Crushed shells can provide a range of advantages for your yard and garden. When used properly, they can add essential minerals, raise pH, improve drainage, and even help deter pests.
Let’s dig deeper into the benefits of crushed shells for landscaping.
Benefits of Using Crushed Shells for Landscaping Applications
There are several ways that adding crushed seashells and other shells can enhance your soil:
Adds Calcium and Other Minerals
One of the most significant benefits of crushed shells is introducing new minerals into your soil, especially calcium. As the shells break down over time, calcium and other trace nutrients are slowly released. This provides a steady supply of these nutrients, which plants need for optimal growth and producing fruits and vegetables.
Increases pH/Reduces Acidity
Most shells are alkaline, so working them into the soil makes it less acidic and raises pH levels, which can be helpful if very acidic soil limits your plant choices. Adding crushed shells moderates pH to open up your options for flowers and edibles.
Provides Organic Matter
Crushed shells add organic material to the soil during decomposition. This organic matter improves soil structure and nutrient retention. Shell particles also create spaces in the soil that allow better air circulation and room for roots to spread.
Improves Drainage
The coarse texture and gritty nature of crushed shells make them perfect for aerating heavy, compacted dirt. Mixing in crushed shells lightens thick, dense soils and allows better drainage. This can mean healthier plants with sturdier root systems.
Deters Pests Such as Snails, Slugs, and Nematodes
Spreading crushed shells as a loose mulch can discourage snails, slugs, and other soft-bodied pests. The sharp, rocky shells bother them, so they stay away from areas protected by a shell layer. Crushed shells may also help control parasitic root-knot nematodes, as the chitin in shells may encourage the growth of microorganisms in the soil that help control these parasites.
Crushed Shells vs Other Popular Landscaping Materials
Before deciding to use crushed shells, consider how they compare to some other common landscaping materials:
Mulch
Mulch made of bark, leaves, straw, or wood chips is best for retaining moisture and suppressing weeds. It gradually improves soil texture as it decomposes. Mulch floats above the soil, while shells are typically mixed in.
Gravel
Gravel offers a decorative ground cover and walkway material. It’s very slow to break down compared to crushed shells. Gravel also doesn’t add significant nutrients or organic matter.
Wood Chips
Wood chips are lighter and easier to spread than crushed shells. They retain more moisture and are faster to decompose. However, shells add more minerals, such as calcium.
Sourcing Crushed Shells
Crushed shells for landscaping use are available either pre-crushed or you can make your own. Some tips to get your hands on this amendment include the following:
Buying Pre-Crushed Shells
Many garden centers and online retailers offer crushed shells for landscaping and soil amendment use. These are often oyster or clam shells sourced from seafood producers. Buying pre-crushed shells is the easiest option.
Collecting and Crushing Your Own Seashells
If you live near a coastal area where seashells frequently wash up, you may opt to gather and crush your own shells. This requires more work but costs nothing. Use a heavy tool, such as a hammer or mallet, to break the shells into nickel-sized pieces or smaller. Wear protective eyewear when crushing shells.
No matter how you obtain crushed shells, ensure they are clean of seaweed, sand, and other debris before using them in your garden. Also, rinse off any lingering salt, which can damage plants.
How to Apply Crushed Shells in Landscaping
Crushed shells have a variety of landscaping uses. Some methods to apply them include the following:
Spreading Evenly Over Soil Surface
Simply scatter crushed shells lightly across your garden beds, lawn, or bare soil areas, which adds organic matter and minerals as the shells mix into the earth. It also deters pests. Spread shells 1 to 2 inches deep for the best effects.
Mixing Into Soil
For quicker nutrient release, plough the crushed shells several inches down into the soil. This works shells deeper into the root zone so plants can fully utilize the nutrients.
Using as Mulch
Crushed shells work well as a type of mineral mulch around plants. While mulching doesn’t improve the underlying soil as much, it supplies calcium and trace nutrients as rain carries them down to the roots.
Shells work best when integrated into the soil, either tilled in or allowed to mix naturally. This offers the full benefits to your plants. But surface mulching still provides pest protection and decorative appeal.
When to Add More Crushed Shells
Determining when your garden needs a fresh batch of crushed shells is easy. Monitor plants for signals such as:
Yellowing leaves or stunted growth show a nutrient deficiency, often low calcium. More crushed shells provide calcium for healthier growth.- If soil pH drops back down, acid-loving weeds may invade. Scatter more crushed shells to elevate pH levels again.
- Plants with damaged roots or root diseases indicate poor drainage. Till in crushed shells to achieve better drainage and aeration.
- Slug or snail damage means it’s time to top-dress garden beds with a new layer of crushed shells to repel the pests.
Adding more crushed shells every 2 to 3 years usually maintains soil nutrition and pH levels. But keep an eye on soil and plants to determine if your garden needs shells more or less frequently.
Revitalize Your Soil with Barclay Earth Depot’s Premium Crushed Shells
Crushed shells offer a wide range of unique benefits for your landscaping soil. From adding calcium to controlling pests, shells can reinvigorate tired gardens and enhance plant health. While shells work well in many applications, they aren’t a cure-all for every situation.
If you aren’t sure whether crushed shells for landscaping are suitable for your project, Barclay Earth Depot can help. Our team of crushed shell experts can assist you in finding the best approach for your needs. We also supply top-quality crushed shells, so contact us today at 941.841.1681 or online to get started on your landscaping project.
