Fertilize Canary Island Date Palm

[palmie 1]

I have a mature Canary Island Date Palm that needs fertilizer badly.  The margins of the fronds are turning yellow prematurely. I finally got the right fertilizer, but I’m not sure how to apply it.  The instruction says to apply it to the area under the canopy.  But the area under canopy are mostly hedges and grass. What do I suppose to do? 

Apply the fertilizer to the hedges and grass and hope that the wrong fertilizer won’t kill them and some will make it to the root zones of the palm??  

Alternatively, skip the hedges and the grass, apply only to the Root Initiation Zone (RIZ) of the palm wherever possible, including the dormant aerial roots?

I’m in South California.  The fertilizer I initially ordered was Palmgain, but it never arrived.  I went to a local store and got Palmtone (organic 4-1-5) and Epsom Salt instead to mimic Palmgain.  Since Palmtone is organic, I'm assuming it's ok to apply close to the trunk where the RIZ is.

Any help would be greatly appreciated!

Edited June 11 by palmie
formatting error

[8B palms 112]

Hi Gwen,

Most palm fertilizers are fine to use on your lawn and shrubs no problem, however, lawn fertilizer is not conversely good for palms, I think you can simply apply in the shrubs and lawn, maybe others might have more knowledge

[palmie 1]

Thanks Craig!  I do notice that the Milorganite lawn fertilizer is affecting my Magnolia tree adversely causing it to develop oversized but thin leaves.  It's either the nitrogen rich Milorganite or the seaweed foliage spray I've been using on that tree, I doubt that it's the latter.