Cleomes flower all summer, and love the sun and heat

Cleome 'Sparkler' Mix. Picture courtesy Nu-Leaf NurseryCleome 'Sparkler' Mix. Picture courtesy Nu-Leaf NurseryCleomes can be cultivated in gardens throughout South Africa and look great planted amongst other water-wise, summer flowering annuals and perennials. Growing them in garden beds or pots is simple and rewarding, so read more below about growing these summer annuals.

When you look at a cleome plant, it is easy to understand how they earned their common names:  Spider Flower, Spider Legs, Grandfather’s Whiskers, and Cat’s Whiskers, as these plants are famous for their clawed-looking petals and very long and wispy, hair-like stamens with yellow-orange anthers, that stick out from each individual flower in the large clusters of spherical flower heads. The blooms start opening at the bottom of the stalk and move upwards, and the petals come in bright shades of pink, rose, lilac-pink, and white, blooming throughout summer until the first frosts.

The flowers may be visited by nectar eating birds like sunbirds, as well as moths, bees and butterflies, to name but a few, but in their native tropical habitats, cleomes are pollinated primarily by bats. Many types have no noticeable fragrance, while others are very fragrant, and the scent is often described as musky, sweet and pungent, or spicy, and as one you will either love or hate. Cleome can be an excellent and striking cut flower if the scent is not considered disagreeable.

As the flowers fade, they are followed by thin green seedpods that ripen to brown and split open to disperse the small seeds, and these thin, spidery green seedpods also contribute to their common names. Older cultivars, such as the “Queen series”, produce viable seed and will potentially self-seed in nearby areas, and can become invasive, but the newer hybrids are sterile and do not produce viable seed.

The very attractive green palmate leaves are sticky, with 5 to 7 leaflets that have a strong and sometimes unpleasant fragrance and sharp spines at the base of each leaf. However, most of the newer cultivars are odour and thorn free, making them more desirable for gardeners.

Cleome is a genus of about 170 species in the caper family (Capparaceae). This family of robust annuals and shrubs are indigenous to tropical and subtropical areas worldwide, but only a few of the annuals are commonly cultivated. The older garden varieties of cleome are tall, producing their blooms on stems which can reach as high as 150cm, making them ideal for the back of flower borders. Newer hybrids are much shorter and more compact, but this does not inhibit their blooming potential, and these dwarf varieties are perfect for smaller flower gardens.

Cleome hassleriana has been a garden favourite since the 1800’s, and this annual, which comes from South America, is found in Paraguay, Uruguay, Argentina and southern Brazil. It has also been introduced to South Asia, including the Haor area of Bangladesh and India. It remains a garden favourite and is commonly cultivated in temperate regions as a half-hardy annual, and numerous cultivars have been selected for their flower colour and other attributes.

The "Queen" series includes the cultivars 'Violet Queen', 'Rose Queen', and 'White Queen', and the cultivar 'Helen Campbell' has gained the Royal Horticultural Society's ‘Award of Garden Merit’. It is believed that the plant from which the Cleome ‘Queen Series’ was developed originally came from the West Indies and was introduced into the United States in 1817, where it gained almost immediate popularity despite the fact that the foliage has a strong odour along with sticky leaves and  spines at the base, because it was a curiosity with its extraordinary blossoms produced on top of  stems, 1.2 to 1.5m tall.

In his 1851 book, The Flower Garden, Joseph Breck wrote, “This is an elegant tribe of plants and very curious in their structure…However beautiful and curious these plants may be, and desirable for show, they are repulsive to the smell and unpleasant to the touch, and, therefore, will not be favourites.” Despite Breck’s commentary cleomes enjoyed many decades of popularity before falling out of favour with gardeners.

By Victorian times, cleomes were being grown in greenhouses as potted plants, and as the “cottage” style of gardening emerged during this era, cleomes became a popular component of this style of garden, especially in America and Europe, but strangely, not so much in Britain.

During the 20th century, as gardens became smaller and gardening, in general, became less popular, cleomes fell out of favour, and only recently has there been resurgence in popularity of these beautiful plants, largely due to the beautiful, dwarf ‘Sparkler Series’ of cleome, and the return of wilder more natural looking landscapes, and cottage styled gardens.

The Sparkler™ series was the first F1 hybrid cleome developed. It is more vigorous and heavier blooming than the Queen series, and only grows about 60 to 90cm tall, making it much more compact growing than older varieties. This smaller size allows modern gardeners to grow this old-fashioned annual in smaller gardens without overwhelming the design. As they are shorter and bushier, the Sparkler™ series is also an excellent choice for containers. This hybrid is easy to grow, adapting to most soil types and growing conditions needing only sun and nutrients in the soil. This cleome produces sterile seed so it is not invasive, and it is both heat and drought tolerant – any South African gardeners dream come true.

Sparkler Mixed is available in trays of seedling at garden centres, and can be ordered from online stores.  Nu-Leaf Nursery stocks large trays of 128 or 200 seedlings and delivers in Gauteng. Click here to read more. 

Uses:

In their native range’s, cleomes have earned many regional common names and have been enjoyed by indigenous peoples for both their culinary and medicinal benefits.

 In southern and South Africa, from Limpopo to Namibia, we have our own cleome (Cleome gynandra) commonly called: “Oorpeultjie”, “snotterbelletjie”, “African cabbage”, “spider-wisp”, “murudi”, “morotho”, “lerotho”, and “mazonde”. African cabbage is of economic importance as it is among the herbs that are used as indigenous vegetables in rural areas of southern Africa. Cleome leaves are usually about 4% protein, and this herb is also a rich source of nutrients, especially vitamins A and C, and the minerals calcium and iron, and analyses have shown that it is rich in minerals, vitamins and amino acids. Due to its anti-inflammatory properties, cleome is sometimes used as a medicinal herb.

Cleome was also known as “Navajo spinach” because of its importance to Native Americans as a food and medicinal crop. Called “Waa” by Navajo Indian tribes, cleome was used to treat stomach problems, eye inflammations, and as a gargle for sore throats. It was also used in culinary dishes as we use spinach, and the leaves were eaten raw in salads or cooked in stews, soups, or chilli. The small seeds of cleome, which look like little snail shells, were also eaten, either raw or ground into flour.

In addition to its culinary and medicinal uses, cleome was also used to make dye for baskets and rugs, and paint was made from cleome and used to decorate pottery. Despite the fact that many cleome species have earned common names, such as “stinkweed”, because of foul smelling glands on their foliage, cleome was also made into soaps and deodorants.

In the Garden:

Older taller varieties of cleome are planted in groups towards the back of mixed flower or informal shrub borders to add dramatic vertical accent, and they blend effortlessly with many other water-wise and sun loving annuals and perennials.

The newer dwarf varieties like Sparkler are perfect for smaller gardens and containers, where they also add good accent, while still remaining compact enough to plant with smaller sun loving summer annuals and perennials.

Cleomes contrast well when combined with summer annuals, such as sunflowers, zinnias, cosmos, salvia, or celosia.

Because the flowers last long in a vase, cleomes are wonderful for cutting gardens, and a couple planted near the vegetable patch will help to attract beneficial insects and pollinators to the crops. In fact, this species is part of the Royal Horticultural Societies “Plants for Pollinators” initiative to showcase plants which support pollinator populations by providing ample amounts of nectar and/or pollen.

 Image by Hans Braxmeier from Pixabay Image by Hans Braxmeier from PixabayCultivation/Propagation:

The Spider Plant grows well throughout South Africa in full sun, but in very hot and dry regions it can be grown in some shade. It thrives in light, fertile soil but is adaptable to most conditions as long as the soil drains well. Potted specimens will grow in any well drained potting medium. If your garden soil is fertile you may not need to fertilise, but potted plants will need regular feeding to perform well. You can feed every 6 weeks or so with a granular or liquid fertiliser for flowering plants. Avoid high nitrogen feeders as they will produce lush foliage at the expense of the flowers.

The plants grow quickly and hold up well during mid-summer’s scorching heat, and once established they are drought tolerant and will only require a deep watering about once a week, depending on the quality of your garden soil. In fact, overwatering results in prolific leaf growth at the expense of the flowers. Potted plants will require more frequent watering, so check them regularly during hot weather.

Although cleomes have deep, strong taproots and do not normally need staking, try to protect your plants, and especially the taller varieties, from very strong winds. Spacing seedlings correctly is always important, but especially if you are growing cleomes in humid regions, as good air flow between the plants is essential to help prevent fungal diseases, so check the plant labels or seed packet for the correct spacing.

The old varieties of cleome will self-seed freely in the garden and can become invasive, so if you don’t want them to invade other spots in the garden, remove the seed pods before they burst open. Deadheading is not required but many gardeners remove the spent flowers to keep the plants neater looking.

For the average garden it is easiest to purchase trays of cleome seedlings to plant out as soon as all danger of frost is over.  However, if you have a large garden and want to sow seeds, they can be sown directly into garden beds or seedling trays, in spring or early summer when all danger of frost is over, germinating best in soil temperatures between 21 and 22°C.  

Cleome requires warm weather and a long growing season to fully develop from seed, and the seeds require light to germinate so do not cover them with soil and place the trays in good light. Seed germinates in 10 to 18 days, depending on soil temperatures and weather conditions. Patience is necessary during this phase as germination may be erratic from year to year, but the plants should start blooming within 11 to 14 weeks after sowing.

The ‘Queen Series’ will have a better germination rate if they are chilled for 4 to 5 days prior to planting. To chill the seed, evenly spread them on a moist, not wet, paper towel, fold, place inside a zip-lock bag, and keep in the refrigerator. The hybrid ‘Sparkler™ Series’ does not need to be chilled prior to germination.

Seeds may be started inside; however, a complicated schedule of lighting, temperature fluctuation and bottom heat is required for indoor germination, and is usually not worth the effort of the regular gardener.

Problems, Pests & Diseases:

Overall, cleome is a tough annual and suffers from no serious insect or disease problems. Aphids, spider mites, and whiteflies can be a problem. It is susceptible to powdery mildew and rust in hot, humid climates; therefore, to help prevent infection, it is important to space the plants properly to allow for better air circulation.

In order to avoid disease issues the next year, remove dead plants after they are killed by frost.

Warning:

Cleome hassleriana is listed as non-toxic to humans, dogs, cats and horses.