Rosemary Is Now A Salvia

Here is another name update, for those of you who are interested in keeping up with taxonomy changes. Rosemary, formerly Rosmarinus officinalis, is now a Salvia, Salvia rosmarinus (pronounced SAL-vee-uh rose-ma-REE-nus). Rosemary is an aromatic evergreen shrub, often sold in 4-inch containers in garden centers. 

Rosemary is among my favorite herbs because of the wonderful resinous scent of the needle-like foliage, the flavor it imparts to food, low maintenance requirements, and deer resistance. The scent is not noticeable unless the leaves are disturbed. I trail a hand along the foliage whenever I pass it to release the fragrance. Sometimes I catch a delicious whiff when the sun shines directly on the plant and breezes are few. For delicious Italian bread or pizza crust, add chopped leaves (no stems) to your bread maker about half-way through its kneading process. Adding leaves too early can hamper the yeast action. A sprinkle of fresh leaves added to simple roasted potatoes elevates the dish from plain to gourmet.

Cultivars vary in form from upright to spreading. Most have tiny, light blue flowers in late spring, summer and early fall. Bees and butterflies visit the flowers, making them a good choice for pollinator gardens. Plants can be used in containers, as low hedges, or as groundcovers. Because deer generally avoid Rosemary, I have spaced plants around the garden, hoping they will work as horticultural security guards to protect my Hydrangeas and Gardenias from deer damage. There is not enough sun in the Hosta beds to keep Rosemary healthy, so I have not tried it in the shade beds, but I drop dried-out Rosemary stems from old flower arrangements in the Hosta area. It cannot hurt, right?

Years ago, I read that Rosemary was a good companion to hybrid tea roses, since it was reputed to repel aphids. I tested that theory and found that aphids like Rosemary, too. This is the only insect that has bothered it in the Snoddy garden, but others have mentioned problems with spider mites and mealybugs. I find it to be a low maintenance shrub. Plant it in a boggy soil, however, and you can kiss it goodbye. Plants require full sun and good drainage. Provide them with a loose soil of nearly neutral acidity. They even do well in rocky or sandy areas, and are resistant to damage from salt breezes.

Rosemary’s aromatic foliage makes it a good addition to winter cut flower arrangements. It is cold hardy in zones 8-10, and maybe even colder if grown in a protected location. In zones 7 and colder, grow Rosemary as an annual. It can be attempted as an indoor houseplant, but these usually fall prey to insect damage or overwatering.

Regular removal of stems for flavoring or cut arrangements serves to keep the plant compact and bushy, but with time Rosemary becomes woody and ugly. A severe pruning leaves an unattractive, stubby-looking plant, so when yours reaches that too-big stage, remove it and replace it with a new plant. Plants are best propagated from stem cuttings or layering. Seed starting is slow.

Of the cultivars, S. rosmarinus ‘Tuscan Blue’ is a fast grower. ‘Prostratus’ can be used as a groundcover or in a container, but will eventually reach heights up to two feet. ‘Arp’ is reputed to be more cold hardy than the others. S. rosmarinus ‘Officinalis’ is widely available. ‘Albus’ has white flowers and ‘Majorca’ has pinkish flowers but it is a stingy bloomer.

Rose of Sharon, an Old Fashioned Heat Lover

Althea or Rose of Sharon (Hibiscus syriacus, pronounced hi-BIS-kus seer-ee-AY-kus) is a fast growing, low maintenance shrub. It prefers full sun or slight shade, grows in any type of soil, and is adaptable to most soil acidity levels. Plants can reach twelve feet tall and up to ten feet wide, although most mature at a lesser size. They prefer hot weather, and have the charming characteristic of flowering while everything else is drooping in the heat. The individual flowers look like a smaller version of giant tropical Hibiscus but unlike tropical Hibiscus, they are perennial in zones 5-9. They can be planted closely (five feet apart) to create a flowering hedge.

Rose of Sharon begins to bloom in early summer and continues until fall. Plants bloom on new growth. Tip pruning in late winter will encourage new growth and result in more flowers. Please use hand pruners, not powered hedge trimmers. Flowers come in shades of lavender, pink, blue, white, and bi-color. Older varieties produce large quantities of seed that often spread themselves about too enthusiastically for the typical gardener. This dampened their popularity until hybridists introduced a number of low-seed or no-seed cultivars.

Cultivar ‘Diana’ has pure white flowers that mix well with other flowers and shrubs, and is a strong performer. Several semi-double or double-flowered varieties are available. Some of the newer introductions, like ‘Lucy’ or ‘Blushing Bride’ produce fewer seeds. Fully double Blueberry Smoothie™ and Peppermint Smoothie™ are sterile. Proven Winners ‘Sugar Tip’® has a variegated leaf and pale pink, double flowers. It is seedless and semi-dwarf, reaching six feet. Rose of Sharon is still on the Invasive List in Kentucky and Virginia.

Drought-stressed plants that suddenly receive an onslaught of rain are prone to dropping buds in a condition labeled Flower Bud Drop. Provide irrigation in extended drought to avoid this. Although rare, Leaf Spot and Leaf Rust can damage plants. These are treated with a foliar anti-fungal. Plants are occasionally bothered by Japanese Beetles or aphids. They are deer resistant. Hummingbirds and bees, especially larger bees, love the flowers. For this reason, avoid using insecticides or systemics to combat insect infestations. Instead, hand pick Japanese Beetles and use a strong spray of water to wash aphids off buds and tender new growth.

After several years, Rose of Sharon tends to lose its foliage at lower levels. If this is a concern, plant it behind a perennial that will conceal its lower regions, or intentionally prune it to a single-trunk tree form while the plant is young. This is a hardy, long-lived, low-maintenance shrub and is ideal in a pollinator garden or children’s garden.

This Rose of Sharon is blooming in a parking lot island at my local pharmacy, surrounded by asphalt pavement.

A bee enjoys this bloom.

Portulaca, A Flowering Succulent for Heat and Dry Soil

My love for Purlsane began when I inherited a pair of concrete planters that sat atop brick steps in full, baking, South Carolina sun. Nothing would survive in that spot until I found Portulaca (pronounced por-chew-LAY-kah), commonly known as Purlsane. This South American native flourishes in heat, laughs at humidity, and withstands neglect. Too much water will cause rot, so well-draining soil is a must.

Portulaca is a mat-forming annual succulent that reaches heights of four to six inches. Leaf forms are either needle-like or rounded and fleshy. The colorful blooms in shades of yellow, red, pink, coral, white, or magenta open in the morning, then close at sundown or when pollinated by a visiting bee. Flowers may not open on cloudy days. The ‘Yubi’ series and the ‘Afternoon Delight’ series stay open longer than other varieties. This means it is good plant for daytime enjoyment, not so good for evening entertainment. Plants grow quickly from transplants. They will sometimes reseed. They do well in hanging baskets and rock gardens.

A weedy form of Purlsane, Portulaca oleracea, is spread around by birds, winds, and via animals’ digestive systems. The foliage resembles its round-leaf cousin, but flowers are invariably yellow. They are hard to eradicate due to an extensive root system. This “weed” is a food for wildlife. Its leaves are edible by humans but are harmful to dogs, cats and horses if eaten in large quantities.

Portulaca is generally trouble-free, bothered occasionally by spider mites, aphids, or slugs.

A pair of hanging baskets with Lantana and Portulaca

Calycanthus, Carolina Allspice or Sweetshrub

Sweet Shrub is a homely shrub with a heavenly scent. Native to the southeast, Sweet Shrub grows in part shade. It will reach heights of six to ten feet, and spreads indefinitely by suckering. Flowers of the species are nondescript, wine colored, and easy to overlook. Newer cultivars have larger, more attractive flowers but may not be as fragrant as the older type. The flowers have a scent that is described as a cross between strawberry and kiwi. Bruised foliage has a pleasant scent also.

Sweet Shrub (Calycanthus floridus, pronounced kal-ee-KAN-thus FLOR-id-us) is perennial in zones 4-9. It will reach heights up to 12 feet in clay or loamy soil with an acidic or neutral pH. Flowers have strap-like petals (tepals) in shades of burgundy to brown. Newer cultivar ‘Athens’ has white flowers and ‘Aphrodite’ has a brighter red bloom than the straight species. ‘Hartlage Wine’ has larger, showier flowers.

Locate Sweet Shrub in a woodland garden to seating or pathways so that its fragrance can be enjoyed. Flowers are popular with pollinators and shrubs are usually ignored by deer.

This is the native version of Calycanthus, Sweet Shrub. Newer cultivars have larger flowers. Reports indicate that newer cultivar ‘Venus’ is equally fragrant.