Planting Blackberries by National Gardening Association Editors Blackberries need full sun. They aren't fussy about soils, although good drainage is important. If the soil has a good amount of humus, so much the better, but average fertility is all they need. Do not plant blackberries where any other brambles have been growing; diseases can build up over time and one of the easiest ways to avoid problems is to start fresh on a new site. Because wild blackberries and raspberries can harbor diseases and pests, try to keep your garden plants at least 300 feet from any wild relatives. Also avoid planting where any nightshade family members - tomatoes, potatoes, eggplants, peppers - grew in the last 2 years, as they can transmit verticillium wilt to blackberry plants. Planting Particulars Plants should be set out in early spring. If you get your plants from a mail-order company, order them at least a month or two before planting time and indicate the week you'd like the plants to arrive. If you can't plant the day they arrive, keep plants, well wrapped, in a cool place. If they are loose and unpacked, set them temporarily in a shallow trench at the edge of the garden and fill it with soil so the roots don't dry out. Nursery plants may have a 6- or 8-inch dormant cane extending from the root ball. You can use it as a handle in moving the plants and later as a row marker. Set the plants in the ground 1 inch deeper than they were grown in the nursery, then firm moist soil around the roots. Plant upright varieties at least 3 feet apart in the row, with 8 feet between rows. For trailing types, allow 5 to 8 feet between plants and 6 to 10 feet between rows. The plants are relatively drought tolerant, but they'll need a steady supply of water to get them established. In the second and subsequent years, plants need 1 to 2 inches of water per week during fruit development, especially if the weather turns dry and windy, a bit less once the crop is harvested. Drip irrigation is a good watering method for blackberries.