Unless you have a grandparent who’s immensely fond of horehound lozenges, chances are you haven’t come across this herb too often. You rarely see horehound growing in home gardens and even less often at the market.
Although horehound has been used medicinally for centuries, it’s not as popular as it used to be. But it’s an excellent herb for respiratory, digestive, and immune support. It’s also delicious in many dishes (including candy, of course). And it repels pests.
Read on to learn all you need to know about growing horehound in your herb garden.
What is Horehound?
Marrubium vulgare is a member of the mint (Lamiaceae) family. Horehound can be found growing wild throughout Europe, North Africa, and many parts of Asia, and has been introduced to North and South America, as well as Australia and New Zealand.
Sometimes spelled, hoarhound, the name comes from the fact that it has slightly hairy leaves. It’s used across the world medicinally and to make beer, candies, and as a seasoning.
If you’ve tasted horehound candy before, you’ve probably noticed that it has quite a bitter aftertaste. Well, that bitterness is significant when the plant is raw. It’s sweetened considerably in order to be palatable in candies and lozenges.
In fact, if I add horehound to my tea when I’m feeling poorly, I have to add a ton of honey into it to choke it down.
That’s good news for us because it means that you can use it as a repellent. In fact, horehound makes an excellent natural grasshopper and aphid repellent.
If your area is prone to them, then you might want to sow horehound in amongst your edible crops. Pests will taste their bitterness and mosey on elsewhere for a tastier salad.
How to Plant Horehound
Growing horehound by seed is a bit trickier than other mint family members. This is because the seeds need to be cold stratified. You’ll either need to plant the seeds in the autumn, or cold stratify them in the fridge for a while before sowing in springtime.
You can try to trick the seeds by planting them 1/2-inch deep about a month before the last frost date, but germination rates will likely be lower.
The seeds can take a long time to germinate, and might not even do so in the first year. Truth be told, it took my seeded horehound three years to show up. Since it’s a perennial, it follows the traditional “sleep, creep, leap” pattern.
As a result, try to keep your horehound in a dedicated patch. This way, you won’t overplant it with something else because you’ve assumed that the seeds have failed. Containers also work well and they can help restrict the spread once this plant decides to take off.
I’m a bit lazy in this regard, so I just get horehound seedlings from the local nursery instead. I’ve also taken cuttings from friends’ plants and transplanted them after they’ve been rooted in water.
If you have a friend with plants (or some of your own), you can also layer them. Just bend a stem down onto the soil without breaking it from the plant and remove the leaves from the part that is touching the ground.
Pin the stem down and bury the section on the ground with a little soil. Within a few weeks, that section will have developed roots. Give it a little tug to see if it resists. If it does, cut it away from the parent plant, dig the section up, and plant it where you want it to grow.
Requirements for Growing Horehound
The good news is that horehound will grow pretty much anywhere. It prefers slightly depleted, dry, sandy soil, but will grow just as well in richer loam. Just make sure that the soil is well-draining, as it doesn’t like wet feet.
Amend your soil with well-aged compost, sand, and/or perlite to make sure it gets everything it needs. It can grow in just about any pH level too, so you don’t even need to test.
This plant needs a lot of sun, however, so it’ll need the sunniest patch on your property. Although horehound can thrive in USDA Zones 3 through 10, it does best in the middle Zones. It likes at least six hours of direct sunshine and plenty of heat.
Like most other minty plants, horehound likes to dry out a bit in between waterings. As a result, don’t fret too much about keeping it damp, and don’t plant it alongside water-loving herbs.
Try to keep your drought-tolerant Mediterranean plants grouped together. For example, try growing horehound and oregano in amongst tomatoes and peppers. Similarly, keep your fleshy, watery herbs like parsley and dill around your greens and lettuces.
Water your horehound at the root level so it doesn’t burn or rot from overhead moisture.
Since this is a member of the mint family, it’s going to spread like wildfire. If you don’t want horehound to become invasive, you’ll need to keep it contained. You can either create a barrier around it or keep it confined to a large pot.
I prefer a pot because then I can move it to different sunny locations as needed.
If you keep it in the ground, you’ll need to thin, divide, or remove clumps from the edge of the patch in order to contain the spread.
Having said that, it’s an excellent plant if you have a dry slope that needs some retaining help.
Trim away any flowers as they form if you want to use the young leaves. You can also cut the entire plant down in the fall to encourage bushier growth next spring. Otherwise, no pruning necessary.
In terms of feeding, you can offer it some extra nourishment in a few different ways:
- Add extra well-aged compost to the surrounding soil in springtime
- Feed it with a balanced N-P-K fertilizer halfway through the season
- Offer the plant compost tea every few weeks
Don’t stress feeding too much, however. This is a plant that can survive a long time without feeding.
Potential Issues with Growing Horehound
The good news is that the bitterness in raw horehound makes it absolutely unpalatable to pretty much all predatory herbivores and insects.
In fact, you can use horehound as protective hedging around your herb garden. It’s so bitter that deer, rabbits, and other herb-loving nibblers will give it (and the herbs within) a wide berth.
Caterpillars and other pesky insects hate it too, but many beneficial pollinators love it. If you’re growing horehound, chances are you’ll have some very happy bees, butterflies, and braconid wasps around too.
The only pests you might get are spider mites, which can be handled with neem oil and/or diatomaceous earth.
Horehound is also resistant to most plant diseases. The only one that may affect it during sustained periods of humidity and heat is powdery mildew. If it does make an appearance, cut away the afflicted areas immediately to stop the spread.
Harvesting, Storage, and Use
If you just want to use the leaves medicinally, then harvest the plant just as the first flower buds are starting to form. This will keep most of the helpful constituents in the leaves rather than drawing on them for flower formation.
Let the plants go to flower if you’d like to attract beneficial pollinators. Then let them go to seed if and when you’d like to keep propagating these plants on your land.
My favorite way to harvest horehound is to cut the stems down to about 3 inches. I use clean garden snips to cut them off, then I tie them up and hang them upside-down in my studio. Use your favorite herb-drying method, and allow these plants to dry completely.
Once the leaves crumble well if rubbed between your fingers, you can store them. Transfer them to a clean, dry jar, and keep them out of direct light.
Horehound can be used as a spice so long as you use a light hand. Of course, you can also use it to make beer and candy.
How to Make Horehound Candies
These lozenges are wonderfully soothing when you start to feel a sore throat coming on. They’re also helpful for alleviating mild coughs, as well as belly discomfort from gas.
- 1/4 cup dried horehound leaves
- 1 cup water
- 1 and 1/2 cups honey
What you’ll need:
- A glass or enamel saucepan
- Wooden or metal spoon
- Baking sheet
- Ice water
- Powdered sugar
- Cornstarch or rice flour
Add leaves and water to the saucepan and heat the water to medium-high heat. When it starts to boil, reduce it to a simmer for about five minutes. Cover, remove from heat and allow it to steep for 15 to 20 min.
Line your strainer with cheesecloth and strain this liquid into a clean bowl. Make sure to squeeze the cloth to get all the liquid out, then discard or compost the leaves.
Prep the baking sheet for the lozenges next. Mix equal parts cornstarch or sweet rice flour with powdered sugar, and spread that over the baking sheet, about 1/3-inches thick. Then use a thimble or the back of a dessert spoon to create hollows all over it.
This is the easiest way to make a mold for your lozenges. Of course, you can also use an actual candy mold and skip this step.
Next, add the liquid back into the pot. Then add the honey, stir to combine, and heat this mixture until it comes to a boil. Reduce the heat slightly and let it boil down until it thickens considerably.
You can test to see whether it’s the right consistency by adding a few drops of it to a bowl of ice water. If it hardens well, it’s done. In contrast, if it’s still sticky (like a taffy candy), you need to reduce it more.
Use a spoon or a small ladle to pour the mixture into each depression. Let them all cool thoroughly so they harden well. Then sprinkle some more of the cornstarch mixture over them so they don’t stick together.
Wrap these individually in waxed paper, if desired, to keep them from mooshing together in storage. Then transfer them to a Mason jar with a lid. Store at room temperature out of direct light, or in the fridge.
Just like all herbal medicines, horehound has a slew of contraindications and cautions. For example, this herb can be an abortifacient or emmenagogue. As a result, it shouldn’t be taken during pregnancy, or by those who have endometriosis with heavy bleeding. Similarly, its blood sugar-lowering effects can interfere with medications that moderate diabetes.
Do thorough research and consult with your healthcare practitioner before taking any kind of herbal medicine. When in doubt, speak to a naturopathic doctor or clinical herbalist for guidance as to whether this herb is right for you or not.