The blackberry is an edible fruit that is born on a bush. It isn't a true berry; it is actually an aggregate fruit. The blackberry bush produces flowers in late spring and fruit later in the summer. Blackberries are high in vitamin C, vitamin K and dietary fiber and also rank highly amount fruits for their antioxidants. Hardy to zone 5, it is moderately easy to grow blackberries in Wisconsin. With the right siting and proper care, they will flourish for you.
Select a site that is ideally in full sun. Blackberries will tolerate partial shade but may produce less fruit.
Amend the soil with well-draining, rich garden loam. Use equal parts with your existing soil to make a great soil mix.
Apply manure at a rate of two to three bushels per 100 square feet. Rototill the soil to mix in everything.
Plant your blackberry bush as soon as you can work the soil in the spring. Dig a shallow hole large enough to accommodate the root system and prune off damaged roots. Spread the roots in the planting hole and bury them in soil. The soil should come up to the same level on the blackberry bush as it was at the nursery.
Tamp the soil down to remove air pockets and water the bush to settle the soil.
Space the blackberry bushes 4 to 10 feet apart if they are trailing cultivars and 4 to 6 feet apart if they are erect cultivars. Rows should have 8 to 10 feet between them.
Set up a trellis system for your blackberry bushes. Purchase your trellis at your local garden center or make one with two posts with wires in between the posts.
Fertilize blackberry bushes in early spring when you notice new growth. Apply 5 to 6 pounds of 10-20-20 fertilizer per 100 feet of row.
Cultivate the soil during the growing season to remove weeds and to keep the soil loose. Cultivate to a depth of 1 to 2 inches to prevent root damage.
Water your blackberry bushes with 1 inch of water per week over the entire root zone from mid-June until harvesting is finished. Water more in extremely warm and windy weather.
Harvest your blackberries every three to six days once they begin to ripen. Ripe blackberries are black in color. Put them in a shallow container when harvesting to prevent crushing.