Carolina allspice, also known as spice bush, is a member of the Calycanthus genus of flowering shrubs. This non-invasive plant is native to the south-eastern part of the United States. It is a commonly grown garden plant.
This perennial shrub, also known as the sweet shrub, is not the plant that produces allspice. The spice bush has very fragrant, fruit-scented flowers. Even the leaves exude a strong fragrance when they are crushed.
During a four-year-long plant-collecting expedition to the southeastern part of the USA, Mark Catesby identified many plants and birds.
As well as his study on migrating birds, he published works on the natural history of Carolina, Florida, and the Bahamas in the mid-1700s. Included in this work, are his illustrations depicting many examples of plants and birds from the region.
Calycanthus floridus was not yet named but was nevertheless identified in Catesby’s work. He described Carolina allspice as having a strong scent of cinnamon.
Although oils from the plant are used in perfumery, the Calycanthus also contains a toxin called calycanthine. Similar in structure to strychnine, this alkaloid was reputed as being the cause of death amongst sheep and cattle.
A 20th-century scientist, and professor of Chemistry at Oxford University, called Sir Robert Robinson was responsible for recognizing the structure of calycanthine and its place in the plant.
|Scientific name||Calycanthus floridus|
|Common names||Carolina allspice, Eastern sweet shrub, Spice bush, Bubby bush|
|Height||6 to 9 feet (2 to 3 m)|
|Width||4 to 6 feet (1.5 to 2 m)|
|USDA Plant Hardiness Zone||Zones 5 to 9|
|Native to||South eastern states in USA|
|Blooming season||April to July|
|Plant specific features||Stunning flowers|
How to Plant and Grow a Carolina Allspice
The planting hole should be twice as large as the pot or root ball. Don’t plant the shrub any deeper than the base of the stems.
When backfilling, tamp well around its roots and add a little compost, then mulch around the base of the plant. Take care that the mulch doesn’t come into contact with the stem, as this could result in rot.
Water well after planting, and continue until the excess water stops draining away freely.
Where to Plant
Calycanthus are such attractive flowering shrubs, that you will want to ensure that you plant them in a place where their beautiful flowers will be the star of the show. You can plant them in mixed, herbaceous borders, shrubberies, or in an informal garden setting.
Their flowers are highly scented, as well as being stunning. So it’s a bonus if you can plant them near a window or door to appreciate their perfume.
Carolina allspice are toxic plants, so do take care if you have small children.
They are deciduous, so you want to consider planting them near evergreen to give winter interest.
You can plant this shrub in a pot. Placed on a patio, or in a place of your choice, will enable you to enjoy its stunning blooms and fragrance to the full. You can of course move it around!
When to Plant
The best time to plant a Calycanthus is between the autumn and the spring.
Carolina Allspice Care and Maintenance
Carolina allspice is tolerant of many soil types. They will grow best in soil that is near neutral, neither too acidic nor too alkaline. If the soil is reasonably moist, the Calycanthus will grow faster.
Before planting, it is a good idea to mulch the soil with a reasonably thick layer of organic matter. This will improve the condition of the soil.
After you have planted the sweetshrub, water it regularly for the first growing season – and at least once a week for the first few weeks.
During the summer months, especially, it is very important to provide the shrub with sufficient water to encourage growth and maintain a healthy plant. The new Carolina allspice should never be left to dry out.
Once established, you can reduce watering. The plant is native to temperate climates and unless there is a prolonged dry, hot spell, you shouldn’t really have to give it much supplementary water at all.
Renewing the mulch every autumn is a good idea. It will help to feed your plant and cut down on weed growth around the base of the Carolina all spice.
C. floridus will thrive in full sun, but it is better to find a spot that receives a little shade as well.
Pruning and Repotting
Pruning is recommended for the sweet bush shrub to keep it healthy and to keep it in shape. Pruning should be carried out once the flowers have finished.
This will encourage plenty of new growth to develop in time for the following year’s blooms.
This is the time to check the shrub for any dead or diseased branches. Always remove such decaying woody growth promptly to minimize the risk of pests and diseases.
You may find the Calycanthus throws out new suckers from its base; you can leave these in place if you are happy and have the space for the shrub to spread. If not, remove them with a sharp knife, taking care to make straight cuts to prevent infection of the plant tissue.
Propagating is best done by taking softwood cuttings in the Spring.
But it is also possible to raise new plants from seed, although if you are raising new plants from a hybrid plant, the new seedlings will probably not be the same as the parent plant.
You can plant the seeds directly in the soil, close to where they would naturally fall from the shrub. To have the highest success rate in germinating Carolina allspice seeds, place them in a plastic bag, wrapped in a damp paper towel.
Keep them in the fridge for two or three months before planting the seeds in seed trays filled with potting compost.
You can also propagate C. floridus from the root cuttings, which can be separated and re-rooted.
Pests and diseases
Carolina Allspice requires little maintenance; providing it is healthy and given good growing conditions, then pests and diseases shouldn’t be a problem.
Occasionally, powdery mildew can infect the shrub, but this can be treated with horticultural oil.
Temperature and Humidity
Growing zones are recommended as hardy between zones 5 and 9. Some cultivars are a little more tolerant, of both sun and cold.
Humidity requirements are moderate. The Calycanthus should be kept damp, but not wet. Soil should be moist but not waterlogged.
Other Uses for Carolina All Spice
The flower of the sweetshrub is excellent for cutting. Chopped sweet bush bark and leaves, as well as their flowers and twigs, are frequently included in a mix of potpourri.
The compounds in the leaves make them useful as insect repellant, perfume, and even a disinfectant.
Because this is a deer-resistant plant, it is sometimes planted as a hedging shrub to discourage deer from entering gardens.
Types of Calycanthus floridus You Can Grow
There are a number of hybrids available. Some are more fragrant than others, some more free-flowering.
Calycanthus floridus “Venus”
Venus is one of the most fragrant cultivars available. The flowers are large, white, and exude a sweet melon-like perfume.
Calycanthus floridus “Hartlage Wine”
Hartlage Wine is the cultivar name given to the original cross between C. chinensis and C. floridus. This hybrid combines the larger flower size of the Calycanthus chinensis with the brighter color and stronger fragrance of the C, floridus.
Before purchasing a Carolina allspice, it’s best to wait until it is flowering. This is the time that you can see for yourself the flower size and color, as well as sampling the scent before deciding on a variety.
Calycanthus floridus “Solar Flare”
Similar in flowering appearance to “Hartlage Wine”, but with larger leaves. This makes the flowers appear a bit smaller. This cultivar appears to be more cold-hardy than “Hartlage Wine”.
Despite its multitude of common names, Carolina allspice is a unique flower to have growing in your garden. The flowers are formed like the blossom of water lilies, growing amongst deep green, glossy foliage that turns yellow in the fall.
The first time you experience the sweet, lingering aroma of its scent, you will be captured!
*image by I_love_life/depositphotos