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I was just reading the Greenhouse Grower article http://www.greenhousegrower.com/news/?storyid=2963. About a grower sending liquid dosers to his retailers to keep the plants looking good. He said he wanted the plants fed once a week. Which kinda suprised me. I am feeding every watering. Am I feeding too much? Our water has a pH of 8.4 and I don't want salts to build up if I am not feeding and adjusting the water pH. Let me know what you other growers are doing. I am fairly new at the game and can use a mentor so to speak. This forum is a great tool for info exchange...

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Shannon, I liquid feed at every watering and have been doing so at my nursery for over 25 years. How many PPM's (Part Per Million) one feeds and how often would depend on the crop being grow, time of year and soil type. I do "in house pour thru" soil soluble salts tests on my crops about every 10 days and also inject sulfuric acid with every feeding to keep the average soil pH of most of my crops between 5.8-6.2 except my Geraniums and Marigolds which I keep at a higher pH. I generally start crops at a 250 ppm nitrogen rate until about two weeks before they are going to be sold then start tapering off on the feed to tone the plants up a bit and make them tougher for life out in the real world. Once a plant is moderately mature and on the retail bench they do not require as much feed as you are no longer pushing growth but just trying to maintain a health salable plant. If anyone is real interested in learning all there is to know about liquid feeding plants, controlling water alkalinity and how to manipulate soil pH either up or down I recommend the booklet "Understanding pH Management For Container-Grown Crops" by William R. Argo & Paul R. Fisher. This booklet in my opinion is as good as a mini horticulture degree and a must have for any serious grower. It has saved me thousands and thousands of dollars in mistakes I would have made over the years on some crops.
Michael Pawelek
Pecan Hill Nursery
www.pecanhillnursery.com
PS- If anyone is interested in learning how to do the simple in house "pour thru" method for soluble salts readings in your crop I recommend the North Carolina Pour Thru Pages Web Site.
http://www.ces.ncsu.edu/depts/hort/floriculture/crop/crop_PTS.htm

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The Booklet published by Meister Publishing is actually on sale $15 cheaper than I paid for my original copy years ago!
http://www.meistermedia.com/store/mpro.html

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The pH of our water is 8.3 (Thank the Federal Drinking water Standards for that!) You must balance the pH or there will be trouble. We use Both concentrated Sulfuric Acid and Nitric Acid (not in combination but either one or the other. The Nitric acid is a little more expensive and you MUST be even more careful when handling it. The benifets to using Nitric Acid is that you do get some N value from it's use as well. If you are growing woody ornamentals We use a Harrel's Slow release fertilzer mixed into the soil at transplant time and subsequent years top dressing. We also use 150 ppm 21-7-7 Acid special on a once a week basis. If you are growing annuals, we still balance the water with acid but each annual's requirements are different so the type of fertilizer and the frequency of application will depend on the crop being grown.

Hope this helps.

Steve Mercer
Preston Greenhouse
Louisville, KY

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My water is from a well. We currently feed once a day and acid is mixed in with the fertilizer tank. We use Phosphoric Acic. I am interested to see if we are using the right feeds and such. Here is copy of our water analysis:
Soluble Salts mmhos/cm 0.437
pH 8.36
Alkalinity ppm 283.5
Calcium Ca ppm 15.61
Magnesium Mg ppm 3.781
Sodium Na ppm 86.97
Chloride Cl ppm 6.07
Boron B ppm .3443
Iron Fe ppm .0259
Manganese Mn ppm .0683
Sulfur S ppm 12.15
Copper Cu ppm .0076
Zinc Zn ppm .0003
Molybdenum Mo ppm .0040
Aluminum Al ppm .0234
Nitrate NO3-N ppm .037
Ammonium NH4-N ppm 0.0
Urea N ppm .51
Phosphorus P ppm 1.018
Potassium K ppm 9.949

We have two tanks one with Technigro 20-9-20 Plus and the other with Technigro 15-0-15 Plus. We were using Citric Acid to lower the pH. But found that we needed the Phosphoric Acid for blooming. We alternate feedings with two days in the 20-9-20 tank and one day in the 15-0-15. Is this the best approach? Could we be doing something better? What about trees and containers? Is there a slow release we could top dress with that would take care of pH and fertilizing? Lots of questions I know...any help is appreciated.

Steve said:
The pH of our water is 8.3 (Thank the Federal Drinking water Standards for that!) You must balance the pH or there will be trouble. We use Both concentrated Sulfuric Acid and Nitric Acid (not in combination but either one or the other. The Nitric acid is a little more expensive and you MUST be even more careful when handling it. The benifets to using Nitric Acid is that you do get some N value from it's use as well. If you are growing woody ornamentals We use a Harrel's Slow release fertilzer mixed into the soil at transplant time and subsequent years top dressing. We also use 150 ppm 21-7-7 Acid special on a once a week basis. If you are growing annuals, we still balance the water with acid but each annual's requirements are different so the type of fertilizer and the frequency of application will depend on the crop being grown.

Hope this helps.

Steve Mercer
Preston Greenhouse
Louisville, KY

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Shannon, Depending on your starting soil pH, where you want to keep the soil pH and how long it takes to grow the crop are some factors in how much you need to reduce the alkalinity of your water source. When I saw your water test results above I had to smile. You have crystal clear natural spring water compared to what I deal with here in S.E Texas! :) My alkalinity is in the 430's and my calcium content from the well water is around 140 ppm's so you won't find me using much 15-0-15 !!! I use acidic forming fertilizer formulations and try to keep my alkalinity under 100. Below is a link to a N.C. State web page that is a handy dandy calculator to determine how much acid it takes to get your water to a particular ppm or MEQ of alkalinity. You just plug in some facts on your water source and choose a type and strenght of acid and it tells you how many ounces to use per 100 gallons of water. The program will appear kind of strange at first but after some trial and error you will find it works quite well. By the way, with my alkalinity I cannot use phosphoric acid because I end up with way too much elemental P in my liquid feed mix. It's 93% sulfuric for me. Sulfuric is much cheaper to use also. I also blend my own soils and start at lower initial pH's than many growers knowing it's going to rise inevitably. Here is the calculator web page....
http://www.ces.ncsu.edu/depts/hort/floriculture/software/alk-calc/A...
Michael Pawelek
Pecan Hill Nursery
www.pecanhillnursery.com
PS- You can download the alkalinity program to your computer to use off line.

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Shannon what kind of trees are you growing?


Shannon Theall said:
My water is from a well. We currently feed once a day and acid is mixed in with the fertilizer tank. We use Phosphoric Acic. I am interested to see if we are using the right feeds and such. Here is copy of our water analysis:
Soluble Salts mmhos/cm 0.437
pH 8.36
Alkalinity ppm 283.5
Calcium Ca ppm 15.61
Magnesium Mg ppm 3.781
Sodium Na ppm 86.97
Chloride Cl ppm 6.07
Boron B ppm .3443
Iron Fe ppm .0259
Manganese Mn ppm .0683
Sulfur S ppm 12.15
Copper Cu ppm .0076
Zinc Zn ppm .0003
Molybdenum Mo ppm .0040
Aluminum Al ppm .0234
Nitrate NO3-N ppm .037
Ammonium NH4-N ppm 0.0
Urea N ppm .51
Phosphorus P ppm 1.018
Potassium K ppm 9.949

We have two tanks one with Technigro 20-9-20 Plus and the other with Technigro 15-0-15 Plus. We were using Citric Acid to lower the pH. But found that we needed the Phosphoric Acid for blooming. We alternate feedings with two days in the 20-9-20 tank and one day in the 15-0-15. Is this the best approach? Could we be doing something better? What about trees and containers? Is there a slow release we could top dress with that would take care of pH and fertilizing? Lots of questions I know...any help is appreciated.

Steve said:
The pH of our water is 8.3 (Thank the Federal Drinking water Standards for that!) You must balance the pH or there will be trouble. We use Both concentrated Sulfuric Acid and Nitric Acid (not in combination but either one or the other. The Nitric acid is a little more expensive and you MUST be even more careful when handling it. The benifets to using Nitric Acid is that you do get some N value from it's use as well. If you are growing woody ornamentals We use a Harrel's Slow release fertilzer mixed into the soil at transplant time and subsequent years top dressing. We also use 150 ppm 21-7-7 Acid special on a once a week basis. If you are growing annuals, we still balance the water with acid but each annual's requirements are different so the type of fertilizer and the frequency of application will depend on the crop being grown.

Hope this helps.

Steve Mercer
Preston Greenhouse
Louisville, KY

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