Hydrangeas are perennial shrubs that boast large, showy flowers. There are 23 species of hydrangeas in the world, but only five of them are popular in the United States. While many beginning gardeners may think that hydrangeas are difficult to grow, the reality is that they grow quite well as long as you plant hydrangeas in the right soil and in the right location.
Choose a location in your garden that gets some morning sun and a bit of afternoon shade. The cooler your climate, the more daily sunlight your hydrangea plant will need. Most hydrangeas thrive in at least five hours of sun per day.
Clear a large area for your hydrangea plant with a rake. The area should be a minimum of 4 feet wide. Note that hydrangeas can grow quite tall--some even up to 5 feet or more--so do not plant hydrangeas under trees or anything else that will throw too much shade onto the plant.
Use a soil-testing kit to determine the pH level of your soil. Soil that has a lower pH level (5.5 and below) is considered to be acidic. If there is aluminum naturally or artificially present in acidic soil, the blooms of this perennial shrub will be purple or blue year after year. Otherwise (or if your soil is alkaline), they will be pink.
Amend the soil. It should be well-drained and not too heavy. If your soil is heavy or is clay, add pine bark mulch to loosen it up. Mix the mulch with the soil to a depth of around 4 inches.
Dig a hole about twice as wide as the root ball and exactly as deep as the root ball is long. Loosen the hydrangea's roots, then place the plant in the hole and fill it in with the soil. Surround the hydrangea plant with a 1-inch-deep layer of organic mulch.
Keep the soil moist. While hydrangeas do not do well in standing water, they do like rich, moist soil. Fertilize the hydrangea once in the summer and once in late fall with a slow-release, balanced (10-10-10) fertilizer.