Whether we garden or not, Tu B’Shvat is also an obvious time to reconnect with trees. There are many ways of doing this. We can think about the gifts that we receive from trees, take walks among them, meditate with them, eat and drink their offerings, and learn from and about them. I try to do all of these, and in this article, I shall share some of my thoughts and gleanings. First, I’ll bring you with me on a walk that I took recently in the Acton Arboretum as I was thinking about what to write, and then I’ll move on to discuss plant identification and use, and eventually I’ll hone in on some ways to use a tree from which you can easily and sustainably harvest in the winter.
Recently, my daughter and I went for a walk along a loop trail in the Acton Arboretum. The trail begins in an ex-urban parking lot, then quickly takes its pedestrians into a wooded area, then into marshland, and eventually back to an open area abutting a residential neighborhood. Since I am interested in tree identification, I walked slowly, pausing to contemplate the trees, notice the branching patterns and the fallen leaves, note buds where there were some, observe the textures and varied browns and greys of bark, and sometimes hazard guesses about what species the tree might belong to. This was a risky enterprise; as an arboretum, the place collected trees from all over the world, and so the trees were often not what I expected; many turned out to be guests from Asia or Europe.
This abundance of global trees led me to wax a bit nostalgic for the time when humans actively celebrated such diversity, and when the people responsible for arboreal collections—whether as small as a yard or as large as a multi-acre botanical garden—eagerly sought out saplings from overseas. I wish I could say that the welcome approach to trees extended fully to humans; it did not. Bigotry has always been among us. Nonetheless, this country has not always required visas for humans, nor restricted entry among plants. Today, xenophobia governs our approach to both plants and people. The language of native vs. alien, applied to plants, relates as much to the culture of xenophobia as to concerns about preserving local species. For plants and for humans, we use language selected to alienate, and in both cases, the objections raised against the supposed aliens and the defense offered to the lauded natives are at best too sweeping, at worst, simply bigotry. I’ll give a few plant examples. I am sadly confident that you can think of human examples without my help. To be clear, I am not suggesting that the harm caused by xenophobia toward plants is comparable to the harm caused by xenophobia toward humans; it is not.
One common “alien” plant worth getting to know is the common plantain, Plantago major. This plant grows abundantly on every sidewalk and in parks, yards, and parking lots. It grows non-competitively among numerous other plants, some of them “native,” and others that are “immigrants” like itself. Plantain hitched a ride here with the earliest Europeans, travelling on their shoes, so that they inadvertently planted it as they walked. It’s an extremely useful plant: edible, nutritious, anti-inflammatory, styptic, and strongly astringent. It can stop bleeding and pull out a splinter, even one in smithereens. It can also counter erosion. It often grows in the same environment as dandelion, another useful, non-competitive, “alien” plant.
Jewish tradition teaches us to welcome the stranger, and specifically to love the one who is other or alien: ואהבת לרעך כמוך, v-2ahavt l-re3ekh/a kmokh/a. We need to get better at doing that with humans, and we should extend it to plants as well. We are also commanded to have a single law for the native and non-native. Place of origin is irrelevant; behavior matters. So does the context of the behavior.
So what is the behavioral issue to consider when we’re trying to ensure that our plant companions work well in their environment? Allelopathy.
Allelopathic plants release chemicals to deter or prevent competitor species from growing in their midst. Like so many traits in both humans and plants, this may be useful or harmful, depending on the context. In a landscape where we want diversity, or where endangered species grow, it’s highly problematic. In a garden or a farm where we’re trying to privilege a limited number of species, it’s sometimes useful; in fact, it can be a form of weed control. Wheat, sorghum, sunflowers, and chestnut are all allelopaths; this is not a reason to bar them from farms. At the same time, we shouldn’t plant them near a lady’s slipper, which is endangered.
Both “native” and “alien” species may be allelopaths, and both “native” and “alien” species may be non-allelopathic and non-competitive. The issue is not whether a plant originated on this continent or another, but whether it is allelopathic or not in the specific context of its growth; allelopathy may be beneficial, harmful, or neutral, depending on the specific environment. Sometimes even “alien” allelopathic plants that tend to grow where we may not want them can be useful; Japanese knotweed, for example, is the main source of resveratrol, and is also useful for addressing Lyme disease. We need to allow complexity and nuance into our thinking and speech about both plants and humans, and not simply malign a vast set of either. Once we understand this, perhaps we can go back to celebrating a diversity of plants that includes the “foreign ones,” and stop using language that echoes and supports xenophobia.
As we celebrate plants in their diversity, it’s helpful to learn more about them. For some years now, I’ve been trying to learn to identify more trees, including in the winter. The first question to ask for tree identification is whether the tree is deciduous or an evergreen. The leaves of deciduous trees lose their chlorophyll slowly over the course of the season from spring to fall. The gradual loss picks up speed in fall, so that the leaves ultimately lose the green color that came from their chlorophyll and reveal their true colors just before their tree cuts them off and they drop or fly off.
If the tree is deciduous, the next question is whether the branches are opposite or alternate. If they’re opposite, they emerge in twos from the trunk or larger branches, with each branch in the pair originating in the same place as the other, but on the opposite side of the trunk or main branch. In the image below, you can see that all of the branches and the leaves are opposite:
Next, it’s useful to observe the bark and ask what color it; whether it is smooth or rough; whether it is peeling off, or has already peeled off to some extent, and if so, in whether it peels in strips or patches, and whether it has lenticels. Lenticels are regular marks on the bark that are considered lens-shaped; the tree “breathes,” or exchanges gasses with the atmosphere, through the lenticels, as if they were nostrils. The dash-like lines on the bark of birch trees are lenticels.
If the tree is an evergreen, the first questions about identification will focus on the arrangement and texture of the needles. Evergreens continue to produce chlorophyll all year round, so their needles stay green and continue to provide nourishment for the tree. One of the most common evergreens in our area is the white pine, identifiable by its five-needle bunches. This is also one of our most useful trees, as it is both medicinal and edible.
White pine trees have copious amounts of vitamin C, as well as essential oils that open your chest and help you breathe more deeply; pines are especially good for helping to fend off respiratory ailments. There are many ways to use pine culinarily and medicinally.
If you find buds in the branches of a white pine tree, snack on them raw or toss them into salads. You can snack on the needles as well if you like; I prefer to turn them into pine balsamic vinegar, which tastes similar to commercial balsamic vinegar.
To make pine balsamic vinegar, you’ll need a jar and lots of pine needles (green, not brown). In the winter, I often harvest fallen pine branches. At this time of year, if you take a walk in the Middlesex Fells or whatever other forest is near you, you’ll probably find plenty. You may find some even in a city park, although I would feel more confident harvesting from a place farther from traffic.
For the pine vinegar, you’ll also need apple cider vinegar, and a non-metallic (i.e., non-corroding) lid for the jar. You have two options for how to make it, and it’s fine to combine them. The easier method is to stuff as many pine needles as possible into the jar, pour the apple cider vinegar over the needles, and let the needles infuse for three weeks or longer, shaking the jar whenever you remember to. The slightly more complex method adds the step of cutting the needles, which will give you a somewhat stronger infusion. In either case, after three weeks the vinegar is ready for use. You can decant it at that point, or simply take what you need as you need it while leaving the pine needles in the jar.
There are also a few different ways to make pine tea. You can put needles and branches into a tea ball or infuser, pour on hot water, and let steep (infuse) for fifteen minutes, or you can make a stronger brew by tossing the needles and branches into a pot and simmering (decocting) for up to thirty minutes. The infusion method will give you a very mild, subtly flavored tea, while the decoction will be stronger. You can’t combine the infusion method with the decoction method, but just as with the vinegar, you have a choice between putting in whole needles and branches and cutting them up, and here you can combine methods. The stongest brew would be from cut needles simmered for half an hour.
Don’t throw away any branches! They’re very good in stews and soups. Pine bark, like the needles and buds, contains vitamin C, so the branches impart an acidic taste that perks up the flavor of your dish in much the same way that vinegar and lemon juice do. The bark is edible, so you can gnaw on the twigs as you might on an ear of corn or a bone. Once you’ve gnawed the bark off a pine twig, you’re left with a small wooden stick that resembles a bone. Two years ago I used a tiny, bone-like pine twig for zroa, to substitute for the paschal beet or shank bone at our Passover seders. This was the year when Passover fell shortly after the beginning of lockdown and I was trying to avoid stores as much as possible. The place of pine at a Tu B’Shvat seder is at least as appropriate as at a Passover seder.
Most of what we eat at a Tu B’Shvat seder gets the פרי העץ pri ha-3ets blessing. We tend to think of this blessing as one to say over fruit, but our two blessings for produce use the word “fruit” (pri) metaphorically as well as literally; all vegetables are פרי האדמה pri ha-2adamah “fruit of the ground”—unless they grow on trees. Pine bark is as much “fruit of the tree” as a carrot is “fruit of the earth,” so the פרי העץ pri ha-3ets blessing would be appropriate for pine needles, bark, and buds as well as for less metaphoric fruits. When we make this blessing and eat the pine parts, we can use the tree for contemplation and for nourishment at the same time.
 In this transliteration system, the 2 and 3 represent stops (glottal and pharyngeal respectively), pauses in the sound, similar to that in the middle of uh-oh. I borrow this from the Arabic chat alphabet.