African Blue Basil

One of my favorite herbs sits in my perennial herb bed, and it’s a basil. Yep, a perennial basil. I never even knew such a thing existed until I found my African Blue at a nursery. It flowers almost year-round with pretty purple and lavender buds on long stems, but never bolts and tastes just as lovely as it looks and smells.

African Blue basil (Ocimum kilimandscharicum x basilicum “Dark Opal”) is a sterile hybrid of an East African camphor basil and a standard garden variety called Dark Opal. Propagated only through cuttings, African Blue survived an unusually cold and wet winter outside in my zone 10b (Sunset zone 24). Though its growth slowed for a couple months, it perked right up in spring and thrived into a wild-looking shrub.

Considered a tender perennial, it probably won’t live through frost, but overwinters well if grown in a container indoors. And since it just likes to grow and grow, it benefits from as large a container as you can give it.

New foliage starts out a deep purple but as the leaves mature, they become bright green, retaining only flecks of purple. The herb has a strong, earthy basil flavor with a mellow camphor scent. If rosemary and clove had a basil baby, it would be African Blue.

Since this breed of basil doesn’t go to seed, you can let the flowers bloom all they want, and the plant will still keep going strong for many years. If you want a bushier basil, you can pinch it off and use the edible flower stems as a soup or salad garnish… float them in a glass of iced tea… or sprinkle the buds over roasted potatoes.

Some of my blooms grow over 10 inches tall and I arrange them all over my house in fragrant mini bouquets.

I have to admit that I’m rather spoiled now. I pick fresh basil in my garden year-round. It’s a kitchen gardener’s dream!

African Blue Basil flowers

African Blue Basil flowers

(Photo courtesy of NetPS Plant Finder)

Plant Height: 18 inches

Flower Height: 24 inches

Spread: 18 inches

Sunlight:

Hardiness Zone: (annual)

Edible Qualities

African Blue Basil is an annual herb that is commonly grown for its edible qualities, although it does have ornamental merits as well. The fragrant oval bluish-green leaves with distinctive purple veins which emerge deep purple in spring are usually harvested from early summer to early fall. The leaves have a pleasant taste.

The leaves are most often used in the following ways:

  • Fresh Eating
  • Cooking
  • Seasoning

Planting & Growing

African Blue Basil will grow to be about 18 inches tall at maturity extending to 24 inches tall with the flowers, with a spread of 18 inches. Although it’s not a true annual, this fast-growing plant can be expected to behave as an annual in our climate if left outdoors over the winter, usually needing replacement the following year. As such, gardeners should take into consideration that it will perform differently than it would in its native habitat.

This plant is quite ornamental as well as edible, and is as much at home in a landscape or flower garden as it is in a designated edibles garden. It should only be grown in full sunlight. It prefers to grow in average to moist conditions, and shouldn’t be allowed to dry out. It is not particular as to soil type or pH. It is somewhat tolerant of urban pollution. This particular variety is an interspecific hybrid. It can be propagated by cuttings; however, as a cultivated variety, be aware that it may be subject to certain restrictions or prohibitions on propagation.

African Blue Basil is a good choice for the edible garden, but it is also well-suited for use in outdoor pots and containers. With its upright habit of growth, it is best suited for use as a ‘thriller’ in the ‘spiller-thriller-filler’ container combination; plant it near the center of the pot, surrounded by smaller plants and those that spill over the edges. Note that when growing plants in outdoor containers and baskets, they may require more frequent waterings than they would in the yard or garden.

If you love eating basil all year round and want a beautiful edible plant that will bring the bees to your garden then without a doubt you have to get your hands on this beauty.

This perennial herb (for us warm climate dwellers) is a hybrid of two different species Ocimum kilimandscharicum (camphor basil) and Ocimum basilicum (dark opal). Due to this hybrid status, you can leave the flowers and you don’t have to worry about it going to seed and dying, although giving it a good trim back will make it very lush and bushy.

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Love this African blue basil 😍😍😍

A post shared by Nicki Murray (@loveofdirt) on Aug 10, 2018 at 11:11pm PDT

The leaves start out as a beautiful purple and as the plant gets older the leaves turn green. It has stunning purple flowers which are like bee tractor beams, my plants always have a swarm of bees getting the goodness out of those purple flowers. It also makes a beautiful cut flower for inside if you are so inclined.

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Hello friend 🐝

A post shared by Nicki Murray (@loveofdirt) on Oct 31, 2018 at 5:01pm PDT

The taste

The flavour of the african blue basil I find is earthy and less aniseed like other perennial basils, so I use it as I would a sweet basil. It makes a beautiful pesto, and is also great in bruschetta.

Growing space

If you’re going to grow this one in a pot, pick the biggest one you can get. It can get quite big, my original plant which I harvest from quite regularly has taken over a 1m square garden bed. It did successfully grow in a 20cm pot before moving it to this bed, but you can really tell it let it’s roots spread when it was given the space.

Location

It loves sunshine and good draining soil, so choose a spot that is going to get plenty of it. We have clay soil, and it seems to do well directly in the garden, but I’ve heard of it turning up it’s toes if it’s always got wet feet. So like most things, lots of sunshine and well draining soil.

Care

To keep your plant lovely thick and lush it can deal with a good prune every now and then (and if you love basil that’s easy to do). I honestly don’t give it much in the way of anything else, but making sure your soil is in tip top shape is going to do wonders.

Propagation

Sadly because it’s a hybrid species you can’t save the seeds. It is however one of the easiest herbs I have ever propagated, and I found out by mistake when I cut some of the flowers to put in a vase inside, within a week the cutting had enough roots to directly plant out.

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Kitchen windowsill propagation station

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Have you got an african blue basil? What’s your favourite basil?

African Blue Basil in bloom, with pollinator-friendly flowers.

Most basil plants we try to discourage from blooming because we mainly grow it for for the leaves, (pesto!) not the flowers, but African Blue Basil is different. The blue-purple flowers are one of the best parts of this plant, and in my opinion it’s a must in the pollinator garden. The bees absolutely love the flowers.

African Blue is also edible, with a strong basil taste with a stronger hint of the camphor flavour that most basils contain. You can use it for pesto, or any other recipe that needs basil. Of course, like all basils, you can eat the flowers too. And what beautiful flowers these make: blue-purple spikes atop all the stems, sprout upward in all directions.

The plant will grow as large as a small shrub in full sun. It also does very well in containers. Make sure it gets four or more hours of full sun for best results. The attractive purple veins on the leaves make African Blue Basil a great addition to a summer bouquet as well.

The other special thing about this plant is that it can’t be grown from seed, as it is a sterile hybrid of two other forms of basil. It must be propagated vegetatively. Here’s a little history of the African Blue Basil plant:

African blue basil (Ocimum kilimandscharicum x basilicum ‘Dark Opal’) is an accidental hybrid between an East African basil and a garden variety basil called ‘Dark Opal.’ The African parent is a perennial shrub from forests of Kenya, Tanzania and Uganda, valued for its camphor scent.

African blue basil was first seen in 1983 when Peter Borchard, owner of Companion Plants in Athens, Ohio, noticed it growing in the path between beds of the two presumed parents. The green-leaved East African basil parent grows to 6 feet tall in his garden. ‘Dark Opal’ is a small plant with deep purple leaves and a typical Italian basil flavor. Borchard dug the hybrid and brought it into the greenhouse, hoping to save seed, but the cross between the two species seems to be too far a stretch, because no seed formed. Borchard grew more plants from cuttings, and by cuttings has African blue basil entered the herb market.

You can dig them up at the end of the season, cut them back, pot them and bring them indoors for the winter, or you can take cuttings any time for new plants. It ought to be more widely available, but so far it seems to be still a bit of an undiscovered gem of the herb world.

Description from Amazon

African Blue Basil is a large shrubby form of basil that grows like a weed. The scent and flavor are more clove scented than Sweet Basil but it can be used for cooking. This plant grows to 4′ around and can grow in shady areas or in full sun for best flowering. It is very drought tolerant and the beautiful lavender pink flowers attract all kinds of bees to your garden. This basil is perennial but still sensitive to very cold weather. Easy to grow and never needs flowers pinched off because African Blue basil will not go to seed and die. This is a great landscape plant and indispensable in your herb garden for its color and fragrance.

To grow African Blue Basil, you must take cuttings from an existing plant, there are no seeds for this plant. It must get at least 2-3 hours of sunlight a day. It can be grown with filtered light such as under a tree or in a bright window indoors. If you forget to water it for about a month, and it wilts drastically, water it and it will look as good as new.

Prune occasionally for a more bushy form by cutting off the top about a third.

Cut some African Blue basil for herb bouquets and for garnish at the table.

  • Hardy in zones 9-11, elsewhere grow as annual or houseplant
  • Best indoor Basil. Use in salads and sauces.
  • Mature Height: 48 inches. Trim to keep shorter
  • Full Sun
  • Immediate shipping in a 4″ pot

$4.99 USD at time of publication Buy from Amazon The Gardenista editors provide a curated selection of product recommendations for your consideration. Clicking through to the retailer that sells the product may earn us a commission.

HOW TO PROPOGATE AFRICAN BLUE BASIL

It’s Sara Everett again, guest blogging for Hilary about one of our favorite bee plants: African blue basil. In addition to sharing lots of information about this bee magnet of a plant, including how to grow it yourself at low cost, this post also includes a special announcement: the winners of the Bee-Friendly Gardens book giveaway! Congratulations to the 5 winners whose names are published at the end of the post!

“The best way to help bees is to plant flowers,” says Hilary, when people want to know what they can do to help honey bees. “The amount of forage that bees have access to is directly related to honey production and hive health.” Hilary’s advice, along with the myriad things she has taught me about bees, got me to reimagine planting flowers; seeds in hand, I can see myself as a chef to the bees, ready to serve up the best flowers. I try to make sure my garden—or bee restaurant—has tons of menu options, and it’s fun to see the bees trying out the different plants.

Flowers are a bee’s primary food and nutrition source, and a flower seems to have it all: carbohydrate-rich nectar, protein-packed pollen, and a medley of nutrients entirely unique to the flower and the type of soil it grows in. That’s why it’s not only important to plant flowers, but to plant a variety of them.

One of my favorite staple bee flowers though is African blue basil, a plant that hums with bees from sunup to sundown every day in my garden. It’s a beautiful plant, with green-purple foliage; a plump, round growing habit; a bewitching herbal smell; and an eye-catching spray of purple and white flower spikes. For a basil, it’s a surprisingly forgiving plant: if you forget to water or prune an established African blue basil, it bounces back. It also makes great cut flowers!

As a bee plant, African blue basil tops my list because it’s so easy to propagate from cuttings. For new gardeners out there, propagation from cuttings is a cloning a technique, a way to grow lots of new plants from an existing plant, that works especially well for anything in the mint family—like basil.

A cutting will sprout roots directly from the stem if placed in water and given the right conditions. I first learned the details of this technique years ago by watching CaliKim’s episode about basil propagation on YouTube. Though she teaches about Italian basil, the concepts are the same for African blue basil, and I highly recommend that you watch it if you’re interested in seeing all the steps of propagation. My tutorial below is for to African blue basil and includes lots of photos and tips specific to this type of basil.

Tutorial: How to Propagate African Blue Basil

Time Commitment: 2-5 weeks (total project duration), 30-40 minutes (active project time)

Supplies:

  • Glass jar
  • Water
  • Scissors or pruners
  • Mother plant
  • 4-inch diameter pot or similar size container (with drainage holes)
  • Potting mix

Directions:

  1. Study your mother plant to find a branch to remove that will improve the health or shape of the mother and provide several good cuttings. I like to remove branches from dense sections to encourage airflow or to prune off some weight on a really laden branch.
  2. Once you have a branch, clip off all the flowers—buds included—and any damaged or dead materials.
  3. Inspect the branch. Identify a supple stem that’s purple or green with 4-8 leaf nodes (or more) that’s 6-10 inches long, and make a cut a quarter inch below the bottom node. A leaf node is where a pair of leaves meets the stem, and it’s the point where new branches will eventually sprout. Don’t pick a woody stem to root. Purple and green stems are the best.
  4. Now take a look at your cutting. The bottom 1-3 nodes will be underwater, so use your fingernails or scissors to gently snip off the leaves and buds just around those nodes. Let the other leaves be, as those will continue to carry out photosynthesis and supply the cutting with energy to grow roots.
  5. Repeat steps 3-4 for as many cuttings as you want. Fill your glass jar with water and stick the cuttings in, making sure that 1-3 inches of bare stems are submerged. It’s okay to crowd a bunch of cuttings in the same jar.
  6. Find a sunny spot you walk by at least once daily, like a kitchen windowsill. For the next 2-3 weeks, keep an eye on the cuttings. Remove any that die; keep the water level up; change the water if it becomes discolored; and wait for roots to grow.
  7. Once you have a lot of roots (see photos), it’s time to pot up the cuttings. This doesn’t take a lot of time, but it does take a gentle touch, especially if the roots of all your cuttings are tangled up. To pot them up, put a couple inches of soil in the bottom of the pot. Rest the roots a single cutting on top of that soil, and don’t worry about how the roots fall into place. If they’re coiled and tangled and a total mess, that’s okay. Resist the urge to spread them out. You’ll only break or bruise the delicate roots, and the plant can take care of growing more roots in the right directions. Gently sprinkle more soil on top of the roots until you fill the pot. Pack the soil down with your fingers just a little bit to stabilize the cutting, and water lightly.
  8. Repeat step 7 for all your your cuttings.
  9. Over the next 1-2 weeks, keep your potted-up cuttings in a sunny spot outside. Water gently every other day or so. Once you see lots of new growth or roots protruding from the drainage holes in the bottom of the pot, the plants will be ready to give away as gifts or to transplant into your garden!

Don’t try to root woody stems (bottom of photo), just supple green and purple ones.

Cool Plant Fact: Why does African blue basil bloom so much?

One of the reasons it flowers so endlessly is it’s a sterile plant. Since African blue basil never produces seed, its biological clock comes to a standstill. The clock stops ticking at the flowering stage of its life. It does not make a mature seed and die, as most plants are programmed to do. This happened because African blue basil is a hybrid, a plant produced when two types of basil were crossed by a plant breeder. This resulting sterility of the plant was viewed as a good trait because it gave the plant a long season of flowers. In San Diego, where we can garden year round, African blue basil blooms every day of the year.

Now, the announcement you’ve all been waiting for:

Congratulations to the Giveaway Winners!

  1. Carlamcgov whose favorite bee flowers are cosmos.
  2. Kelsi who plants catmint for her kitties and the bees!
  3. Randi who was inspired by his grandmother to plant lavender.
  4. David from Riverside who likes thyme.
  5. Kate F. from Maryland who plants bee balm which is native to her state.

Winners: you will be contacted through the e-mail address you provided to make your comment.

Thank you to everyone who participated and shared the contest!

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