Nhu, Let's say "excessive nitrogen" rather than high nitrogen. Plants normally take up only the amounts of nutrients that they need. The excess phosphate in high phosphate fertilizers is going to be ignored by the plant. Feeding a plant on a high phosphate fertilizer may simply amount to starving the plant for nitrogen and/or potassium. Excess potassium in high potassium fertilizers may interfere with uptake of calcium (?) but is not itself going to flood the plant with potassium. Nitrogen may be the exception. It can stimulate growth. If not balanced by potassium, that growth can go mainly to foliage production. Building the bulb up or forming a new inflorescence would require plenty of potassium. Without the K+ to balance the nitrogen, you may not get balanced growth in the whole plant. Why don't you run this past some professional plant physiologists at Berkeley and report back what they tell you? I'm just a simple biochemist, and I only took one course in plant biochemistry -- albeit at Berkeley, but that was still over 50 years ago. Jim Shields At 08:35 AM 6/11/2011 -0700, you wrote: >Jim, > >I read somewhere that high nitrogen fertilizer causes the bulbs to produce >lots of leaves in expense of the bulbs. Is this true? Have you experienced >this with other slower growing amaryllids like South African winter growing >ones? > >Nhu ************************************************* Jim Shields USDA Zone 5 P.O. Box 92 WWW: http://www.shieldsgardens.com/ Westfield, Indiana 46074, USA Tel. ++1-317-867-3344