In our area, we have alkaline soils. They are soils over a pH of 7 (under this would be acid soils you find in the Eastern parts of the US). An alkaline soil contains a high degree of calcium, sodium, iron, and magnesium. This makes the soil limit the available nutrients. Plants that like a more neutral soil or even acid soil end up with leaves turning yellow in the summer, especially in dry soil. The plant will become stunted and more prone to winter damage.
Luckily, they are many trees and shrubs that are tolerant of alkaline soils. The problem comes in growing acid “wanting” trees and shrubs even if they are tolerant of the winter cold. Some of the shrubs that you find in greenhouses for sales like azaleas, rhododendrons, witch hazels, kalmias, and holly will not thrive. I have tried holly but after 4 years of not growing finally gave in and died.
You noticed with hydrangeas with the beautiful blue flower fade to pink after a year or two. If the soil is acid, the flower is blue, if alkaline the flower is pink or an ugly pinkish white.
Some of the trees that want acid soil and are even cold tolerant of our area are most oaks, red maples (many are also borderline cold tolerant), and magnolias. To a lesser extent many pines, birches, and silver maples.
To fix alkaline soil is a bother, adding sulfur (3 oz sulfur to one square yard of soil). If the soil is clay or sand, mixing in peat moss helps bring it to a neutral pH. There are home test pH meters that are accurate and cheap, so you know what your soil pH is.