Key Takeaways

  • Nurture vibrant hydrangeas with the right potting soil. It should include organic bark, compost, alternatives to peat moss, perlite, lime, and fertilizer.
  • Organic bark, such as hardwood or softwood, serves as a favored mulching material for trees and shrubs.
  • Peat moss alternatives like coconut coir, vermiculite, and wood fiber are eco-friendly options that are not acidic and provide nutrients for plants.

If you aim to nurture vibrant and thriving hydrangeas, the journey starts with the soil beneath their roots. Whether you're a seasoned gardener or just starting, understanding the unique needs of hydrangeas ensures vibrant blooms and healthy plants.

Get ready to elevate your hydrangea gardening experience and discover the best potting soil for your hydrangeas to unlock their full potential.

The Best Potting Soil for Hydrangeas

Nutrient-rich soil blends

Two hydrangea plants planted in large pots in the front yard
Image credits: Ben Kerckx via Pixabay

Hydrangeas prefer rich, well-draining soils to thrive. The ideal soil should include:

To make an all-purpose soil mix, blend together:

6 gallons

Sphagnum peat moss/coconut coir

5 gallons

Perlite

6 gallons

Compost

¼ cup

Lime

1½ cups

Granular organic fertilizer or a homemade fertilizer blend containing 2 cups of rock phosphate, 2 cups of greensand, ½ cup of bone meal, ¼ cup of kelp meal

You can use humic acid for your hydrangeas if you can't find lime. Humic acid is an organic substance that plays an essential role in water retention, which is important for the well-being of hydrangeas. To use humic acid, mix 1 tablespoon of humic acid with 1 gallon of water and use it to water your hydrangeas.

1. Organic Bark

shredded bark mulch in different sizes

Barkwood mulch, a byproduct of the lumber and paper sectors, is made from the bark of both hardwood and softwood trees.

  • Popular for its organic composition, it serves as a favored mulching material for trees and shrubs.
  • Hardwood examples like maple, oak, and elm come in various sizes and textures, extending from fine shreds to substantial nuggets.
  • Similarly, softwood alternatives, including pine, redwood, and fir, contribute to the array of choices available for gardens and landscapes.

2. Compost

Person holding a pile of compost in their hands

Compost is a natural fertilizer made from organic materials, such as kitchen scraps, disease-free garden waste, and manure. It is rich in nutrients and beneficial microbes that can improve the health of your plants and soil. Compost:

Overall, compost is a natural and sustainable fertilizer that can help your plants grow stronger and healthier.

3. Peat Moss Alternatives

A person holding peat moss in the garden.

Peat moss is a decomposed version of sphagnum moss and has been a common and widely used resource since the 1950s. Yet, in recent times, the surge in eco-conscious consumers has led to an increased interest in alternative options. That said, harvesting peat moss isn’t eco-friendly because:

  • Peatlands store a large amount of carbon, which, when harvested, release carbon into the atmosphere contributing to greenhouse gas.
  • They’re important habitats for many animals and birds
  • Peat moss is not renewable and not a sustainable resource.

Besides that, peat moss is acidic, with a pH between 3 and 4, making it less ideal for plants that thrive in neutral or alkaline soils. With a lack of nutrients and a growing awareness, many people opt for peat moss alternatives like coconut coir, vermiculite, and wood fiber.

It takes peat moss hundreds of years to grow as it has a slow growth rate of ¹⁄₃₂ inch per year.

4. Perlite

perlite spread out on a yellow surface

Perlite is a lightweight, porous volcanic rock that is often used in horticulture. It is made by heating volcanic glass to high temperatures, which causes it to expand and become popcorn-like. Perlite is inert, meaning it contains no nutrients or salts. However:

  • It helps improve drainage
  • Increases soil aeration
  • Reduces the risk of compaction and
  • Improves water retention.

5. Lime

Garden limestone with a spade for mixing it in

Lime is a natural substance that is commonly used to raise the soil’s pH. It can improve nutrient availability by increasing the soil’s pH, giving plants the ability to absorb the soil’s nutrients more easily. It also helps reduce the soil’s acidity, which is beneficial for plants that thrive in alkaline soils.

Lime is also a good source of calcium and magnesium, essential plant nutrients.

6. Fertilizer

Fertilizer for pear tree

Both store-bought and homemade fertilizers can have benefits for potting soil. Store-bought fertilizers are typically formulated to provide plants with a balanced blend of essential nutrients, such as nitrogen, phosphorus, and potassium. They are also convenient to use, as they come in pre-mixed formulas that can be easily applied to potting soil.

Homemade fertilizers, like coffee grounds, eggshells, and banana peels, can also be a good option for potting soil. However, it is important to note that they may not be as balanced as store-bought fertilizers. Additionally, some homemade fertilizers, such as compost or manure, will need to be aged before they are used on plants. Here is a summary of the benefits of store-bought and homemade fertilizers in potting soil:

Store-bought fertilizers are:

  • Convenient to use
  • Formulated to provide plants with a balanced blend of essential nutrients
  • Available in a variety of formulas to suit different plant needs

Homemade fertilizers are:

  • More cost-effective than store-bought fertilizers
  • More environmentally friendly than store-bought fertilizers
  • Can be made from readily available materials, such as food scraps and yard waste

Ultimately, the best type of fertilizer for hydrangeas depends on your individual needs and preferences. However, as a general approach, you can mix 2 cups of rock phosphate, 2 cups of greensand, ½ cup of bone meal, and ¼ cup of kelp meal together and use it as granular fertilizer for your hydrangeas.

If you are looking for a convenient and easy-to-use fertilizer, then a store-bought fertilizer is a good option. If you are looking for a more cost-effective and environmentally friendly option, then a homemade fertilizer may be a better choice.

Here are some tips for using fertilizers in potting soil:

  • Test your soil and your soil pH before adding fertilizers.
  • Do not over-fertilize your hydrangeas, as this can damage them. The best time to fertilize your hydrangeas is in the spring after you prune them.
  • Water your hydrangeas regularly after fertilizing them. This will help to prevent the fertilizer from burning the roots of your plants. Hydrangeas need 1 inch of water per week.
  • If you are using a store-bought fertilizer, test it on a small area of your plant first to ensure it is not harmful. Wait 24 hours to see a reaction, and if you don't see burned or droopy leaves, you can follow the instructions on the fertilizer package.

To improve the soil's drainage, add inorganic amendments like vermiculite or organic ones like coir or earthworms to prevent root rot and premature plant death. If vermiculite or coir aren't available, you can add alternatives like coarse sand, charcoal, or perlite.

Don't add fresh manure to your hydrangeas; it can burn your plants. Always use well-aged manure and rotted compost to fertilize your plants.

The Perfect Pot for Hydrangeas

Picking friendly containers

You can grow hydrangeas in containers but need a large pot to accommodate their growth. Ideally, you'll need a container at least 18 inches in diameter to give your plant enough space to stretch and grow.

Since hydrangeas need at least 1 inch of water every week, growing them in plastic containers will help keep the soil moist, whereas clay pots will absorb moisture and dry the soil faster.

Ensure your pot has drainage holes, and if it doesn't have some, drill three to four ¼ inch holes at the base of your pot to allow drainage.

Choosing suitable potting soil for hydrangeas is crucial for their well-being. A mix that provides good drainage, humic acid, and essential nutrients supports their growth and enhances soil quality.

With the right potting soil, you can unlock the full spectrum of colors, nurture healthy blooms, and transform your gardening experience into a flourishing showcase of botanical beauty.

Don't forget to share this article with your family and friends looking for the best potting soil for their hydrangeas!