Do Eggshells Actually Help Your Roses Grow? Here’s What a Gardener Says

Sprinkling crushed eggshells into planting holes is often recommended as a natural gardening hack to boost garden soil, especially for flowering plants like roses. But do they actually make a major impact on your plant’s health?

To separate fact from fiction, we spoke with a plant scientist about whether eggshells for roses actually work and the reliable alternatives that can help cultivate long-lasting, beautiful blooms.

Do Eggshells Help Roses Grow?

While eggshells contain calcium carbonate, according to plant expert Heather Zidack they may not be a consistent or predictable source of this essential plant nutrient.

“Calcium plays an important role in developing plant cell walls, which support the plant’s overall structure and contributes to stem strength and healthy growth,” Zidack explains. “Strong rose stems are important especially when the flowers are harvested for cut flower use in bouquets.”

However, eggshells decompose very slowly, meaning nutrients are not immediately available to plants. Soil conditions like pH and moisture also affect how quickly shells break down and become absorbable.

“Calcium is only one piece of the overall nutritional puzzle, and it’s important to make sure soil nutrition is balanced for healthy plants,” Zidack says. “Soil tests are recommended every 2 to 3 years and are available through most Land Grant Universities/Cooperative Extension programs.”

Are There Other Benefits of Eggshells in the Garden?

Even if eggshells are unlikely to be the ideal calcium amendment for roses or other plants, they may still benefit your garden in some ways.

Adding crushed shells to your compost helps recycle kitchen waste while slowly contributing minerals to the nutrient-rich “black gold.” Eggshells are often also added as grit in vermiculture bins to aid worm digestion by helping to break down organic matter.

Some gardeners use eggshells with the goal of preventing blossom end rot in susceptible plants like tomatoes and peppers.

“While this disorder involves calcium, it is more often related to calcium uptake and movement within the plant,” Zidack says. “It can be a sign of inconsistent watering disrupting uptake, rather than simply a lack of calcium in the soil.”

If you crush up the eggshells, they can even be used to deter pests.

How to Apply Eggshells to Your Roses

If you plan to use eggshells around your roses after a soil test reveals a calcium deficiency, finely grind them first as the smaller particles break down faster. You can do this using a coffee grinder.

Zidack recommends adding the ground shells to compost rather than directly to the soil, especially given that there are few scientific sources recommending a rate of application.

“[This] has been found to be the most effective method of releasing the valuable nutrients,” Zidack says. “When you next top-dress with that compost, you will [also] be adding many more nutrients that are just as essential.”

More Effective Sources of Calcium for Roses

If a soil test reveals a calcium deficiency, there are faster-absorbed and more reliable forms of this nutrient than eggshells.

Zidack says lime, dolomitic lime, gypsum, and bone meal are all suitable alternative sources. However, some of these amendments can also change soil pH, which is why testing your soil first is important.

“Whenever considering these products, always read the label in full and check with your local cooperative extension office for information regarding appropriateness of said application,” Zidack says.

7 Other Ways to Help Your Roses Grow

While eggshells may add calcium to the soil around your roses in small quantities, appropriate overall care and growing conditions are critical to cultivate healthy blooms. Follow these simple tips to help grow rose bushes that produce stronger stems, healthier foliage, and bigger blooms.

• Plant your roses in a location that receives at least six hours of direct sunlight daily.
• Water roses deeply to encourage strong root growth and healthier blooms.
• Fertilize your roses using a balanced formula in the spring after the danger of frost has passed.
• Mulch around rose bushes to retain moisture and keep weeds at bay.
• Prune your roses annually to improve airflow and promote healthy, new growth.
• Avoid planting your roses too close together, as overcrowding can increase mildew and pest problems.
• Test your soil every few years before adding amendments, as this helps to correctly identify nutrient deficiencies.