Blackberries are a part of the Rubus genus and are sometimes referred to as dewberries (see References). Types of blackberry varieties include loganberries, marionberries and boysenberries. Blackberries are easy to grow from seed in a home garden, but they also very susceptible to insects and disease. Before planting your blackberry seeds, determine a location that has well-drained soil and receives plenty of direct sunlight. Blackberries are commonly purchased as seedling plants from a nursery and not typically started from seed. However, you can purchase the type of cultivar seed you want at your local nursery or garden store and prepare the seed for germination.
Wash the blackberry seeds in cool running water and then place them in an airtight container. Set the container in your refrigerator for two to three days.
Dig a 1-inch deep hole in a 14-inch diameter pot filled with potting soil and add two to three seeds to the hole. Cover the hole with the soil you dug up and water immediately with 1/2 cup of water.
Place the pot on a window sill where sunlight will reach the plant. Continue watering the plant every day with 1/2 cup water. You should start to see the seedling sprout within 4 weeks.
Mix a 2-inch layer of organic material into the soil bed of where you'll be transplanting the seedling outside. The organic material can consist of dead leaves, grass clippings and manure.
Apply at least 4 cups of nitrogen fertilizer to ever 100 square feet of soil during late fall. The fertilizer will help to break down the organic material in the soil.
Dig a 2-inch deep hole in the soil bed and add the seedling. Cover the seedling with the soil and make sure that the root ball remains at soil level. Water only three to four times a week or whenever the soil is severely dry.