Tips for Mulching Raspberry Plants

Soil Composition

• Before applying mulch, ensure that the soil has the proper composition for adequate draining. Add compost to the soil to improve the texture and lighten an overly heavy soil. If you apply mulch over a soil that does not drain well, you may seal the moisture in and this may contribute to root rot.

Mulch Ingredients

• Reiman Gardens, of the Iowa State University, recommends using grass clippings, shredded leaves, sawdust, shredded corn cobs or wood chips on the soil beneath raspberry canes. Many gardeners have grass clippings and shredded leaves readily available, making these mulch ingredients plentiful and free. If you choose to apply sawdust, allow the sawdust to age for one year before using it and do not apply it thicker than 1 inch or it may prevent air from reaching the soil. Wood chips also make an effective and economical mulch around raspberry canes.

Conserve Soil Moisture

• Because raspberries require between 1 and 1 1/2 inches of water each week throughout the growing season, a layer of mulch can ensure that the canes stay moist in the soil. If raspberries do not receive adequate moisture between blossoming and harvest, the quality of the raspberries may suffer.

Weed Control

• Lay a thick layer of mulch between the raspberry rows for effective weed control. Apply between 4 and 6 inches of grass clippings or shredded leaves to prevent weeds from growing between the rows. Within each raspberry cane row, carefully add mulch over the soil. However, make the mulch within the rows thinner to enable new raspberry canes to emerge through the mulch.

Fertilizing Mulched Raspberries

• The University of Minnesota Extension recommends that you add between 1/4 and 1/2 cup of ammonium nitrate to every bushel of sawdust or wood chips as you apply either of these mulches to the soil beneath raspberry canes. The ammonium nitrate will help the sawdust or wood chips decompose more quickly and it will also replenish nitrogen levels in the soil that may deplete with the addition of either wood product.