Sweeten the Home Garden with Blackberries

New Mexico gardeners might consider growing blackberries this season. They thrive in New Mexico's climate and soils, and March is the time to plant them.

Blackberries grow best in full sun. They do well in most soils but they prefer deep, well-drained sandy loams with a pH (acid content) of 6.5 to 7.5. Add 1 to 2 inches of compost and 1 to 2 pounds of phosphorus (P205) fertilizer per 1000 square feet for good root development during the first growing season. Do not plant in areas with perennial weeds like bindweed.

Plant only certified nematode- and virus-free plants available at most nurseries from late February to early April. Soak roots in water for an hour before planting.

Dig planting holes 6 inches deep. Cut plant tops back to 6 inches long before planting. Prune any broken roots. Set new plants at the same depth or slightly deeper than they were at the nursery. Cover roots with moist soil, firm the soil around the plant and irrigate immediately.

Blackberries have perennial root systems and biennial canes. Canes produced during the first growing season produce fruit the following summer. The canes die back to ground level during the winter. Prune dead canes to make room for new growth in the spring.

Train erect and trailing blackberries to a trellis during the first growing season. Removing the top third of all canes can slightly reduce yields but will result in larger berries.

As new plants develop the first year, apply nitrogen fertilizer at a rate of one-fourth to one-half pound of nitrogen per 1,000 square feet. Apply in a band 9 to 12 inches from the plants, between 4 and 6 weeks after they are established. Lightly mix the nitrogen fertilizer into the soil. Irrigate immediately after application.

Blackberry varieties may have thorny or smooth canes. 'Kiowa' has erect thorny canes with very large fruit. 'Choctaw' is an early thorny variety with small seed. 'Black Satin' is an early mid-season variety with smooth stems and semierect canes. All do well in New Mexico.

For more information, please visit New Mexico State University's Cooperative Extension Service (CES) Publications website.