Here are six organic materials you might use to fill up raised garden beds.

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Deborah DeSalvois the owner of Cold Brook Farm in Oldwick, New Jersey.

Any woods with sprouting potential, such as willow and sycamore, must be completely dead before using.

Raised bed with fillers

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And beds may absorb more water with newer logs, DeSalvo points out.

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To counter this, DeSalvo recommends planting anoverwintering cover cropas nitrogen-fixing plants, such as clover.

Raised beds

Deborah and Jason DeSalvo, Cold Brook Farm

Straw

Straw baleswork well as an inexpensive voluminous filler for the bottom of raised beds.

The only caveat is that they decompose completely within a year, which is much faster than logs.

Leaf mold is packed with microorganisms and worms that break down other organic materials.

Raised bed with topsoil

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As they decompose, they add nutrients to the soil.

Add them to your raised bed in the spring.

Ideally, the topsoil layer should be 12 inches deep.

Raised bed

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