Even though your thoughts are turning to pumpkin spice and autumn beauty, it’s a good time to prepare your soil for the spring garden so next year’s perennials will be strong and healthy. 

Because it’s still mild in the fall, most plants are experiencing new root growth before they go dormant. Working the soil now gives them two seasons of mild temperatures (fall and upcoming spring) before the heat and drought of summer returns. Establishing a strong root system in the fall with the right soil will protect the plants during the cold winter.

Working the soil now will also produce the lush colors of perennials next year.

This is particularly important for hydrangeas, with their unique pink and blue colors. Hydrangeas have the unusual ability to change their flower color.

Hydrangeas get their vibrant color based on the pH level of the soil. (The pH in anything means potential of hydrogen.) A lower pH allows plants to absorb the nutrients they need to flourish and grow.

The higher the concentration of pH in the soil, the more alkaline it is and the pinker the flowers. To make hydrangeas turn blue, or to keep the blue ones from fading to pink next year, increase the acidity of the soil.

Here’s a simple test. Place a handful of dirt in a small container. Pour distilled white vinegar over it. If the solution fizzes, the pH level is high and your soil is alkaline. If it doesn’t fizz, then the soil is neutral or acidic, and you won’t have to do much to keep your hydrangeas blue. (You can also purchase a pH tester kit online.)


Changing the soil pH

To make your soil more acidic, add organic materials such as coffee grounds, crushed eggshells and ground-up orange peel. Work the mixture into the ground around the base of the hydrangea and then water. As they decompose, the materials will add aluminum to the soil, making it more acidic. 

The acidity of the soil will slowly increase, and by next year your hydrangeas should look a lot more blue. 

If you prefer pink hydrangeas, the way to make your soil more alkaline is to add garden lime. It is available at local nurseries.

Hydrangeas aren’t the only acid-loving plants that will thank you with rich colors in the spring. Others include azaleas, rhododendrons, daffodils and begonias. Edible plants such as strawberries, tomatoes and cucumbers also love acidic soil.

If your acid-loving plants are isolated among other non-acid plants, it may not be practical to amend the soil. In that case, it’s best to fertilize with products such as Miracid. 

But as the weather cools and you want that extra cup of coffee, save the grounds and toss in your soil. You can then settle into fall and have happy plants too. MKE

Sources: Gardenista.com, thespruce.com, Action Garden Center