To transplant into a garden container or the garden bed, water your plant the night before. Since your plant has been in a box without light or water, it may have some yellowing leaves or show some wilt.
If the soil is dry, water the plant and put her in bright, indirect light for a couple of days. When all danger of frost has passed, you can transition your plant slowly to more direct sunlight. For one to two weeks, start in the morning hours and gradually give it more direct sunshine each day. After increasing the time, this should acclimate to full sun for 6-8 hours per day.
Next, dig the hole twice as wide as the grower pot and the same depth as the grower pot (not deeper). Remove the plant and center in the spot. Add rooting hormone around the roots of the plant. Water in the hole and let drain. If you have clay soils, add compost to enhance the soil consistency with the native soil. Fill around the plant with the combined mix and up to the top of its soil line. Tamp down with your hands to remove any air pockets. Water again around the drip line, being careful not to soak the leaves to help prevent fungus. Keep the soil moist like a wrung-out sponge but not soggy to promote healthy root growth. Check out our water wisely blog on how much to calculate the amount of water your blackberry shrub needs.
Note: Blackberries are the happiest when the pH level is between 5.5 and 7.0. Check your soil with our 3 in 1 plant meter.