Fertlizing Hippeastrum And Other Amaryllids

Josh Young joshy46013@yahoo.com
Sat, 11 Jun 2011 07:42:37 PDT

   Thank you so much for the clarification, it's very difficult to find a fertilizer that uses Nitrates for Nitrogen with the correct overall analysis but I am one step closer :)  


From: J.E. Shields <jshields@indy.net>
To: Pacific Bulb Society <pbs@lists.ibiblio.org>
Sent: Friday, June 10, 2011 7:29 PM
Subject: Re: [pbs] Fertlizing Hippeastrum And Other Amaryllids


You have the most important things right:

Nitrogen mainly as nitrate.  Ammonia (or urea) encourages bacteria and 
fungi to grow.

Potassium (K) balances nitrogen (N) approximately.  Bulbs use large amounts 
of both nitrogen and potassium.  The phosphate (P) is not so important.  I 
recommend an N-P-K ratio of 20-10-20, but 20-5-20 would probably work just 
as well.  Bulbs use much less phosphate.

Feed with every watering -- continuous liquid feeding is recommended.  Use 
N at about 100 ppm.  Don't over-feed.  The idea is to supply the nutrients 
as fast as the plants take them up.  Too much salt in the medium is hard on 
the roots.

Use a water-soluble inorganic fertilizer.  Organic fertilizers, just like 
ammonia and urea, encourage the growth of potentially pathogenic bacteria 
and fungi.

I got my first lessons in how to feed Hippeastrum from Len Doran, 35 or 40 
years ago.  Reference books I recommend to give you more of the science 
behind this:

A. R. Rees, "The Growth of Bulbs" Academic Press, 1972.

A. de Hertogh and M. Le Nard, "The Physiology of Flower Bulbs" Elsevier, 1993.

Jim Shields

At 03:43 PM 6/10/2011 -0700, you wrote:
>Hi Guys!
>    I'm wondering what you guys use to fertilize your Hippeastrum and 
> other Amaryllids?  I use a fertilizer that's nitrogen is primarily 
> sourced from Nitrate Nitrogen  and a small percentage from Ammoniacal 
> Nitrogen, does anyone have any suggestions?  I think the breakdown is 7-8-6.
>    My Hippeastrum seem to really like it, I feed at 1/4 strength with 
> every watering.
>Anderson, IN

Jim Shields             USDA Zone 5
P.O. Box 92              WWW:    http://www.shieldsgardens.com/
Westfield, Indiana 46074, USA
Tel. ++1-317-867-3344

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