How to Mulch Your Garden with Crushed Shells

We gather them at the sea shore, we put them in shadow boxes and we make porcelain replicas to use as soap dishes. Who doesn't love shells? In fact, shells can be much more than romantic bric-a-brac. Using shells for garden mulch can provide unexpected benefits in any climate zone.

Instructions

Difficulty: Moderate

Things You’ll Need:

• Shells, crushed

1. You can purchase crushed shells commercially through a local landscape material supplier, but that can become pricey. A more cost effective option would be to contact your local seafood restaurant and see what you can work out with them to take the empty shells off of their hands. These shells would have to be boiled clean to remove any last bits of shellfish remaining inside. Your garden might appreciate the decaying fish matter but your delicate nose will not, especially if you are mulching in the spring.
   
   If you are using large shells such as oyster shells, you may want to break them up a bit by covering them with a cloth and hitting them with a hammer once or twice. Smaller shells can be used whole.
2. Though the most common use for crushed shell is pave a pathway through your garden, mulching with crushed shell provides the plants with much needed calcium and minerals as the shells themselves decay. This will save money on soil additives over time and for those who are concerned with Green Living, you will have avoided the chemically processed additives completely.
3. As with any mulch, a layer of shells over the top of the soil will prevent weed growth and help to retain moisture in the soil. This is especially useful in hot, dry growing zones where the lighter color of the shell mulch reflects the sun's heat, helping to keep both the plant' s roots and the moisture in the soil cool. Shade gardens in cooler climates benefit from the touch of bright contrast provided by the shells.
4. Use enough shells to make a two inch layer over the area you want to protect. Shells degrade slowly so you shouldn't need to replenish the layer for at least two years.
5. If you decide to feed your plants with compost during that time, you will need to rake the shells out of the way before laying the composted material. Then simply rake the shells back over the area when you are done. Because of it's longevity, crushed shell mulch is best used to protect perennial beds where the soil will not need to be disturbed each spring for new plantings.