How to Grow a Thornless Blackberry Bush

Select a nursery thornless blackberry cultivar adapted to your region. "Apache," "Arapaho" and "Navaho" are three examples of varieties without thorns. Your local nursery and cooperative extension staff can tell you which plant is the best for where you live.

Select a sunny planting site. If wind is a problem, install a commercial garden windbreaker. Another option is to position the bush where a hedge protects it from strong hot and cold winds, which injure the berries and canes.

Remove weeds and other vegetation from the planting site with a hoe.

Test your soil's pH. Garden shops sell kits, and your local extension office also has information on soil analysis. The ideal pH for growing blueberries is 5.5 to 6.5.

Break up the soil to a depth of 12 inches and incorporate 5 pounds of dolomitic lime per 100 square feet to raise the soil's pH, or apply 1 pound of elemental sulfur per 100 square feet to lower it.

Plant blackberry bushes in the dormant season at the same depth they had been kept in at the nursery. Trim the stems to 6 inches before placing the bush in the hole. Separate blackberry bushes by 3 feet.

Irrigate your bush immediately after planting it. Install a soaker hose near its base so the foliage stays dry. Don't water it again until early spring. Keep the soil consistently moist throughout the growing season by watering your bush as frequently as every other day. Increase the interval when it rains.

Apply 1/4 pound of a 10-10-10 fertilizer per plant in late spring in the the first growing season. The following years, apply 1/4 pound of fertilizer per bush in winter and again after harvest.

Prune erect and semi-erect blackberry canes to keep them at 30 inches in the first growing season. This promotes new shoots to form for a denser bush.

Cultivate regularly to prevent weeds, but don't dig deeper than 2 inches with your hoe to avoid injuring the plant's shallow root system. A 2-inch layer of pine bark also chokes weeds and conserves moisture.

Contact your cooperative extension office for help to identify and control pests and diseases. Get advice on the least toxic alternatives, as anything you spray on your crop will end up in your bloodstream when you eat the berries.

Harvest blackberries by hand as they ripen. Gathering season depends on the cultivar.