You probably already know that the type of soil hydrangeas grow in can affect their color, but there’s a lot more to think about when choosing the best type of soil for these beautiful blooms. What is the best soil for hydrangeas? Let’s take a closer look.
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Soil structure refers to what actually makes up the soil, which affects things like how it holds water and how well it supports a healthy ecosystem.
For hydrangeas, you want a soil that holds moisture but drains well so that the roots get the water they need without being oversaturated. Plus, soil that drains well tends to be lighter and airier, and it’s easier for the plants to develop a strong, healthy root system.
Soils with a lot of organic matter are also ideal for hydrangeas. Organic matter supports the growth of beneficial bacteria and things like earthworms that increase the availability of nutrients so your hydrangeas can use them better.
Earthworms play another role in the health of your soil. They create channels as they worry their way through. These channels break up heavy soils, making it easier for the plant’s roots to grow. So, adding organic matter is a great way to lighten and aerate soil that is too compact.
One of the things you must consider when growing hydrangeas is the soil pH. These plants can grow in either acidic or alkaline soil, and some types change color depending on the pH. Bigleaf hydrangeas grow pink when the soil pH is over 6.5 and blue if it’s under 6.5.
It might not matter to you what color the blooms are, but if you want your bigleaf hydrangeas to grow a certain color, pay attention to the pH of the soil you choose.
Loamy Soil is Best
The best soil for hydrangeas is loamy soil. You may have heard it described as friable. Friable means that the soil has a crumbly texture, which is ideal for aeration, drainage, and root growth.
Loamy soil is basically the best of both worlds. It’s usually a mix of clay and sand with just the right amount of organic matter. But, if the soil in your yard is sandy or clay, don’t worry. There are some things you can do to improve it.
What About Sandy Soil?
Sandy soils are not ideal for hydrangeas. Sand lets water soak through the soil too quickly, and the water drains away before the roots of the hydrangea can absorb what they need. This type of soil is low in nutrients, too, and your hydrangeas may not grow as strong or produce as many blooms.
If the soil in your yard is sandy, don’t worry, there are things you can do to improve it. Add plenty of organic matter, like compost, to add a boost of nutrients. You may need to dig out and replace most of the sandy soil to accommodate the hydrangea’s roots. They typically spread about 18 inches wide and 6 inches deep.
In the spring, add a layer of mulch to help keep moisture in the soil throughout the growing season. You should also continue to add compost to keep the sandy soil rich, but don’t place it too close to the base of the plant.
Instead, add it around the perimeter where the roots can get the benefit of the nutrients without being exposed to too much moisture.
If you keep up with it and continue to add amendments to improve the quality of the soil, your hydrangeas should thrive, even though your soil was originally sandy.
What About Clay Soil?
Clay soil is a little more difficult to amend than sandy soil, but it is possible to improve it.
The biggest problem with clay soil is that it’s very heavy. It retains moisture and is very compact, making it hard for roots to push through. Unfortunately, this is an ideal combination for root rot, so you have to make some changes if you want your hydrangeas to thrive.
The first thing you will need to do to improve clay soil is to dig it out and replace some of it with compost. Dig down about 10 inches, then add some sand at the bottom to facilitate drainage. This area is where the roots of the hydrangea will sit, and you don’t want them to sit in pooling water.
Make sure you also dig about 18 inches wide to accommodate the roots of the hydrangea. Fill the hole with compost or other organic material to help break down and aerate the firm soil.
During the growing season, remember that clay soil holds onto water, so you may not need to water your hydrangeas as much as you would in other types of soil. Clay soil is usually dense in nutrients, which means you may not need to add much fertilizer. The organic amendments will help ensure that the nutrients are released from the soil so the plant can easily use them.
Loamy soil is the best for hydrangeas. It’s essentially the ideal balance between clay and sandy soils, and it creates the best environment for the roots to spread and blooms to thrive.
That said, as long as you understand what your hydrangeas need, amending sandy or clay soil is possible.
Sandy soil needs plenty of organic material and compost to help it retain moisture. Clay soils also need organic material to help break down and aerate the soil so that it drains easier and releases the necessary nutrients.
So, loamy soils are best, but if that’s not what you have, don’t worry. Hydrangeas can thrive in any soil if you use the right amendments.