Author Topic: fertilizing containerized trees  (Read 2193 times)

brian

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fertilizing containerized trees
« on: May 22, 2014, 02:14:33 PM »
I've increased the number of trees I have in containers and now I am getting sick of mixing buckets of water-soluble fertilizer to fertilize them all.  Is it possible to use time-release Osmocote as the sole fertilizer, foliar spraying only, or Osmocote plus a foliar spray?  Foliar spraying is far easier to do on a large scale than mixing buckets for me because of the tiny amount required.  And I can mix osmocote into the potting mix or add it on top later.

I have Jack's Professional 25-5-15 - thanks to whoever posted that coupon code on the CGF.  Is this usable as a foliar spray?  The instructions don't mention this.  It contains 0.12% iron, and I know iron is not recommended for foliar spraying.

I also have Osmocote Plus (with micronutrients) 15-9-12, which doesn't have the right NPK ratio for citrus.  I would have to add extra and deal with too much potassium and phosphorous.  How big a deal is this?  I repot yearly, and when outside all trees get rained on regularly.  When i water manually I usually give around a gallon to each tree.

Millet

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Re: fertilizing containerized trees
« Reply #1 on: May 22, 2014, 07:44:46 PM »
Just because 25-5-15 is the perfect formula as it is a 5-1-3 ratio, that certainly does not mean the other formulas are bad.  Osmocote Plus (with micronutrients) 15-9-12 would work well as a slow release fertilizer. Using a fertilizer as a foliar spray is normally used at 10% of the application rate shown on the bag.  I make up 55-gallons of fertilizer solution in a plastic drum at a time so that I don't have to make many small solution of fertilizer for each tree. - Millet

brian

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Re: fertilizing containerized trees
« Reply #2 on: May 23, 2014, 01:42:42 PM »
Thanks, Millet. 

So is it safe to use Jack's HPF as a foliar fertilizer on citrus, at the low concentration?   

I need to get a 55gal rain barrel anyway, my 5gal buckets are not sufficient anymore.  I was corcerned that leaving fertilizer mixed with water might cause it to degrade too quickly but it sounds like that is not the case. 

I am thinking I will use osmocote during spring repotting hwn trees get rained on outdoors, and move to rain-barrel water with liquid fert in the greenhouse in the winter, as I have very hard water.

Millet

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Re: fertilizing containerized trees
« Reply #3 on: May 23, 2014, 03:19:56 PM »
brian, when you make 55-gallon of a fertilizer solution, just e sure to keep the drum's lid on the drum when not in use. - Millet