I forgot what you said about screening the pine bark fines. I tried sifting through the 1/2 inch and then through the 1/4 inch and came up with this on top of the 1/4inch.(pic below)
Aren't those too big?
Tapla: Questions about your gritty mix
That's pretty big, but it will work if the other two ingredients are the right size. I usually use prescreened fir bark in 1/8 - 1/4".
At the top:
Al
Al, if you think it would make a difference I am going to buy this:
http://www.hardwareandtools.com/Jackson-Wire-11061615-1-8-By-36-By-10-Redi-Roll-Hardware-Cloth-6100804.html
Btw, where do you get pre-screened pine bark fines? You've probably answered this and I've forgotten.
You can buy 1/8" hardware cloth at almost any good hardware.
I buy a product packaged by Shasta Forest Products, Yreka CA at an orchid dealer (Oak Hill Gardens) in Dundee, NW of Chicago.
http://www.oakhillgardens.com/htm/supplies_growingmedia.htm
Al
Do you buy the fine grade or which? 30.00 might not be out of the question for a 3 cu. ft. bag.
I usually get 20 bags of the fine bark at a time & pay $15 ea. I pick it up myself whenever I'm in the CHI area.
Al
Wow! You must do an awful lot of potting. I went ahead and ordered the 1/8 inch screen and will try doing it myself first.
I have more than 250 plants in the gritty mix & most get repotted every other year - some every year, and I don't reuse the soil. Plus, I usually get my arm twisted and have to share with friends, so I allow for that, too. You know how that goes. ;o) I used to buy Turface by the pallet (40 bags), too. Fortunately, I now have a local wholesale source so I can buy in more reasonable quantities.
Al
Al,
Do you use the 5:1:1 mix at all anymore, or have you switched to all gritty?
Oh yes - I use the 5:1:1 mix for everything short term. .... use it for veggies & all the display containers for the gardens. I only use the gritty mix for anything that might be in the same soil for more than 1 growth cycle (year).
Al, what do you do with the used soil?
I'm not Al, I'm just not that cool, but I dump my used soil on top of the leaves that I compost in my vegetable bed every year. If I have extra, I use it over the mulch on perennials where I'm pushing zone hardiness.
I have clay soil, so this mix should improve it. Til Al converted me, I used Promix and it never caused any problems, aside from a few volunteer flowers in the veggie garden.
I dump used 5:1:1 mix directly on the gardens or beds, or add it to the compost pile. Used gritty mix goes into the nursery beds where I grow material on for bonsai.
Al
I use my used mix on outside plants that need a little topdressing but mulching would smother them. The potting mix is easy to sprinkle on.
Thanks.
I have question(s) regarding the soil pH of both the 5-1-1 (without lime at this point) and gritty (with gypsum) mixes. I scooped up some of each into pots, watered them and used my combo water/light/pH meter to check them. Both of them are very high pH. Any thoughts, comments, suggestions? The water in my area is "hard" but for watering container plants, I "age" my tap water for at least 24 hours (not sure what effect this has but have always done it). Anyway, my chemically-challenged mind needs some help.
The prelimed pH of the 5:1:1 mix will be somewhere between 4.0 - 4.5. The pH of the gritty mix w/o lime will be about a point higher.
You are reading the pH of your water, primarily. To get media pH:
* Soak soil in containers to container capacity with distilled water.
* Wait 30 minutes to 2 hours for equilibration of nutrients in container solution.
* Place containers to be tested in a shallow saucer to collect leachate.
* Pour 1/2 cup of distilled water over the surface of a 1 gallon container.
* Make sure your equipment is properly calibrated (had to add that).
* Test pH of leachate
Aging your tapwater probably has no effect on anything. Fluoride is not volatile, nor are the newer compounds of chlorine used for chlorination. So as water evaporates during the aging period, it actually concentrates the dissolved solids.
Al
Al, thanks for the info. My testing efforts were with a multi-use meter (light, moisture, pH), just a probe. Anyway, I did the leachate test with the probe and the results were highly alkaline. Thinking the probe at fault, I went in search of another means of testing and found only a small kit of test tubes and powder capsules (wasted money, I think). I tried both the water and soil in separate tube tests and got basically nothing. Problem: me, equipment, soil, other -- what? If all else fails, guess I'll try to county extension service. Mary
Mary - my considered advice is just forget about the pH of your media. It's really not that important. The pH of the soil solution in container culture is much more important than media pH, and there is really nothing a hobby grower without access to a variety of fertilizer chemicals and sophisticated testing and mixing equipment can do to maintain pH. A number of factors affect pH in container media - the components of the soil, fertility levels, moisture content, temperature, plant material, more .... even time of day has an affect on the pH of container soil (solution).
If you tell me why you're concerned about pH, and what you're trying to accomplish, maybe I can help you with suggestions that will allow you to skirt the need to monitor pH. You'll drive yourself crazzzy trying. ;o)
Al
"The pH of the soil solution in container culture is much more important than media pH" -- I don't unnerstand this statement... Anyway, I'd just like to know I'm potting plants in a soil they'll benefit from. I know you've said it's possible to grow plants in marbles, etc., but in doing that would there be the question of whether the growing "soil" was acidic or alkaline? I intend to plant herbs, veggies, etc. in the 5-1-1 and mainly cacti/succulents in the gritty mix. :) mg
First, to ease your mind, there are thousands of people using both the gritty mix and the 5:1:1 mix and reporting great results. I've been using the soils and studying the related sciences for a long time, and I honestly have never seen better mediums for containerized plants. You can read bias into that if you wish, but I'm pretty honest and objective, so if I knew of a better soil, I'd not only be telling you about it ..... I'd be using it, too. I was at GW for several years before I joined here, so those folks have a head start. ;o)
To explain the statement: in short, container media have a higher CEC than mineral soils on a bulk density to bulk density (weight to weight) ratio, but because the bulk density of container media is usually only a fraction of that of mineral soils, the CEC and buffering capacity ends up being much lower on a per volume basis. Since the buffering capacity of container media is so low, container media pH has much less affect on the pH of the soil solution and nutrient availability than does mineral soil pH. Zzzzzzzz?. ;o)
You've seen pictures of some of the plants/plantings I grow? I NEVER worry about media pH beyond using some common sense in whether I choose dolomitic lime (raises pH) or gypsum (doesn't raise or lower pH) as a Ca source. If I see an indication that the pH is getting too high, I simply acidify my irrigation water with vinegar or citric acid.
It's normally not the pH of your medium that causes issues, it's the pH and alkalinity of your irrigation water you need to be most concerned about.
Al