Gardening and Horticulture - Holly Tree

I have a pretty holly tree tucked in a corner in my backyard----it's tilting all of a sudden looking for the sun---short of moving it---nowhere to move it and I don't want to risk it,---will it tilt back in the summer or spring--I just moved in this house and thought about cutting it down alittle and staking it.--It's very lovely looking and the birds perch on it behind my bedroom window.---but it is hearty and heavy and I better do something---my guy that landscapes suggested that-he said to wait till March to do it.