If your neighbors grow raspberries, and if they’re very nice neighbors, you might have tasted these sweet, juicy fruits fresh off the branch in midsummer.
If you have, you understand why people cultivate this prickly, ungainly, colonizing shrub—in fact, you’re probably coveting them yourself. There’s nothing else remarkable about Rubus idaeus—the flowers are small, white, single blossoms; the leaves are toothed and green; canes are generally thorny and floppy; and it requires staking and annual pruning. But those soft-crunchy, juicy-drippy, handful-of-candy fruits will have you whistling as you work.
Common name: Raspberry, red raspberry
Botanical name: Rubus idaeus
Plant type: Shrub
Zones: 3 to 9
Height: 4 to 10 feet, depending on cultivar
· Sun: Full sun to part shade
· Soil: Rich and slightly acidic
· Moisture: Average to moist, and well-drained.
· Mulch: Mulch to preserve moisture in the soil.
· Pruning: Pruning strategy for both summerbearing and everbearing raspberries depends on whether you want one or two crops of fruit. The easiest method—cutting all the canes to the ground each fall—means you’ll have all new canes the following year, which will bear fruit in the top third of the cane in the late summer. If you let those canes stand another year (the second method), they’ll bear fruit again, on the bottom two-thirds, and then they’ll die and you can cut them down. Each year, cut off small, weak shoots and remove suckers that creep outside your garden bed.
· Fertilizer: Use well-rotted cow manure or ammonium nitrate.
· By seeds and by basal shoots (suckers).
Pests and diseases
· Vulnerable to a variety of diseases, including powdery mildew, root rot, cane blight, and botrytis.
· Caterpillars, cane borers, and scale insects can be serious problems.
· Because raspberries are exuberant about sending out new suckers every year, they can be a headache if they’re in the wrong spot. Make your life easier by planting them in a raised bed or a corner of your yard that’s bounded by a sidewalk or driveway.
· Even if you’re diligent about controlling suckers, you may find raspberries sprouting elsewhere in your yard, courtesy of the seeds deposited by raspberry-eating birds.
· Most cultivars need to be staked, but some have short canes that don’t need support. Likewise, most cultivars have thorns, but some are thornless.
· Raspberry flowers attract butterflies; the fruit attracts birds (and humans).
· ‘Heritage’ (pictured) is an everbearing raspberry with 4- to 5-foot canes that don’t require staking.
· ‘Improved Titan’ is a summerbearing variety with large fruits.
· ‘Canby Red’ has thornless canes.
All in the family
· Other edible Rubus species include R. occidentalis, or black raspberry; R. odoratus, or thimbleberry (also called flowering raspberry); and R. fruticosus, or blackberry (also called brambles).
· Many of our favorite fruit trees belong to Rosaceae (the rose family), including apple, pear, peach, plum, apricot, cherry, and nectarine trees.
(Photo of Rubus idaeus ‘Heritage’ courtesy of Missouri Botanical Garden’s Kemper Center for Home Gardening)