When it comes to foraging, nothing says “end of summer” like wild plums. During that late August/early September time with cool mornings and moderately warm afternoons, I know without looking that American and Canada plums are ripe.
Prunus, spp.
Most people don’t know it, but Minnesota is home to two species of wild plums.
American plum (Prunus americana) is by far more common. It prefers upland locations and spreads vegetatively, forming dense thickets. According to reputable sources, it can be found all over the state, but is definitely more common around farmland and hardwood forest openings.
The other of our plums is Canada plum (Prunus nigra). It is less common, and more fond of shaded surroundings and higher soil moisture. It is more likely to be encountered the farther north you go (you know, toward Canada).
Telling the two apart is not always easy; it can be more art than science. Still, putting together enough clues should help one make a confident diagnosis.
First, consider the leaf shape. P. nigra (generally) have rounder leaves, while P. americana’s are more ovate, sometimes decidedly elongated/pointed. Also, americana leaves have a more prominent sawtooth margin.
Second, consider the location and each specie’s general preferences. Canada=shadier, wetter, northern. American=sunny, drier, southern and western.
Last, the Minnesota Wildflowers website points out that Canada plum has tiny glands on the leaf stalk, whereas American plum may have glands on the leaf blade near the stalk. Believe me, it can be a struggle to find enough leaves or stems with glands to be certain of their location. However, sometimes it’s a slam dunk.
The Harvest
The window for a plum harvest can vary from year to year, like many other fruits. This year was a tough one, and I believe that was mainly because of the drought. Plums were generally hard to come by. They were often on the small end, and they ripened a bit early, too. The plums that were most ripe on August 19th, for instance, were small and on bushes with yellow leaves (top photo).
In general, I expect American plums to be ripe around the Twin Cities area to be in their prime in the last week of August through the first week of September. That’s also true for Canada plums I’ve picked in the north central part of the state. But as I said, this year was early. If you don’t want to risk missing out, I’d recommend keeping tabs on your best plum thickets from mid-August onward.
Wild plums can be tricky to time just right. Picked a little early, they’ll be mealy and less sweet. Picked too late, they’ll definitely seem overripe. When they’re just right, there’s nothing better. Problem is, it sometimes all plays out in a few days.
In the last couple years I’ve experimented with picking them on the early side and letting them ripen on the counter at home. It works very well if you keep daily tabs on their progress. The trick is to pick them as they get close to their final, purplish stage. Yellow is way too early. Timed right, ripening takes only a couple days. When they feel nice and soft, they’re probably there; it wouldn’t hurt to taste one or two. They should be juicy and sweet. I recommend keeping them in a closed plastic container to keep the fruit flies away.
Tasty, tasty plums
Plum jam is a great way to use them if you don’t eat them all fresh. A couple years ago we made a batch of jam for the first time. It was….okay. This year we tried using plum pulp with pin cherry juice, and the result was better. The ratio was about 3 parts plum to 1 part cherry juice. The plum texture was present, but cherry flavor came through nicely.
I’ll continue experimenting similarly in the future, because I believe that like juneberries, plums make a good main ingredient for mixed fruit jam. I suspect it could be a good use for leftover amounts of chokecherry juice, for instance. Maybe I’ll incorporate some apple from our tree somehow.
What is your experience making plum jam? Any suggestions or crazy ideas you’d like to share? Leave a comment below!
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If you’re interested in learning about more foraged foods, please visit the What to Forage page.