Ficus Fertilizing

[Aiden2020]

Hello all, I still haven’t figured out what is causing my ficus hedge to not be so dense and full of foliage.

There is a lot of empty spots as you can see in the photo attached.

Someone recommended I use fish fertilizer every other week.

Any recommendations how to get the tree to be more full?

Running drip line system in front and back of the trees - with holes a
Every 12” - every 3 days for 45 mins

 

[Oliver Buckle]

Ficus are not really outdoor plants in England, and I am not familiar with them as hedging. The way to get hedging plants to bush generally is to top them out, sometimes severely, but looking at the photo I wonder if the wall is to blame? Look at the amount of growth above and below the top of the wall. I know it is painted white, but plants can be very sensitive to shading.