How to Grow Blackberries from Seeds
Blackberries (Rubus spp.), which grow best in U.S. Department of Agriculture plant hardiness zones 5 through 10, are commonly propagated through cuttings or division. This method gives an exact copy of the berry bush. It is possible to grow blackberry shrubs by planting seeds, but the seedlings vary in features. The best time to plant young blackberry seedlings outside is in September, but the germination process begins six months earlier.
Harvest the blackberry fruit. Use fresh berries to gather the seeds, not dried fruit. The germination rate drops when the seeds dry out. Place the fruit in a blender, pulsing on low until the seeds and fruit separate. Strain the berries out of the juice, and pick the seeds out of the pulp with tweezers.
Examine each of the seeds for scratches or nicks. Scratch any seed without damage with a sharp knife. Scarification helps break the strong seed dormancy surrounding the embryo.
Place the blackberry seeds in a resealable plastic bag along with a handful of damp peat moss. Seal the bag, and place in a refrigerator with temperatures around 33 to 35 degrees Fahrenheit. Keep the seeds chilled for 12 to 16 weeks.
Fill seed trays with seed starter soil, and spread the blackberry seeds on top of the soil. Lightly cover the seeds with soil, and place in a warm area. Blackberry seed germination does not require bright light since the seeds are covered with soil. Mist the soil with water in a spray bottle whenever the soil begins to dry out. Once seedlings begin to sprout, move the tray to an area with bright light.
Remove the weeds from a planting area in full to partial sun. Pick a location with good drainage. Spread a 3- to 6-inch-layer of well-rotted compost over the planting area. Dig the organic material into the soil with a shovel. Work the compost into the top 8 inches of soil. This gives the blackberry plants a good source of slow-release nutrients. Smooth the soil with a rake.
Dig holes with a hand trowel only as deep and wide as the seedlings’ root balls. Space the holes out 4 to 6 feet apart. Place the seedlings in the holes, and fill with soil. Gently firm the soil around the brambles so they stand up. Space the rows 10 feet apart.
Water the soil around the base of the blackberry plants until it is slightly muddy. Give the berry plants 1 inch of water each week when there is no rainfall during the summer. Spread 2 to 3 inches of organic mulch around the base of the new shrubs. Mulching benefits blackberry bushes by reducing weed growth, slowing soil moisture evaporation and providing slow-release nutrients. Keep the mulch layer thick throughout the life of the blackberry bushes.
How to Grow Blackberries from Seeds. Blackberries (Rubus spp.), which grow best in U.S. Department of Agriculture plant hardiness zones 5 through 10, are commonly propagated through cuttings or division. This method gives an exact copy of the berry bush. It is possible to grow blackberry shrubs by planting seeds, but …
How to Save and Plant Blackberry Seeds
Blackberries are a delicious fruit with a slew of health benefits. In addition to being high in fiber and vitamin C, the Berry Health Benefits Network lists blackberries as having anti-bacterial and anti-viral properties. All blackberries are perennial in U.S. Department of Agriculture plant hardiness zones 3a to 10b and grow best in full sun and well-drained soil with a pH of 5.5 to 7. If you live in an area that meets the above growing conditions, you’ll want to save some blackberry seeds, so you can grow blackberries from fruit on your own later on.
Saving Your Seeds
Harvest the Berries
Growing berries from seed begins by examining the color of the blackberries, selecting deep purple or burgundy berries. Hold the berry between your thumb and forefinger, then gently twist it off the stalk. Put collected berries in a basket out of direct sunlight and mist them with water to keep them moist.
Blend the Berries
Put the berries in a blender, then hit the “Pulse” button on low speed, blending the berries until the seed is visibly separated from the pulp, or mash the berries with a fork. Pour the fruit into a strainer to separate the juice from the berries. Pick out the seeds with tweezers.
Choose Your Seeds
Select seed that has scratches or nicks. Scrape any other seed with a knife, nicking the surface of it gently.
Prepare a Container
Fill about half of a medium-size clear plastic food container with sphagnum peat moss. Put the seeds in the container, making sure that they are buried in the peat moss. Layer one-half inch of peat moss on top, then put a piece of paper over the container.
Store the Seeds
Put the container in the refrigerator or a room about 33 to 35 degrees Fahrenheit for approximately three months, as recommended by Oklahoma State University. Keep the peat moss moist at all times, misting it with water when it feels dry to the touch.
Planting Your Seeds
Prepare the Soil
Fill a nursery flat with seed-starting soil mix. Spread the seed on top of the soil, one seed per compartment, then sprinkle a thin layer of soil on top of the seeds. Mist the soil with water and place the nursery flat in a sunny, warm area. Keep the soil evenly moist, misting it with water when it feels dry to the touch, as this is the best way to grow blackberries from seed.
Add Some Compost
Loosen the soil of the planting site to a depth of 6 inches, removing any weeds. Spread 2 cubic yards of compost per 100 square feet over the planting site, then till it to a depth of 6 inches. Smooth the soil with a rake.
Provide Adequate Sunlight
Harden off the seedlings 10 days prior to planting, placing them outdoors in a shady area for 3 to 4 hours each day. Increase the amount of sunlight and hours spent outside daily.
Prepare the Hole
Dig a hole the same depth and diameter as the seedling was planted in the nursery flat. Space the holes 4 to 6 feet apart for trailing varieties, 2 to 3 feet apart for erect varieties and 5 to 6 feet apart for semi-erect varieties. Alabama A&M University Extension recommends spacing the rows 12 feet apart.
Add the Seedlings
Take the seedlings gently out of the nursery flat, handling them by the their roots and the soil. Put the seedling in the hole, then cover the roots with soil. Tamp the soil down, then saturate the soil around the base of the seedlings.
Cover in Mulch
Spread 2 to 3 inches of organic mulch around the base of the seedlings. Irrigate consistently, making sure that the soil stays evenly moist.
How to Save and Plant Blackberry Seeds. There are three main categories of blackberry: erect, semi-erect and trailing. Erect blackberries have stiff, upright canes, and semi-erect blackberries have arching canes. Trailing blackberries are low-growing and climbing, and they offer a stronger aroma and fruit than erect …