Raspberries take center stage this month, both on the blog and in many of our gardens. Growing raspberries is one of my favorite parts of summer. July is the month these little jewels shine the brightest in my garden, and since they’re one of the yummiest harvests I’m bringing inside these days, I wanted to explore the plant in-depth. So let’s jump into the wonderful world of raspberries!
Summers Are For Berry-Picking
Maybe you have an experience similar to mine: As a kid, each summer I’d venture into the thorny canes, eagerly plucking those bright red, thimble-shaped berries that left my hands stained and my heart brimming with delight. I’d emerge from the thicket with scratched-up arms and hands, a shirt full of berries, and happily go about placing a juicy, red berry atop each of my fingers and thumbs!
Decades later when I started a garden of my own, growing raspberries was a priority. Last summer, we planted several varieties, and this year, we’re already harvesting a cup or two every other day. More on our experience with raspberries later on in the article, but first let’s lay out some raspberry fundamentals.
Raspberry
Botanical Name: Rubus spp.
Family: Rosaceae (rose family)
USDA Hardiness Zone: 3-9 (varies by species and cultivar)
Bloom Time: Summer for summer bearing varieties, and summer and fall for everbearing varieties.
Ripening Time: 10-12 weeks before last frost date
Pollination Requirement: typically self-pollinating, but having multiple plants or varieties can improve fruit set and yield.
Raspberry Basics
Raspberry is in the Rosaceae (rose) family and the genus Rubus, along with blackberry, thimbleberry, salmonberry, boysenberry, and dewberry. I like to think of raspberry as the ruby of the garden because of its genus Rubus, along with the bright red color of its delectable fruits.
Raspberries grow as thicket-forming canes that can reach a height of three to six feet and spread indefinitely through runners.Like other Rubus species, raspberries are fast-growing plants, making them excellent perennials to start now for quick success and to fill in your garden. You’ll be harvesting berries the following year if not the same year you plant them.
Raspberry plants and other Rubus species produce small, bumpy fruits that, while commonly referred to as berries, are actually aggregate fruits composed of many small drupelets, each containing its own seed, giving these fruits their bumpy appearance. The fruits come in a variety of colors, including red, yellow, black, and purple, depending on variety, and are considered a superfood due to their high antioxidant content and beneficial health properties.
Raspberry Ecosystem Functions
In their native habitat, raspberries play important roles in supporting and enhancing their ecosystem. Here are some of the key ecosystem functions provided by raspberry plants:
Attract Pollinators
Raspberries produce beautiful flowers that act as irresistible magnets for bees, butterflies, and other pollinators. These diligent visitors help in the pollination process, ensuring the reproduction of not only raspberries but also other nearby plants in your garden.
Generalist Nectary
Raspberry flowers provide a valuable source of nectar for a variety of insects. By attracting a diverse range of insect species, raspberries contribute to the overall health and biodiversity of their ecosystem.
Food and shelter for birds and other vertebrates
Raspberry plants, with their thicket-forming growth habit, offer a safe haven and a source of nourishment for birds and other vertebrates. The dense foliage provides cover, while the berries provide a nutritious food source.
Raspberry Uses
Most people grow raspberries primarily for their delicious and nutritious fruits, but they also offer uses beyond their food value. Here are some raspberry uses:
Edible Fruit
Raspberries are a widely enjoyed fruit but they’re also incredibly nutritious. They’re considered a superfood as they are a good source of antioxidants, vitamin C, and fiber. They have a low glycemic index, making them good fruits for individuals needing to manage their blood sugar levels.
Medicinal uses
Raspberry leaf tea is used in traditional herbal medicine to support the female reproductive system and prepare for labor. It is typically consumed late in pregnancy but always consult with a healthcare professional first.
Natural Dyes
Raspberries can be used to create natural dyes in shades of red and pink for fabric or other materials. This offers a sustainable and eco-friendly option for those interested in natural dyeing.
Raspberry Varieties
Over 200 species of raspberry exist, but in this article, I’m focusing on cultivated raspberry species that you’re likely to find at your local nursery if you live in North America or Europe. Different countries may have other raspberry species that are either native or cultivars better suited to their climates. For example, Australia has several raspberry species such as Rubus parvifolius that tolerate the warmer Mediterranean and even subtropical climates of the country.
Raspberry Species
- Red raspberry (Rubus idaeus) is native to Europe (R. idaeus var. idaeus) or North America (R. idaeus var. strigosus), and is the most common and well-known raspberry species. Most red and yellow raspberry cultivars are Rubus idaeus species or hybrids of it.
- Black raspberries (Rubus occidentalis), also known as black cap raspberries, are native to Eastern North America. They bear larger, dark purplish-black fruits with a sweet tangy flavor reminiscent of blackberries. Cultivated black raspberry varieties typically belong to the Rubus occidentalis species, while purple raspberries are usually hybrids of R. occidentalis and R. idaeus.
Summer Bearing vs. Fall Bearing Raspberries
Raspberries can be classified as either summer-bearing or fall-bearing.
- Summer-bearing raspberry varieties produce fruit in early to mid-summer on canes that grew the previous year.
- Fall-bearing raspberry varieties, also known as everbearing or primocane-bearing raspberries, provide an initial harvest in early to mid-summer on the previous season’s growth, followed by a second crop in fall on the current season’s growth.
Common Raspberry Cultivars
There is a diverse range of raspberry cultivars available, each with its own unique qualities. Some popular cultivars include:
- ‘Heritage‘: A summer-bearing raspberry variety with large, sweet, and juicy red berries. It is known for its excellent flavor and productivity.
- ‘Caroline‘: A fall-bearing variety that produces large, firm, and flavorful red berries. It is prized for its abundant harvest and disease resistance.
- ‘Fallgold‘: A fall-bearing variety with bright yellow berries. It offers a sweet and mild flavor, perfect for fresh eating or culinary purposes.
As I mentioned earlier, we planted raspberries last summer and this year we’re already getting a sizeable harvest. We tried four different varieties, which I’ll describe below. Although we prefer some of the varieties over others, I expect all of them to improve in subsequent years as the plants mature.
- ‘Prelude’: Our favorite so far, a red summer-bearing variety that has tall, vigorous growth and produces a sweet-tart, tender, and prolific berry. It is our first raspberry variety to ripen and does so in June. It may also have a smaller second crop in the fall.
- ‘Nova’: Another red summer-bearing variety, ‘Nova’ has a firmer textured berry that ripens on top first, so you have to look underneath to check for full ripeness. Some of the berries seem to dry out before fully ripening, but this could be due to our current heatwave.
- ‘Double Glow’: This fall-bearing yellow variety is a close runner-up to ‘Prelude’. Its berry is smaller and sweeter, and so far its yield has been smaller too, but since it’s a fall-bearing variety, it’ll provide a larger second harvest in fall.
- ‘Anne’: is a light yellow fall-bearing variety. It’s the largest of the four we planted, and so far isn’t nearly as productive as the others but its berries are two to three times the size. I also suspect that of the two plants I started with, only one was actually ‘Anne,’ and the other was an unknown red variety that got mixed in at the nursery. This could partially explain the lower productivity.
Growing Raspberries
Growing Raspberries in Rows or Patches
Probably the most recommended way to grow raspberries is in rows with trellis support. Two-foot-wide rows with three-foot pathways work well.
Alternatively, you can grow raspberries in a patch, which is a three to five-foot diameter circle. Some varieties may need support around the perimeter of the patch, while others can grow without it.
Trellising Raspberries With T-posts and Wire
To trellis raspberries in rows, you can use T-posts placed at each of the four corners. String a galvanized heavy gauge wire (10-12 gauge is recommended) along the length of the row, and if desired, on the short ends as well. Create three levels of wire at 18 inches, 36 inches, and 54 inches from the ground. As the canes grow, tuck them inside the wire to provide support. Any canes that pop up outside the trellis should be carefully dug up and transplanted, given away, or composted.
Rhizome Barriers to Control Raspberry Runners
Rhizome barriers, also known as root barriers, can be a useful tool for managing the spreading nature of raspberries. These barriers are physical barriers that can be installed underground to limit the horizontal growth of raspberry rhizomes, helping to contain them within a designated area and prevent unwanted spreading into other parts of the garden or neighbors’ yards.
Pruning Different Types of Raspberry Canes
Raspberries have two types of stems: primocanes (first year) and floricanes (second year). Primocanes are the first-year canes that grow from the base, while floricanes are the second-year canes that bear fruit.
For summer-bearing raspberries, prune the spent floricanes after fruiting, usually sometime in late July or August, leaving the new primocanes for the following year’s crop.
Fall-bearing varieties can be pruned differently depending on the desired harvest time. You can choose to cut all canes to the ground in early spring for a single fall crop or prune only the spent canes after the fall harvest for a two-crop system.
Raspberry Pests and Natural Management:
Creating a diverse garden ecosystem can help promote healthy raspberry plants and minimize pest and disease issues. Companion plants like marigolds, calendula, and nasturtiums can repel pests, while attracting beneficial plants like yarrow, dill, and fennel can invite helpful insects like ladybugs and lacewings that prey on pests.
Here are a few common raspberry pests and how to handle them.
- Fruit-eating insects such as sap beetles and yellowjackets can be deterred by harvesting berries often, preventing overripe fruit from attracting them.
- Japanese beetles can be manually picked off in the evening or early morning when they’re less active.
- Watch out for cane borers, as they can damage the canes by burrowing into them. To control their spread, trim affected canes in winter, cutting five inches below the galls, and dispose of or burn the canes to destroy the larvae.
- Spotted wing Drosophila can be managed by regularly picking raspberries and separating any affected fruit – dispose of infested fruit in a way that won’t reinfest the crop.
To keep your raspberry plants healthy, manage cane diseases with cultural practices such as pruning for better airflow and using drip irrigation to keep leaves dry. By incorporating these natural management techniques, you can protect your raspberry plants and ensure a bountiful harvest. For more information, check out the University of Minnesota Extension Resource: Pest Management for the Home Raspberry Patch.
Harvest & Preservation of Raspberries
Harvesting raspberries at the peak of ripeness ensures the best flavor and texture. Here are some tips for harvesting and preserving your raspberries:
When and How to Harvest
Harvest raspberries when they are fully colored and easily detach from the receptacle (the central core) with a gentle tug. If there is any resistance, leave the berry to ripen another day or two. Hold the berries gently without squishing or crushing them. Ripe berries are delicate, so handle them with care. During peak production, harvest raspberries at least every other day to make sure none get overripe or fall to the ground.
Ways to Enjoy Fresh Raspberries
A favorite way to enjoy raspberries is fresh off the cane. Eat them as you pick or bring them inside and refrigerate, washing only just before use. If you have a large harvest, you may wish to try different ways of using them fresh. Put them in desserts such as pies, tarts, crumbles, and crisps, as a topping for ice cream or yogurt, or decoration on a cake. Or add raspberries to salads, smoothies, or your breakfast oatmeal.
Raspberry Preservation Methods
If you can’t consume your whole harvest fresh, or wish to save some for later, there are several ways to preserve them. Freeze raspberries by placing them in a single layer on a parchment paper-lined baking sheet and putting it flat in the freezer until they’re firm. Then transfer them to airtight containers or freezer bags and return them to the freezer. Freezing is my preferred method to preserve raspberries. But, you can also use raspberries to make jams, jellies, and syrups.
Cautions for Growing Raspberries
As with most plants, there are a few cautions to keep in mind when growing raspberries.
Thorns: Raspberry plants have thorny canes, so handle them with care to avoid pricks and scratches. Wearing long sleeves can provide protection when harvesting the fruits. When pruning, wear long sleeves, gloves, and eye protection.
Spreading Habit: Raspberries have a thicket-forming growth habit and spread through underground runners. It’s important to manage their growth by containing them within desired areas. Regular pruning, installing a rhizome barrier, removing any canes that stray outside the designated space, and maintaining proper spacing can help control their spreading habit.
Medicinal Uses: If you plan on using raspberry medicinally, as with any natural product, it’s important to exercise caution and moderation. Consult with a healthcare professional or herbal specialist before using raspberry leaves or roots medicinally. Particularly, pregnant individuals should seek guidance from healthcare providers before consuming raspberry leaf tea or using raspberry medicinally during pregnancy.
Conclusion
Raspberries are not only a delicious and versatile fruit but also a valuable addition to the garden. By attracting pollinators and providing food and shelter for birds and insects, raspberries contribute to a thriving garden ecosystem. Raspberry fruits, rich in antioxidants, vitamin C, and fiber, offer numerous health benefits. From fresh consumption to various culinary uses and preservation methods, raspberries can be enjoyed in a variety of ways throughout the year. However, it’s important to be mindful of their thorny canes and their spreading habit, requiring proper management and containment. By understanding the different varieties, implementing trellising and pruning techniques, and considering natural pest management methods, you can cultivate healthy and abundant raspberry plants. So, why not embark on your raspberry-growing journey and savor the joys of homegrown raspberries? Happy gardening!
