Ray Glendering, superintendent at HARC, scans the row of pine needles ready for harvest.

On a sunny, spring morning, Ray Glendening and his crew at CAFNR’s Horticulture and Agroforestry Research Center (HARC) harvested a little-known crop in Missouri—pine straw.

The harvest is the result of successful research breeding pitch pines, which have cold tolerance, with loblolly pines, which have long needles necessary for good mulch. Pitch/loblolly hybrid pines offer a market to Missouri landowners for both wood and pine straw, a multi-million dollar landscaping mulch crop in the southern states and the top choice for landscapers there.

Since the pine straw needle is actually a leaf, it benefits the landscape in much the same way decomposing leaves benefit the forest floor by recycling nutrients and maintaining soil organic matter. Hardwood bark mulch, on the other hand, when used in excess, can cause a buildup of calcium and potassium in the soil, increasing pH and causing an imbalance in soil minerals that can interfere with nutrient uptake.

The minerals in pine needles are balanced so their decomposition does not create an imbalance in the soil. Additionally, hardwood and pine bark mulch can wash away in a strong rain. Pine straw knits together and holds in place during heavy rain, helping to prevent soil erosion.

Balancing Pasture and Pine

Pine straw mulch is just one resource that can benefit a landowner by planting pines. At HARC, the pine stands are part of a silvopasture system where cattle graze in the alleyways between the trees. In a mature stand where trees are more than 10 years old, spring and fall forages of alfalfa and orchard grass, provide nutrients for HARC’s cattle herd, said Glendening, superintendent at HARC.

During the early stages of pine growth, most of the value in the land will be in forage quality. As trees mature, the value balance shifts slightly to the pine straw harvest and pine logs. To ensure that value, it’s important to protect young pines from cattle. At HARC, they shield the trees with welded-wire cages for the first 5-7 years.

Seeds of the Pine Industry

The University of Missouri Center for Agroforestry and the MU department of horticulture are working toward creating a pine straw industry in the state of Missouri through research, product development and education designed to encourage producers, retailers and consumers to adopt the use of this renewable, sustainable, natural mulch material.

Recently, Glendening gave a presentation on pine straw to the Discovery Garden Club in Columbia. “They were really surprised by all its uses and said they wanted to come out and get some,” he said.

HARC sells the bales wholesale for $5.50 per bale, and they retail from $8-10 per bale. On a mature pine stand, Glendening harvests around 200 bales per acre, so planting pines can be a lucrative investment for Missouri landowners. For tree health, it is best to harvest only a portion of the plantation in a given year to allow trees to benefit from needle accumulation between harvests.

Researchers at the Center are creating a seed orchard by grafting the best genotypes of the pitch/loblolly hybrid onto root stocks. In a few years, Missourians will be able to use the seed created to plant their own pine straw-producing tree plantation, windbreak, alley cropping practice or silvopasture enterprise.

To learn more, attend HARC’s Field Day on June 30.