GROWING INCENSE TREES

For several years now I have been building up a collection of Boswellia (frankincense) and Commiphora (myrrh) trees, all of which will have to be content to grow more or less as bonsai. They seem easy to grow in pots, but are leafless during the winter, and during the summer, too, if I don’t water them regularly. In the spring, after their winter dormant period, all of these trees start to leaf out, so at that time I try to give them plenty of water to facilitate the process. One day early last spring I noticed that the Boswellia neglecta had a big drop of resin exuding from a place where it had been trimmed months previously. I can only conclude that when the plants break dormancy their sap starts flowing the way maple sap does, and that it leaks out of any cut area. After producing sap, the little tree put out some nice, green, frond-like leaves, lost them during the winter, and has now grown more leaves. Through all this, the resin drop has kept hanging on. 

Early this spring the little Boswellia carteri tree lost its leaves, at which time some tiny drops of resin oozed out along the leaf stems. I collected these drops and tasted them, which was the best and easiest way to evaluate them. They tasted and smelled exactly like frankincense oil. This is already way more that I had hoped for when I bought the tree as a curiosity.

I also have a 3-foot (1 meter) tall Commiphora tenuipetiolata tree that had started to branch out from the side of the trunk. One of my assistants bumped against it last fall and broke the branch partially off. A week or so later I noticed a blob of resin accumulation around the break. This tree is actually large enough to produce some significant resin, so that made me think that maybe I'll be able to harvest a little incense from my plants after all! There should at least be a few small drops that I can burn. I’m looking forward to having some frankincense, but it will be especially interesting to see what the resin of all of the different Commiphora species smells like. 

[All photos are mine]

MATERIALS: FRANKINCENSE AND A GIVEAWAY

From elemi, the obvious place to go is frankincense. I wrote a post on frankincense back in 2010 when I started this blog, but it wouldn’t hurt to do an update. Frankincense, also known as olibanum, is another resin that comes from trees in the family Buseraceae, in this case Boswellia. The resins used in incense and perfumery come from several different species, each with its own aroma profile, and each species yielding a slightly different scent depending on origin. Boswellia is native throughout arid landscapes in India, North Africa, and the Arabian Gulf regions. 

The trees themselves are, to me, very attractive, typically with gnarled trunks covered with smooth bark that peels as the tree grows, and sparse, lacy leaves. Boswellia trees are deciduous, losing their leaves during times of stress, typically during the dry season. Resin is obtained by making shallow cuts in the bark of the tree and harvesting the dried resin. Oil is obtained by distillation, although the raw resin can also be tinctured.

I am growing seedlings of several different Boswellia species: dioscoridis, neglecta, and carteri. Given my propensity to under-water or just forget to water, they seem to do well in my hands. The carteri is the largest one, and has kept its leaves this summer. The other two have lost theirs because they’re small and in a very hot, dry location. They’ve done this before, so I know they’ll perk up and grow when summer is over.

Frankincense is one of those materials that I’m worried about. Although it’s listed as “not threatened”, the trees can only produce so much, and it’s likely that their habitat is diminishing due to the same sort of reckless human activities that are destroying nature everywhere. Boswellia seedlings are eaten by domestic animals, trees are burned by fire, they are cut down to clear land or to use for firewood or lumber and, of course, over-harvesting of resin weakens trees. I keep my stash of resin and oil against the day when these things may no longer be available, or when the price has risen because supply cannot keep up with demand.

Boswellia is a traditional Ayurvedic medicine reputed to have strong anti-inflammatory properties as well as anti-microbial, anti-fungal and insect-repellant properties, yet another example of trees producing compounds that help keep them healthy and infection-free.

The species that produces the “lightest” and greenest oil is B serrata, which grows in India. This oil is closer to the citrusy-green scent of elemi than the others, and very much in the direction of pine needles. The primary constituent is alpha-pinene (over 70%!), with small amounts of limonene, verbenol, pinocarveol, myrcene, borneol, para-cymene, and other trace molecules. I used Boswellia serrata oil in Gujarat along with B carteri to provide a light incense note to go with the smoke element of the scent.

Boswellia carteri is the most common species used for the production of resin and oil. The scent is very different from that of B serrata, much richer and more resinous. Alpha pinene makes up less than half of B carteri oil, the main constituents being diterpenes whose long chemical names you really don’t want to see, although if you’re really curious you can view them here, and octyl actetate, which has a distinctive fruity smell. I have used Boswellia carteri oil in a number of my perfumes, most notably the Devil Scent series, where it was used to give a vague impression of burning incense. I also use it, along with natural sandalwood oil, in my Body Balm.

This is getting long, so the post on the different types of Boswellia will probably be continued next week.

Leave a comment about what type of frankincense you like, or what frankincense-containing perfume(s) you like and be entered in a drawing to win a 5-ml travel spray of the Devil Scent of your choice plus some extras.

[All images are from Wikimedia]  

GROWING FRANKINCENSE TREES

As a plant and perfume enthusiast, what could be more perfect than growing a selection of plants traditionally used in perfumery? I’m not talking about roses and orange blossoms, I’m talking about more exotic things like frankincense and myrrh trees.

Recently I’ve gotten into growing cacti and succulents, thanks to a cactus that bloomed and produced 91 babies. When I saw baby frankincense trees for sale, I knew I had to have one. My first desert tree acquisition was a Boswellia carteri, the species most commonly used to make resin and oil [photo on right]. When it arrived, it looked like a bare-root dead stick with no leaves. I planted it, watered it, and within a few weeks some tiny, frilly leaves had begun to sprout. It’s now doing quite well in a hot spot high in the grow space. These trees go dormant when conditions are non-optimal, so I expect it will go lose its leaves again in winter.

One thing led to another, and I’m now the proud caretaker of a tiny Boswellia dioscoridis [photo on left] and a Boswellia neglecta, as well as a larger Commiphora wightii. [photo at bottom right, along with a Bursera fagaroides]. The Commiphora arrived just like the B carteri, as a dead-looking stick, and took forever to leaf out. However, it's now growing quite well. I’m on the lookout for an affordable Commiphora myrrha, the main species used to make resin and oil, but will have to be patient until one comes along. 

These all belong to the general class of pachycaul trees, which are fat-trunked trees that store up water for hard times – perfect for my conditions.

Pachycaul trees all seem to do OK in my hands, unlike the patchouli plant that I bought a couple of months ago, which turned out to be a disaster. The patchouli was nice and green when it arrived, but I quickly discovered that it goes through water even faster than a hydroponic basil plant. If not watered every day, it wilted. It also seems to want high humidity, which I simply can’t provide in the summer. I can’t deal with plants like that, so within a couple of weeks it had burned to a crisp despite my best efforts. No more patchouli for me. I will consider the poor patchouli plant a sacrifice to the gods of gardening to facilitate the growing of plants that can go for long periods of time without water like the little Boswellia trees.

I doubt that I’ll ever harvest resin from my frankincense or myrrh trees, but I just like having them around to remind me where the materials I use come from. 

[All photos are mine]

FRANKINCENSE

Frankincense, also known as olibanum, is among the most wonderful of all natural perfume materials. I love it on its own, and as the basis of the “incense” note, but it’s also extremely versatile in combining with all kinds of other scents. Frankincense is the resin of a type of shrubby tree belonging to the genus Boswellia, which grows under harsh desert conditions, mainly on the Arabian Peninsula, in North Africa, and in India. The resin is collected by making cuts in the bark of the trees, allowing the sap to leak out and harden, forming frankincense “tears”. For incense, the tears are burned as is, or powdered and mixed with other things. The powdered resin can also be used to make a tincture. The resin is distilled to produce its essential oil.

Frankincense is probably familiar to some as “church incense”, which traditionally was Boswellia sacra or papyrifera, sometimes mixed with other aromatic substances such as myrrh and spices. There are many different species and varieties of Boswellia, all of which smell a little different, but all of which have a deliciously aromatic resiny scent.

How to describe frankincense? It’s like trying to describe the scent of a rose. It is what it is, and once you smell it there’s no mistaking it. Just as nature provides uncountable variations on the rose theme, there are variations on frankincense. I’ve been sampling a number of different types of Boswellia, and thought it would be interesting to write down some observations about each one.

Boswellia carteri: This comes from Somalia and Ethiopia. It’s the prototypical frankincense scent, rich and complex, with citrusy, resiny notes, the typical spicy, fruity, “incense” heart, and a bit of almost animalic woody scent, the funkiness of which goes away after a little while. B carteri is one of my favorite all-purpose frankincense varieties.

Boswellia sacra: The one that I have comes from the Dhofar Valley in Oman, and is similar to carteri, with all of the fruity, woody, incense-y notes, but a bit sharper, with more wood and spice notes. It’s a wonderful oil that I’m saving for something special.

Boswellia freereana: The one that I have is from Somalia, and has much more of a citrusy, pine-needle scent and less of the deep, woody, incense-y base. It’s sort of a “frankincense lite”. The woody note is more cedar-like than the other types.

Boswellia serrata: From India, it’s similar to freereana in that it’s a somewhat lighter scent. It doesn’t have the pine-needle note, but it is citrusy, with a characteristic sweetish woody scent of its own that’s hard to describe, but is very much like “church incense” with a tiny touch of vanilla.

Boswellia neglecta: From Kenya, this is a fairly heavy hitter, in the same league as sacra and carteri, but with slightly less of the funky-woody note. It’s a wonderful incense scent.

Boswellia papyrifera: I could have sworn I had this one, but all I can find is the resin tears, not the oil. My recollection is that it’s similar to sacra and carteri. I’ll search again and update in due course.

One of the interesting things about frankincense essential oil is that it gets better with age. I have a small amount of generic frankincense essential oil that’s at least 15 years old, and it’s the best I’ve ever smelled. I doubt that any of the oils that I currently have will make it that long, but if they do, they will make some amazing perfumes.