By Russ Cohen

If you’ve done any foraging at all, it is likely you’ve been berry picking. For many, it is among the most anticipated and enjoyable activities of summer. Wisconsin-based wild edibles expert Sam Thayer says in the Eastern U.S., the black raspberry (Ru­bus occidentalis) is the most popular wild berry for picking, although the berry is widely distributed across the Midwest as well. A similar species, whitebark raspberry (Rubus leucoder­mis) occurs on the West Coast.

“Millions of people head to parks, backyards, fencelines and rural road­sides every June or July to fill pails with this beloved fruit,” Thayer says. “Black caps are mild in flavor, sweet­er than a blackberry, less sour than a raspberry – and, in many people’s estimation, have a perfect balance of flavor.”

Black raspberries and other members of the Rubus genus are colloquially referred to as brambles. Black raspberries can easily be dis­tinguished from blackberries due to their hollow center, whereas the core of a blackberry remains embedded in the fruit when you pick it. Black rasp­berries also tend to ripen 3-4 weeks earlier. While raspberries and black­berries are readily available in gro­cery stores, even year-round, black raspberries rarely are. The best way to enjoy this berry’s flavor is to pick them yourself: from wild patches or from plants established in your yard.

How to find wild black raspberry patches
Rubus occidentalis likes to grow in human-disturbed or maintained hab­itats, such as along the sunny edges of fields or meadows. While these are great places to look for ripe berries from mid-June to mid-July, that is not the only time to keep an eye out for black raspberry plants. Fully ripe black raspberry (Rubus occi­dentalis) fruits are dark purple and soft.

One of the best times to discov­er wild patches of black raspberries is in the winter, when their arching stems take on a distinctively purplish color. For successful foraging, devote a notebook to write down the loca­tion of edible plants whenever you encounter them, and then return to that spot when they are in season.

Plant appearance
The individual canes of Rubus occi­dentalis live for two years: they are round, smooth and sparsely armed with sharp prickles that have wide bases and slightly downward-point­ing tips. They are also coated with a white, waxy covering, easily rubbed off with your fingers. In contrast, blackberry canes are green, grooved, and thornier.

In the first year, black raspberry canes grow quickly to their full 5-to-8-foot length but do not flower, hardening and becoming semi-woody by fall. In the second year, these stems develop short side branches that bear flowers and fruit, after which they die, but remain useful habitat for overwintering insects.

In the wild, patches of black raspberry plants often form dense thickets, and their canes are distinct­ly arched. If the tops of the canes touch the ground, they can root at the tips, thereby forming living loops that can make bushwhacking through a patch a challenge.

Rubus occidentalis‘ leaves are compound and composed of three (sometimes five) toothed leaflets, with silvery-white undersides. Black raspberry flowers are among the least showy of all members of the Rubus genus. Each flower has five smallish white petals and five green sepals that can be twice as long as the petals. Within each flower are many pistils (styles) surrounded by stamens. Pollination occurs when pollen from the stamens is trans­ferred to the pistil, mainly through the activity of bees and other insects, although wind can also play a role.

Harvesting best practices
Know the rules: Get permission before harvesting from someone else’s private property and find out the guidelines for harvesting from public property.
Harvest from uncontaminated places: Don’t harvest plants that may have been chemically treated with pesticides or herbicides. Don’t harvest from within 6 feet of a high-traffic roadway or other areas you believe may have contaminated soils.
Wash fruit thoroughly before use: Rinse all harvested berries to re­move dust, pollutants or possible contamination from animals, even when foraged in seemingly clean areas.
Handle plants gently: Pick berries carefully to avoid breaking canes, stripping entire clusters or trampling surrounding vegetation; sustain­able harvest helps ensure future yields.
Harvest when abundant: For native plants, only harvest when the plant is in abundance in the area or when you can harvest a little from multi­ple, separate areas. That will ensure wildlife continues to have a reliable food source.

Black raspberry fruits are ag­gregate, composed of multiple fused ovaries from one flower. Each berry is composed of numerous fleshy drupelets, with one hard edible seed enclosed in each globule. Black caps, a common nickname for black rasp­berry berries, comes from the fact that when the hemispherical-shaped fruit is picked, its greenish-white core stays on the plant, giving each hollow berry the appearance of a tiny cap.

When and how to pick
Black raspberry fruits typically ripen over a three-week period beginning in mid-June. As berries don’t all ripen at the same time, you can return
to the berry patch every two days during the ripening period to pick fruit that has ripened since your last visit. Despite that black raspberry ripening coincides with hot summer weather, pants and long-sleeved shirts are recommended for avoiding thorns during picking.

Fully ripe black raspberry fruits are very dark purple and soft, and range in size from 3/8-inch to 1/2-inch or more in diameter. The larger and dark­er the berries, the juicier and sweeter they tend to be. However, if berries don’t easily detach from the plant, leave them as they’re not yet ripe.
The best containers for picking black raspberries are ones that attach to your belt or hang from your neck, leaving both hands free. My version is a quart-sized yogurt con­tainer; I punch two holes across from each other, just below the container rim, and then tie on a thick piece of string so that it hangs comfortably from my neck. Be sure the contain-er top fits snugly over the opening to help prevent your harvest from spilling as you extract yourself from the patch.

Fruit storage
After you pick the berries, keep them cool and place them in a cooler in your vehicle. One reason black raspberries are rarely seen in su­permarkets is that they have a short shelf life, even when refrigerated. Thus, whatever you don’t eat or cook within that short window should be frozen for later use.
Freeze black raspberries in a single layer on a cookie sheet lined with parchment paper. Once frozen, transfer the berries into clean plastic containers or freezer bags. Frozen black raspberries can last for a year or more.

Uses of fruit
Many people-assert that the best use of berries you pick yourself is to eat them immediately. But black raspberries can be used in a simi-lar fashion to other members of the Rubus genus: filling for pies or other baked goods, drinks, purees and syr­ups, salad dressings, and jams. Black raspberry fruits are a bit on the seedy side, however, so I use a fine-meshed sieve to remove about two-thirds of the seed, and leave the rest in what­ever I am making.

Black raspberry ice cream, with or without chocolate chips, is among the most popular flavors in New En­gland. In Vermont, you can get a soft­serve black raspberry “creemee” plain or twisted half+ half with maple.

Nutritional/medicinal value
While enjoying the berries straight from the patch or in something you’ve made is enough motivation to go foraging for them, Rubus occiden­talis fruits also off er nutritional and health benefits. In addition to vitamin C and fiber, black raspberries are rich in anthocyanins, which act as antiox­idants, offering potential benefits for cardiovascular system health, inflam­mation reduction, and for managing metabolic syndrome. They also con­tain significant levels of ellagic acid, a polyphenol that is showing some potential for cancer treatment and prevention.

What else to eat on a black raspber­ry plant beside the fruit
As with other Rubus species, tea made from black raspberry leaves is pleasant and may also have some medicinal benefits. It can be drunk hot or iced, on its own or mixed with other ingredients such as a few berries. To further improve the flavor, bruise the leaves by first squeezing them under a rolling pin before thor­oughly drying.

As with other Rubus species, young tender shoots of the first-year canes can be peeled and eaten as a vegetable. The peeled shoot should be green and bend easily; if it is white and/or a pith has formed, it is too far gone for eating. Lastly, the whit­ish, waxy bloom on the canes is a source of wild yeast. At any time of year, you can snip off a few inches of bloom-covered cane to create a sourdough starter, or to make wine, vinegar or soda.

Ecological value
Rubus occidentalis offers ecological benefits. The flowers are rich in nectar and pollen, attracting over 15 species of native bees that may also snip pieces of black raspberry leaves for nests. It also serves as a larval host for various butterfly and moth species, and its dried stems provide habitat for overwintering bees and other insects. More than 150 species of birds and other wildlife are known to consume black raspberries. While you may dislike this competition for the fruit, you can find solace in knowing that the seed inside the fruit eaten by wildlife will be naturally scarified in their digestive systems, increasing the likelihood that the seeds excreted by those animals will germinate and produce new plants, helping to create new wild berry patches. Rubus occidentalis‘ arching, thorny canes can also grow into dense, impenetrable thickets that provide a safe haven for small mam­mals and birds to escape predators. Bird species like yellow warblers may choose to build their nests there for that reason.

Growing and planting black raspber­ry plants
To establish a black raspberry patch in your own yard, first decide how to obtain plants: from an existing patch, from seed, or purchased from a nurs­ery or other plant supplier.

Rubus occidentalis can easily be propagated by “tip layering.” That is, place the tip of a first-year stem on the surface of bare ground. Weigh the tip down with a rock, pin it down with a U-shaped landscape pin, or bury it several inches deep. Wait for it to grow roots (which could take place in less than a month); then sev­er your “new” rooted plant from its parent stem. An ideal time for doing this is late summer, as the arching primocanes would have reached their full length, and their tips may already be bending down toward the ground.

With permission, you can also dig up some plants from an existing patch and transplant to a new lo­cation. Plants propagated this way would be clones, or identical copies of the mother plant.

Clonal propagation can be tempt­ing, especially if you encounter a mother plant with characteristics you really like, such as large, abundant or particularly tasty fruit. However, propagation by seed is preferable because it supports genetic diversity and supports the species’ resilience to pathogens and climate change. Ideally, collect seed from wild, straight-species plants near where you intend to grow your own plants.

Propagation by seed
Although seed propagation is the preferred method, it is relatively dif­ficult to grow Rubus occidentalis from seed. As its seed coats are hard, some form of scarification is often recom­mended. This can be done manually: scrape the seeds on sandpaper or soak the seed in sulfuric acid, both of which mimic passing through an animal’s digestive tract; or soak the seed in hot water for 24 hours.

Alternatively, you can warm-stratify the seed. First, wash all the fruit pulp off the seed as the fruit may be a germination inhibitor. Then, place the seed in a plastic bag with slightly damp sand, vermiculite or sphagnum moss and store at room temperature for one to two months. Finally, move the bag containing the seed to a refrigerator and store for another 90 days.

In spring, sow the seed at a depth of 1/8 inch, keeping the soil or other growing medium consistently moist. Expect a relatively low rate/pace of germination, though, which could take months or even years after sowing.

Where to plant black raspberries in your yard
For best berry production, plant black raspberries in a spot where the plants will get a good 6+ hours of direct sun­light. The optimum location may be one that offers morning sun combined with some afternoon shade.

While Rubus occidentalis can tolerate gravelly soil, loamy soil with considerable organic matter will like­ly result in better fruit production. Also, while Rubus occidentalis has some drought tolerance, you’ll get better berry production if you don’t let the plants dry out. Give them supplemental water during periods of low to no rainfall, especially in the weeks between flowering and the end of fruiting. Placing wood chips or other mulch around the places where the canes emerge will help with moisture retention.

Rubus occidentalis tends to spread beyond where it has been planted, so choose its planting loca­tion carefully. This spreading typical­ly takes place underground through roots and suckers and through its primocanes touching the ground and rooting at the tip. Thus, plant black raspberries in a spot where you can control them with methods like mowing.

Russ Cohen, of Arlington, Massa­chusetts, has been leading walks and talking on wild edibles for over 50 years. He is a member of the Wild Ones South Shore (MA) Chapter.