From

Location

Message

Date Posted

Santa Rosa, CA.

Is a 6.8 PH ok in a soil high in om or should I be trying to get it to 7?

2/16/2013 9:59:54 AM

Menomonie, WI (mail@gr8pumpkin.net)

PH fluctuate I would leave it there

2/16/2013 10:03:11 AM

Rapid City, SD

grew PB in ph of 7.4 here

2/16/2013 11:15:45 AM

Spanaway

steve deletas was at 7.3 last year

2/16/2013 12:52:10 PM

Santa Rosa, CA.

Matt-man what is your om like. Mine is high and I have read that a lower ph is better in high om soils. I wonder what Don Young's ph was when he grew his 1600's. Hopefully he will read this and reply.

2/16/2013 1:35:18 PM

spring 2007 om 24.4 ph 7.4
fall 2007 om 22.4 ph 7.1 grew 1662

spring 2009 om 35.6 ph 7.6
i did add sulpher to lower grew 1658, 1622
fall 2009 ph 6.3

2/16/2013 2:15:20 PM

Santa Rosa, CA.

Thanks Don. That was fast! So does anyone have experience using oyster shell flour to up the ph and Ca. How much would you use on 750 sf?

2/16/2013 2:31:33 PM

Germany

Oyster shell powder is CaCO3, just take Bry Langleys soil calculator and add a fertilizer with about 40% calcium, then enter your patch size and your initial calcium concentration...and now vary the amount of your 40% calcium stuff (which represents your oyster shell powder) until you reach your target Ca level.
You can´t predict the final pH, because pH depends on so many variables in your soil. The fortunate thing about oyster shell powder (and other CaCO3 powders) is that you won´t get too much above pH 7. (6.8 is very nice already, I started with pH 5.4-5.5 in 2011, had pH 5.8 in 2012 and grew 900lb-ish each year)

2/16/2013 2:45:56 PM

Germany

http://greatpumpkincommonwealth.com/index.php/resources

There you can find the soil amendment calculator (Langley Soil Estimator).

2/16/2013 2:47:42 PM

Petaluma,CA

I used oyster shell powder last year to bring my ph from 6.2 up to 7. Used 5 lbs per 100 sf.

2/16/2013 2:53:40 PM

Western PA

Organic matter will generally drop your ph through out the summer, so you may want to get it close to the mid 7's.

Don's is a perfect example.

2/18/2013 11:32:55 PM