Better Basils: New Disease Resistant Basil Varieties

This article by Theresa Mieseler originally appeared in the May/June 2020 issue of Northern Gardener.

Basil is a pleasure to touch, smell, taste and harvest. It pairs with tomatoes as deliciously as strawberries pair with rhubarb and can even be used in desserts! While northern gardeners love the traditional sweet basil (Ocimum basilicum), basil downy mildew (BDM) disease and a desire for something different have led gardeners to explore basils grown across the globe to find disease resistant basil types.

Of the 10 basils below, I have grown eight without any disease issues. The other two are newer disease resistant basil varieties that should do well in northern gardens. Try one or more this season to add oomph to your garden and your cooking.

Mrihani Basil (O. basilicum)

disease resistant basil mrihani

Photo: Theresa Mieseler

About 10 years ago, I came across the work of plant explorer Richo Cech, who was collecting varieties of basil from southeast Africa. One of those varieties was Mrihani basil. I conducted several unofficial experiments in my greenhouses. When downy mildew affected my Genovese basil crop, Mrihani basil was on the same growing bench. None of the Mrihani basils were infected.

Some hybridizers are working on a cross of Mrihani with other basils, but I prefer Mrihani as it is. It has superb fragrance and flavor. I use it in any recipe calling for basil. The leaves are light green and ruffled, sometimes purple streaked, and it bears small lavender flowers.

Mrihani flowers later in the summer, which gives more time for the plant to grow and produce foliage to cut and use. It has a sweet perfume with fennel undertones. It dries well, too, unlike most basils.

Prospera® Basil (O. basilicum)

Prospera® basil leaves are medium to large and dark green with a traditional sweet basil aroma and flavor. Seed is certified and protected internationally by Plant Breeders Rights. No symptoms of downy mildew were found on plants in a Cornell University evaluation in 2018.

This is a beautiful disease resistant basil plant that is slow to bolt. The name Prospera is a play on words between the disease Peronospora and prosperity. Prospera has been tested globally and commercial seeds are now available.

Rutgers obsession DMR basil

Rutgers Obsession DMR basil growing in greenhouse
Photo: VDF Specialty Seeds

Rutgers DMR (O. basilicum)

Rutgers downy mildew resistant (DMR) basil seeds have been sold by VDF Specialty Seeds to commercial basil growers since 2018. The following two DMR basil varieties are now available to home gardeners.

Rutgers Devotion-DMR is an excellent, aromatic sweet Genovese-type basil for container and garden plantings. Devotion grows 2 feet tall, with a uniform, upright habit and dark green leaves that are flat to cup shaped. While it produces many harvests in a season, it requires careful handling as the leaves bruise easily.

Rutgers Obsession-DMR is a compact (26 inches tall), vigorous grower that is an excellent edible landscape plant. Its dark green, thick, glossy leaves are up to 2½ inches long. It is slower to flower than the Rutgers Devotion-DMR. When it is cut back in midsummer, it regrows prolifically and allows for more harvests.

Thai Sweet Basil (O. basilicum)

Thai basil has small, narrow leaves, purple stems and pink-purple flowers with a hint of licorice. A favorite addition to noodle soups, fried rice and chicken dishes, you can also deep fry the leaves to use as a garnish on the dinner plate.

Basil varieties other than (O. basilicum) offer different looks, tastes and uses.

Green Pepper Basil (Ocimum selloi)

green pepper basil

Green Pepper basil
Photo: Theresa Mieseler

Green pepper basil is a novelty basil. A sturdy, upright tender perennial, it grows about 30 inches tall with long, serrated, deep forest-green leaves. Its fragrance is a cross between sweet basil and green bell peppers and its flowers are pink with reddish bracts. It is not my favorite for culinary uses, but as an ornamental, it is very showy, disease resistant and cold tolerant. Grow it in a container. Can you eat it?

Kivumbasi Lime Basil (O. canum)

Native to Zanzibar, Kivumbasi lime has a fruity flavor in the leaves and is delicious added to tea, fish and seafood. The plants are compact with many branches, growing to a height of 2 feet with woody and hairy stems. The narrow oval leaves are 3 inches long, pointed at both ends. Flowers are white or pale purple.

Holy or Sacred Basil (O. tenuiflorum)

The species tenuiflorum, meaning slender leaves, is known as holy or sacred basil. A hairy plant that is typically vigorous and upright, it’s common in India and Taiwan, as well as northern and eastern Africa. This basil is not used in cooking, but is typically consumed as a tea. Where Ayurvedic medicine is practiced, holy basil is known as “The Queen of Herbs” for its therapeutic properties.

amrita tulsi basil

Amrita Tulsi basil
Photo: Theresa Mieseler

Tulsi Amrita Basil (O. tenuiflorum)

Tulsi Amrita basil has green leaves with purple highlights on a bushy plant. It is used to make tasty Tulsi tea, which provides gentle stimulation to body, mind and spirit. Enjoying a cup of Tulsi tea is a good way to begin the day.

Tulsi Vana Basil (O. gratissimum)

Another name for Vana basil is clove or tree basil. The largest growing basil in my garden, it reaches a height of 5 feet. Native to India and East Africa, it is a wild species brought into cultivation. The large hairy leaves grow 6 inches long and 3 to 4 inches wide. Vana basil is highly fragrant and keeps its aroma for several years when dried. As I wrote this article, I sipped a cup of clove-scented Tulsi Vana tea that I dried last summer. Delicious! Can you eat it?

Theresa Mieseler and her husband, Jim, operated Shady Acres Herb Farm in Chaska for 39 years. Currently she writes a bimonthly herbal newsletter and is the author of Beyond Rosemary, Basil, and Thyme. Her website is www.shadyacres.com.

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