7/19/2009


Hi Everyone..

Yesterday I was at my local nursery and I was
told that Citrus love high nitrogen, I was told to use
30-10-10 , I usually use 20-20-20 , what is your opinion ?



Cheers...Joe...

Between the two choices you list, for containerized citrus, in my opinion, 30-10-10 is by far the best. - Millet (1,279-)

Is the prduct you are talking about Miracle Gro's Miracid? I saw that the other day when I was looking for a good water soluable fert and almost bought it until I realized that the the nitrogen source was very high in urea (27 or 30% I think?). I only say this because I know of a few members on this site that have used this product with success but I am still leary because of the high urea content. I guess what I am getting at is that it is just about IMPOSSIBLE to find a good water soluable fert to compliment my slow release. Any suggestions?

The absolute VERY BEST fertilizer for containerized citrus trees, is manufactured by the J.R. Peters Company, under their Jack's trade mark. The formula is 25-5-15 W/trace minerals, which provides the perfect 5-1-3 ratio, which is the ratio of nutrient uptake absorption by citrus roots. Absolutely none of the nitrogen is derived from Urea. It is sold in 25-lb. bags, which I purchase from their distributor in Denver, Colorado. J.R. Peters has distributors throughout the United States. They are the #1 supplier of fertilizer to the U.S. greenhouse and nursery industry. An amazing fertilizer for container citrus.- Millet (1,277)

Thanks Millet. I have heard you talk about this product before but I have been hesitant to make the 25 pound purchase. I was hoping to find something sold in a smaller quantity, but after visiting no less than 5 local nurserys and doing research online I think I might just have to man up and make the purchase.

Joe

I don't see that ratio formulation listed anywhere on the jack's website.

http://www.jacksprofessional.com/prod_overview.html

Do you have any other recommendations, something a little bit easier to locate? Or a combination of two that can be mixed to the desired ratio?

Brian, you are correct, it is not yet listed on Peter's web site, which I find a bit odd. Peter's 25-5-15 fertilizer is a relatively new product for the Peters Company. I think it has been out for perhaps 7-10 months. I see it being advertised in the magazine "Greenhouse Grower" and other publications of the greenhouse and nursery industry. I purchase it 50-lbs. at a time and have been using it since it first became available.. You can telephone the Peters Company and ask for the location of their closest distributor in your area. Be sure to ask, if that distributor carries this particular formulation, as Peters Company manufactures many different formulations of fertilizer. If all fails let me know and I will help members out that wish to use this fertilizer. - Millet (1,277-)

I have had horrible luck with Miracid and other Miracle Grow fertilizers. My citrus did very poorly while using this product and demonstrated signs of what I believe is biuret toxicity. Keeping everything else the same, I then switched to Dyna-Gro foliage pro 9-3-6 plus minors and the trees now look great.

-Brett

What another option to acidify soil other than Miracid?

Since I am cynical and don't believe anything I read, I am curious what the experts have to say about whether Miracid actually acidifies soil as stated. Does it acidify because of its sulfur content? If so, I am under the impression that sulfur takes quite a long time to acidify soil after it is added. If someone applies Miracid once a month or so, doesn't the sulfur content just get leached out of the soil during the other waterings. Perhaps this phenomenon is different with in ground plants compared to pots. Maybe I am way off base, educate me.

-Brett

It has nothing to do with sulfur, or at least very little. Ammonium based fertilizers lower medium-pH (acidifies) through the action of nitrifying bacteria, that naturally occur in the medium, and also especially by plant roots that take up the ammoniacal nitrogen. In both cases, bacteria or plants release acidic protons (H+) into the media resulting in a lower pH. In urea fertilizers, urea is converted into ammonium before being taken up by plant roots, and therefore also acidic. The percentage of ammoniacal nitrogen in a fertilizer equals the (percentage of ammonium + percentage urea)/percentage of total nitrogen. In general, the higher the percentage of ammoniacal nitrogen in the fertilizer, the more acidic the reaction will be, and the faster the medium-pH will decrease (become acidic). For example, 21-7-7 and 9-45-15 (both 100% ammoniacal nitrogen) are more acidic than 20-20-20 (70% ammoniacal nitrogen), which is more acidic that 20-10-20 (40% ammoniacal nitrogen). - Millet (1,276-)

Thanks for the clarification Millet.

-Brett

Millet, not sure I 100% agree. The ammonium vs nitrate effects are quite correct for the nitrogen component alone. But the miracid formulation has other dominating ingredients, namely ammonium sulphate, ammonium phosphate,and magnesium sulphate as sources of N, P, S, and Mg.
It also seems to contain potassium chloride as the K source, which adds extra chloride for no advantage.
According to K.Handreck, Growing Media for Ornamental Plants and Turf
" the higher the proportion of the total N that is present as ammonium and urea, the greater will be the ability of the fertilizer to lower mix pH.
Per unit of N, ammonium sulphate and monoammomium phosphate have about double the acidifying ability of urea and ammonium nitrate.
Diammonium phosphate is halfway between these two groups."

Further to the actual fertilizer ingredients, is the pH of the irrigation water
being used
" With waters of very low total alkalinity, it may be necessary to use a nitrate-N to ammonium-N ratio of about 8:1.
A more common ratio for pH stability is 2 or 4:1
The effects of alkaline water supplies can be countered by having more ammonium and urea than nitrate.
If further acidification is needed in areas where the water is highly alkaline, the water used must be acidified with concentrated acids "

So do the acidifying fertilizers work ? In theory they should, but it will be further complicated by the pH of anyones local water source.
If you had low pH water, and using acidifying fertilizer, you would be further lowering the pH when you make up the liquid fertilizer. If you had high pH water, you may only drop the pH of the liquid fert. by a little bit, and not significantly acidify anything.
Also you should consider the strength of the liquid fert. you make up when you actually measure your powder(grams) into your water(litres).This will determine how acidifying it is, along with the frequency of application.
It is very important to be accurate, but also consider that the label mixing rates are very general and should be treated with caution with valuable container plants. All liquid ferts you make or buy are 'saline', in that you can measure the EC (electro conductivity) of the final liquid you apply to your plants. The stronger you make your mix, the higher the final EC will be !
It may be wise to use a low strength mix at first as a test run. Then use low strength more frequently, rather than full strength monthly etc (especially for young seedlings) .Also when making liquid fertilizer, check and make sure that ALL the powder is dissolving. If your water is high in certain elements, it may stop one of the chemicals in your fertilizer dissolving correctly
(Note that any dry fertilizer is also 'saline', some also being slow release
and gradually add nutrients (salinity) to the container)

pagnr, everything you say, is certainly true, and will effect the pH of a medium. In the discussion between Brett and myself, we were only discussing how an acid type of fertilizer lowers the pH of the medium. However, your correct that in the full context, other common additives such as the the choice of the medium, irrigation water, components including peat, bark, coir, vermiculite, limestone and other possible buffers, all play a roll, and can affect the pH. Thanks for the additional information.- Millet (1,276-)

I use 30-10-10 and my citruses are fine.

It's nearly impossible to fine 5-1-3 fertilizer anywhere. I would love some though.

Lowes, Home Depot, OSH, et al. definitely don't carry 5-1-3 ratio. Mostly all their brands are in the 3-1-2 ratio, which is pretty general.

I remember FourWindGrowers recommend 3-1-1 fertilizer for their trees. It say so on all their tags.

Cheers,