There are so many amazing species in the Rubus genus, but one of the most culturally relevant in my region is the thimbleberry.

Some of you have probably heard of this unique fruit before as an icon of the Northwoods subregion of the Midwest (upper Wisconsin and the Upper Peninsula of Michigan) and know how expensive the jam can be.

Let’s take a look:

Scientific Name: Rubus parviflorus (It’s also important to note that R. ordatus is also called “thimbleberry” but is not the same thing and doesn’t have the same flavor punch).

Preferred Habitat: Thimbleberries grow in gravely and somewhat rocky soil. I typically see them in the understory of forest edges as opposed to clearings, and they seem to grow naturally in dappled shade. That said, I have seen examples of them growing in full sun and in denser soils as well.

Edible Parts: Fruit, leaves, flowers, and roots (all except the fruit are pretty strictly used medicinally).

Distribution: There are two main populations of thimbleberry that are actually distinct; one primarily surrounding Lake Superior in upper Midwest region, and one in the Pacific Coast/Rocky Mountains.

Harvest Season: Late summer (usually Mid-August in the Midwest population)

Key Identifiers: The plant looks like other brambles, but the main feature of thimbleberries are the larger maple-shaped leaves. The flowers in the spring are also much larger than a raspberry and are white in color. Another interesting feature is the naturally thornless canes and the wide, bowl-shaped fruit (flatter and rounder than red raspberries).

Toxic Look-Alikes: As far as I know there are no toxic plants that look like thimbleberry. The fruit does look similar to red raspberries, but both are edible and delicious.

Nutrition:

Thimbleberry has similar properties to raspberry leaf when it comes to herbal remedies:

Thimbleberries can be used pretty much any way you’d use raspberries; in jams, pies, baked goods, oxymels, tinctures, cordials, syrups, cocktails, eaten fresh, and dehydrated into powders.

The roots can also be used to make a tonic, and the leaves can be used for poultices and balms.

These fruits are even more fragile than raspberries so they do not keep long! In my admittedly limited experience, they seem to dry out more than mold like raspberries are prone to.

The taste is often described as “highly concentrated raspberry” flavor, however I don’t think that’s quite accurate. The flavor is much more nuanced and alive than that. I personally think they taste more like if raspberries were citrusy and “brighter”.

It’s really a unique flavor that is best understood by tasting!

The plants have naturally thornless stems that grow to 2-4ft tall (sometimes up to 8 on older plants!)

Like many other Rubus species, thimbleberries also grow from root suckers, although they are much slower to spread. This means that when you see a patch of thimbleberries you are often looking at just a few plants with multiple stems.

Thimbleberries have fairly small yields compared to most other cane fruits, but I believe this is potentially due to two things: Lack of pollination, or lack of sunlight.

If there were more genetically distinct thimbleberry plants in each patch, I believe they’d produce better crops. Sunlight may be an issue, but it’s hard to say when they grow naturally in the shade.

The canes produce flowers in the spring (pictured above) and tend to produce ripe berries in mid-August (I was almost too late to find ripe berries, but I just barely made it!) The timing can be really iffy.

They seem to suffer from inconsistent fruit yields due to environmental stresses like late frosts, intense winters, too much summer heat etc. Some years might be a good harvest; others are very sparse. This is partially why they are so expensive.

I have tried transplanting them before with no success although that could easily have been the time of year I tried. They can be bought as small plugs and transplanted when dormant, and this I have succeeded with so far (this is almost the 2-year mark for my plants.)

Thimbleberries will grow from seed, and I would generally encourage it since they need the genetic diversity, however make sure you are treating the seed how it would naturally grow. In this case, that means scarification (abrasion to the seeds), and stratification (exposure to cold temps for a few months at least.

The huge maple-like leaves are pretty easy to spot and identify. Once you have seen one plant, it is pretty easy to find more!

One important note; “thimbleberry” is a name given to a couple different Rubus species including black raspberries, and purple flowering raspberry.

If you ever see “thimbleberry” for sale and it shows a pink-purple flower, then you almost certainly are seeing Rubus ordatus and not true thimbleberry.

These are still both edible of course, you just won’t get the flavor you’re looking for in a real thimbleberry.

There are two main populations of thimbleberry in the U.S.; the western population that covers the Rocky Mountains and the coast (I like to refer to this as the “Cascadia” population) and the population in the upper portions of Michigan, Wisconsin, and surrounding areas. (Aka the “Northwoods” population).

Recent findings have shown that at one point in ancient history, these two populations were actually connected as one massive collective, but glacial activity separated the two.

After adapting separately from each other for so long, it is now possible to tell which of the two populations a plant is from based on its genetics.

I find it interesting that while thimbleberries grow in several western states. They seem to hold a particularly strong place in modern Keewenaw culture in the form of roadside stands that are all selling thimbleberry jam, the thimbleberry festival which is a series of thimbleberry themed farmer’s markets, and many baked goods and local restaurants featuring the fruit. (I had a thimbleberry cocktail, ice cream, and cake while I was visiting up that way. All were delicious.)

I think these are valuable for the agrarian/permaculture enthusiast for a few reasons:

Thimbles also are not something you’d ever see in the store as-it-is since the fruits are almost exclusively foraged and far too soft to transport.

Unfortunately, there are no cultivars of thimbleberry circulating on the market that I can find.

However, this is a great opportunity to domesticate a very wild species that is otherwise not commercially viable. (You could potentially be rich if you managed to domesticate them!)

Here is a reputable place to buy them if you don’t have any nearby:

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