The Monthly Wort: Blackthorn (Part 4)

The Monthly Wort


The Monthly Wort will provide readers with detailed descriptions of specifically chosen herbs (aka “wort”, meaning a useful herb), splitting it into 4 categories over the span of the month. Herbal History, Medicinal Uses, Magical Uses and Growing/Harvesting. In order to get the full scope of each plant, stay tuned every week as we delve into spiritual and practical experience of Herbalism.

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This has been one of my favorite Monthly Worts so far, considering just how fantastic Blackthorn is! This blog is going to be explaining how to grow the lovely prunus spinosa at your home and how to harvest its delicious berries. I would say one of the greatest things about growing Blackthorn is not only its amazing floral display and hedging capability, but caring for it is exceptionally easy once it’s established and it requires very little maintenance (especially if you just let it run rampant).

The Blackthorn Fairy by Mary Cicely Barker

The Blackthorn Fairy by Mary Cicely Barker

Blackthorn is a deciduous shrub that can grow to become a tree of twelve feet with black, rough and scaly bark. The heartwood is brown, while the sapwood is a light yellow. As noted in the prior blogs, it has very dense and thorny thickets, which come in handy when bordering cattle pastures and are great for preventing unwanted outsiders from entering. The thorns themselves can be quite dangerous and wounds from them should be treated immediately, lest they go septic. Lore indicates that both Hawthorn and Blackthorn trees harbor faeries, of which should certainly not be bothered, and that if a person is interested in collecting the thorns, they should do it on the sacred Beltane or Samhain holidays, stipulating that the faeries will be away from the tree at that time. For those that aren’t superstitious, collect away!

  The leaves are dark green in the beginning of the year, turning steadily into a yellow in fall and then falling off during winter. The flowers on Blackthorn trees are small, white and delicate. The petals are ovular and clustered in a star shape. They have a musky smell and tend to blossom between March and April, and are usually the first flowers to do so. Because of their early start in correlation with the farming season, Blackthorn is often used as a natural calendar for planting. In Scotland, the blossoms tell when it’s time to sow the barley.

When the slae tree is white as a sheet
Sow your barley, wither it be drey or wet.

A Homey Environment for Blackthorn

Ideally, you’ll want to plant Blackthorn in the fall to boost root development before winter settles in. It prefers sunbathed locations to better produce its fruit, and its tastes in soil can be rather rich, albeit well-draining. Soil with little nutrients and lots of clay is not optimal in growing environments for Blackthorn and it might require a shrub fertilizer for the first 2-3 years, when it can fully establish itself. That being said, it’s also important to water regularly at the beginning, particularly in dry climates. The best hardiness zones for growing it in the U.S. are 4-8.

Growers beware: Blackthorn can be a very invasive species if left unkempt. While I myself would not mind an entire yard made up of this great plant, those who want to use it in more specific manners will have to keep an eye on it. Wait until fall, after the sloes have dropped, to cut it back every 2-3 years. Suckers grow from its base throughout year and would need to be removed if preventing further growth is desired.


Growing Blackthorn from Seed

To break dormancy in Blackthorn seeds, you will want to use a 50/50 ratio of peat-free compost and horticultural sand. The rule of thumb is two or three handfuls of the mixture to one handful of seeds. A pot is recommended to start your tree off, and you will want to line the bottom of the pot with stones, adding sand coverage next. Then, fill the rest with seed/soil mixture. The last layer on this dirt cake is another 2-3 centimeters of – you guessed it – sand.

A very beneficial tactic is to give the seeds four weeks of warmth, around 68° F. You can put the pots in loosely closed plastic bags to create a better greenhouse effect (or put them in a greenhouse), but make sure to water them every few days or when the soil starts to feel dry. You don’t want them drying out! Following the warm period, the seeds can go outside in their uncovered pots in a place that is protected from wildlife. If nothing sprouts that spring, that’s usually an indicator that they are dormant and will have to wait until the next season to sprout. Meanwhile, place them in a shady place outside until the following spring.

If you have successfully germinated your seeds, congratulations! You will only need 10% germination to get those bad boys sowed. On a seedbed, try to get about 5mm between seeds, pressing them firmly into the soil without having to bury them, then cover with about 5-10mm of grit. They should produce from there.

Blackthorn sapling from

Blackthorn sapling from

Growing Blackthorn from an Established Plant

Blackthorn can also be grown from the suckers it produces, which you can find at garden centers or online. They should be planted in the fall and the new bushes should be weeded and mulched in spring to help establish them. As noted, be sure to water them for the first 1-2 seasons while they get all snug in the ground.

Harvesting Blackthorn Sloes

The small, blue-black berries found on Blackthorn are peculiar little gems, mainly in the sense that they are only valuable for a specific period of time. Otherwise known as sloes, they are quite astringent and bitter if not harvested at the correct time, which would be a pity considering just how delicious they are in pies (or gin)! They also make a fantastic red dye.

The main thing to remember about these berries is that they sweeten with frost, much in the way rose hips do. Waiting until the first or second frost has passed is the best time to harvest the sloes, usually about the end of September and on. They will be soft and have slightly wilted skin, and that is when you know they are ready for picking! But you might have to keep an eye on those trees, as the sloes are favored by birds that will eat them before you know it!  

As far as storing the sloes, they will keep a while if dried in a dehydrator or by the sun, but they will go bad in the refrigerator – keep them sealed in the freezer until you want to cook with them.

A perfect example of hedge laying

A perfect example of hedge laying

Hedging and Hedge Laying

If you want to use these as actual hedges around your property, there are some great sources out there directly from across the pond! People of Europe have mastered the art of hedging and, through my research, I’ve come to find that it takes quite a bit of skill! Apparently it isn’t effective to just plant a row of Blackthorn bushes, as that would lead to spacing between plants that can allow cattle or unwelcome neighbors through. As contradictory as it sounds, the process of hedge laying involves cutting the base of the tree almost all of the way through in order to lay it against the next, all the while adding support posts and woven fence lines throughout. It’s really quite a fantastic display of ingenuity. This webpage is a great source for how to get started with hedge laying, the tools of the trade and effective laying styles according to the different county’s traditions.

That’s it then, Folks. I could honestly write a dozen more blogs on Blackthorn, as it’s one of those trees that has such an old history and fascinating role in even modern lifestyles. Alas, we must move on! Keep an eye on The Monthly Wort to see when Blackthorns sister tree, Hawthorn, will make its debut. Until then, stay wild!

Mountain Hedgewitch

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