI...it was much dryer there than here in RI. In winter the same temp here feels a lot colder because it's a "raw" cold. I can imagine needing a lot more water retention there!

Found this: http://www.currentresults.com/Weathe...cipitation.php

Don't know how accurate it is but it says:

MI 33"
WI 33"
WA 38"
RI 48"

So, here's the new mix I'm going to try in hopes that it's less water-retaining than the old one:

about one and two thirds 5-gal buckets of sphagnum peat
about 1/4 of a 5-gal bucket of perlite
about 2 quarts vermiculite
about 6 Tbsp lime

I'll also try one that has the same proportions as above except no vermiculite. It'll be an interesting experiment.

drew51 · May 6, 2015

Keep experimenting till you get it right. I know I have been adjusting mine every year. One day i will figure out the best for my area. I'm at the other end, my soils are too dry, I keep thinking of ways to retain more moisture in it.
It rained all day yesterday. I was worried my pots would be way wet, but they are already looking dry. Not dry enough to water, but drier than i would like after 20 hours of rain.

May 3, 2015	#32
drew51 Tomatovillian™ Join Date: Dec 2013 Location: Sterling Heights, MI Zone 6a/5b Posts: 1,302	Well if you're worried about water retention I would suggest replacing the peat moss with compost. Both are about the same, well no, no other compost holds as much water as peat moss, which is a compost btw. So you would not gain any more holding ability, actually lose some by this method. the value of compost is too great to ignore. Here in the Midwest we get between 31 and 42 inches a year depending on what state you're in, so adding peat and compost is not really a problem MN has less rainfall than TX! My state (MI) is 40 something. I find it rather dry to tell the truth. I have watered everything everyday the last three days, and it's only early May. We have some rain coming in this week, so I'll let it dry out good now. I just finished my planting out today. The weather is at last good enough to plant out! A little ahead of schedule, but the coming weeks look warm enough. Night temps in the 50's. Last edited by drew51; May 3, 2015 at 11:38 AM.

May 6, 2015	#34
drew51 Tomatovillian™ Join Date: Dec 2013 Location: Sterling Heights, MI Zone 6a/5b Posts: 1,302	Keep experimenting till you get it right. I know I have been adjusting mine every year. One day i will figure out the best for my area. I'm at the other end, my soils are too dry, I keep thinking of ways to retain more moisture in it. It rained all day yesterday. I was worried my pots would be way wet, but they are already looking dry. Not dry enough to water, but drier than i would like after 20 hours of rain.