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Here’s Why You Shouldn’t Use Eggshells On Your Hydrangeas

Many gardeners swear by eggshells as a nutrient-rich fertilizer. The calcium carbonate that makes up 90% to 95% of eggshells is a good source of calcium.

Provides excellent defense for Hydrangea against a wide range of pests and diseases while also strengthening the plant and enriching the soil.

However, remember that not all plants thrive when treated with this fertilizer. The Hydrangea is an example of a plant that does not respond well to eggshell fertilization.

If you want to use eggshells as fertilizer, here’s how to do it.

In this article, you’ll learn why it’s best to avoid using eggshell fertilizer around your cherished Hydrangeas.

To begin, let’s learn about the many ways eggshells can be put to good use.

As was previously mentioned, egg shells are composed of 95% calcium carbonate, which is suitable for regulating the pH of the soil by decreasing its acidity.

In addition, the eggshell contains 27 plant-available trace elements (such as iron, phosphorus, magnesium, zinc, manganese, etc.).

Element100 g chopped shell (fresh)In 100 g (after calcination)
Calcium carbonate35 g30 g
IronUp to 4.2 gUp to 2.5 g
ZincUp to 650 mgUp to 3.3 g
Magnesium410 mg1050 mg
SulfurUp to 1300Up to 1 g
PhosphorusUp to 170 mgUp to 12 g
ManganeseUp to 120 mg420 mg
SodiumUp to 130 mg650 mg
Potassium85 mg20 mg
Source: NCBI

Additionally, eggshells can be used to ward off pests like slugs, snails, and cutworms.

But why don’t Hydrangeas like eggshells if they are so good?

You might be fooled by some wrong information on other blogs written by people who don’t know what they are talking about, but here is the truth.

Flowering hydrangea bushes are pretty big. There are between 30 and 80 different species of hydrangeas. The soil conditions necessary for a healthy Hydrangea plant are pretty specific.

  • Acidity. pH levels between 5 and 5.5 are ideal for hydrangeas.
  • Looseness. Shrubs require sandy, light soil for their roots.
  • Permeability of water. Hydrangeas don’t like to be dry, so they do best in soils that let water through quickly.
  • Nourishment. Soil high in nutrients is ideal for the plant’s growth. This is why seasoned flower growers prepare the soil as early as the fall.

Eggshells can make the soil less acidic, which is why Hydrangea doesn’t like this fertilizer. As I said, eggshells make the soil less acidic, and Hydrangea grows best in acidic soil.

Curling leaves and fewer flowers are two signs of how plants react to a soil that is too alkaline or lacks sufficient nutrients.

It’s important to note that florists can alter the hydrangea flowers’ hue by shifting the soil’s acidity.