Growing your own blackberries for the most delicious desserts, jams, and juices is easy and can be done even in the smallest garden areas. While traditional varieties of blackberry have a reputation for being rambling, thorny monsters, newer types are low-maintenance without compromising yields. Thornless and shrub types of blackberries are great to plant alongside other berry crops and ornamental shrubs as part of an informal flowering hedge. They also grow well in mixed planters to support a changing cast of annual seasonal color.
Blackberry varieties are fully winter hardy in USDA zones 5-9 and typically need a certain length of time below 40 degrees F to produce the best crops. These shrubby perennials also require full sunlight and well-draining soil. The best way to water blackberries is with drip irrigation or soaker hoses, which direct water to the root system instead of to the foliage or developing berries.
The average bloom time differs depending on where the plants are grown. Blackberries in zones 8-9 will flower sometime in May with fruit by June. In cooler climates, blackberries usually bloom by June and fruit late in the summer or even early fall.
Shrubs To Plant With Blackberries
Gardeners often ask if growing multiple cane fruits (blackberries, raspberries, etc) together in a small garden will result in cross-pollination or changes in the fruit quality. The good news is that the majority of cane fruit is self-fertile and not likely to result in inferior hybrids. Planting other cane fruits, blueberries, hazelnuts, or grapes near blackberries will only increase the chance of successful pollination for each berry. Even though each plant pollinates itself, a pollinator is needed to efficiently move the pollen from flower to flower on the bush. Poorly pollinated blackberries result in misshapen or crumbly fruits, not suitable to eat.
Blackberries can be planted amongst ornamental shrubs that flower early for the same pollinator boat effect. Good choices include hollies, dogwood, serviceberry, and mock orange, as they typically bloom for long periods during the spring and early summer.
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Perennials To Plant With Blackberries
Perennials are a great choice for ground covers in a permanent planting area like berry patches. Low-growing ajuga, violets, thyme, or creeping Phlox will suppress weeds and attract pollinators when in bloom. Taller growing perennials are perfect for adding color and attracting pollinators. Look for early summer bloomers like iris, dianthus, and false indigo. These plants can be grown in the general area of blackberries and do not need to be right next to the shrubs to be effective.
Blackberries trained on cordons or trellises may benefit from facer plants that help to hide any bare lower canes. Any well-behaved perennial that prefers well-draining soil and partial to full sun can be used for this purpose. Herbs like comfrey, lavender, or sage would all make for an interesting contrast to blackberry canes.
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Annuals To Plant With Blackberries
Shallow-rooted annuals work well as ground covers that can be changed at the whim of the gardener. Some of the best annuals for color and form include sweet alyssum, bacopa, petunia, and creeping zinnia. These annuals have a long bloom time to attract beneficial pollinators to your blackberry plants.
Best Companion Plants For Blackberries in Containers
Smaller growing varieties of blackberries are perfect for a container garden. Choose a container with enough room to comfortably fit the blackberry and a few shallow-rooted annuals to create a decorative, yet low-maintenance display. Easy annuals, such as calibrachoa, petunia, lobelia, and trailing verbena will attract plenty of pollinators while adding a dose of color to first frost.
Keep regular fertilizing to a minimum by applying a granular time-release feed at the time of planting. The granules will break down over time, releasing a steady level of nutrients to support both good flowering and sturdy growth for all of the plants.
Plants Not To Grow With Blackberries
Most plants grow well alongside blackberries. However, you may want to avoid planting blackberries with other members of the Rosaceae family (e.g. roses, apples, pears, strawberries, etc). This family is susceptible to deadly soil-borne diseases like verticillium wilt and anthracnose, and adjacent family members can pass pests and diseases back and forth. Do not replant a rose plant in any spot in the garden where a blackberry has died of these diseases since the contagion can remain in the soil and may infect the new plant.
Best Plants To Grow With Blackberries
Blackberry bushes grow best with other shrubs, perennials, and annuals that bloom prolifically and attract beneficial pollinators. Mason bees and honeybees are easy to attract but the best pollinators are the native ground-dwelling bees, cutleaf bees, and hoverflies. These super pollinators can be supported by growing a wide range of plants native to your region, including violets, hollies, asters, goldenrods, sunflowers, and dogwoods.