Putting Pine Mulch on Blackberries

Benefits

• Using a pine mulch in your blackberry patch can double soil moisture levels and reduce the time you spend pulling weeds by 30 percent, according to Cornell University Extension. Pine mulches also keep the soil warmer in the winter -- an important consideration if you're growing blackberries north of USDA zone 6, where they tend to suffer more cold injury. Blackberries grow best with a soil pH between 5.5 and 7.0. Pine needles have a slightly acidifying effect, making them an ideal choice if you have alkaline soil

Types

• When it comes to pine mulch, you have several options, all of which have potential benefits and drawbacks. Shredded bark mulch is finely milled and spreads easily in the blackberry patch. It resists compaction and stays in place. Bark nuggets also resist compaction, but they tend to move in rainy or windy conditions. Pine needles, sometimes sold commercially as pine straw, make an attractive, long-lasting mulch. Pine needles lock together so they stay in place without compacting the soil. They're inexpensive to buy or free if you have the trees on your property.

Installation

• Regardless of the type of pine mulch you use, spread 2 to 3 inches of the mulch over the soil in your blackberry patch. The mulches slowly decompose or become thin with time. You'll probably need to refresh the mulch every one to three years. Pine mulches keep the soil warmer in winter, and cooler in the summer. If you live in a cold area, pull the mulch back in the spring so the soil can warm, encouraging strong new growth.

Considerations

• Occasionally, commercially processed mulches aren't handled properly and ammonia and other toxic chemicals can build up in them. These mulches smell like ammonia, rotten eggs or vinegar. Avoid buying mulches with a strong odor. They can damage or even kill your blackberry plants. Additionally, most pine mulches take some nitrogen from the soil as they break down. Take this into consideration as you fertilize your blackberry patch. Landscaping mulch or wood chips, which is often available free from municipalities, makes an attractive, economical mulch. Keep in mind, though, that this mulch can sometimes harbor disease or plant seeds.