As soon as late frost becomes a thing of the past, it’s time to plant hydrangeas. To produce a long period of blossoming in hydrangeas, it’s essential to choose the right location. Hydrangeas like to anchor their roots deep in the soil, so make sure their bed isn’t resting on top of cement, stone, or any other unpenetrable material. Other decisive factors for location are sun intensity and air flow. Hydrangea is happiest in a half-shady spot sheltered from wind. Although most kinds will tolerate strong sun or full shade, you’d have to adjust your watering schedule accordingly: in full sun, water more frequently, for shady spots less.
Before moving the plant from pot or other container into an in-ground bed, give it a soaking for 10-minutes. Also, dig a hole for your hydrangea that’s twice as wide as its current container. Then, place the plant into the hole and pat the earth down around it. Hydrangeas appreciate a good watering as they settle into their new home. Both bigleaf mountain hydrangea need soil that’s rich in humus and consistently moist. To improve existing soil, mix the garden soil with peat or with potting or rhododendron soil.
If you’re going for blue hydrangeas with lasting color, the soil should be free of lime and have a pH value between 4 and 4.5. Practical little home soil-test kids can be found in specialty stores. Different varieties of hydrangea have very similar soil, light, and water requirements, although not necessarily identical.