Tree leaching nutrients from front garden

We have a silver birch in the corner of the front garden, and I am sure it is leaching significant amounts of water and nutrients from a about a 3m radius. I never really bothered before, it was mostly grass that was affected, and I plant alpines around the tree because they can stand poor conditions quite well. Now however the tree seems to be getting to the hedge down the side of the house, and a hydrangea we have. They are all a pretty poor shade of lime green, leaning towards yellow tbh.
I need advise on what I can use to put nutrients back into the soil. Now maybe isn't the best time of year for feeding plants but they look pretty sorry for themselves. I am thinking maybe some bfb?

The tree will take water and nutrients from an area at least as wide as the leaf canopy.
It's getting toward leaf shedding time anyway for the hydrangea, so I wouldn't add any fertiliser now as the plants go to sleep for the winter. Feed in the spring with BF&B or any slow release fertiliser and water well

MoS, I've found recent research that most trees actually forage water and food from closer to twice the height of the tree. At one time it was believed that they foraged the width of their canopy, but that's been found inaccurate.

I have 100 year old maples along my west property line and the tree canopies end at the west edge of my house. However, during various digs at the east side of the house, we've found huge tree roots circling the house! They've actually wound around sidewalk and garage footings heading toward my east neighbour's house.

Trees and veg gardens really don't mix unless the veg are in raised beds where tree roots can't get access.