A favourite for making ‘’White Gardens,’’ and ‘’Moon Gardens,’’ White four o’clock is a charming night-blooming plant with a lovely aroma. The plants grow between 1 to 3 feet tall and will bear large numbers of pristine white, trumpet-shaped, 1 to 2 inches wide flowers.
The flowers tend to open in late afternoon, or earlier on cloudy days, to be replaced by another one the following day. A great addition near terrasses and patios where you spend your evenings and for gardeners who like to tend to their garden in the later part of the day.
- Life Cycle: Perennial, often grown as an annual
- Days to Maturity: 90-110
- Planting Depth: 1 cm deep
- Plant Spacing: 60-80 cm
- Growth Habit: 60-90 cm tall
GROWING INSTRUCTIONS
The bushy, flowering perennial produces attractive, brightly coloured blossoms. A native to South and Central America, the fragrant, trumpet-shaped flowers are grown in colder regions as annuals. The shrub-like branches sprout from underground tubers and produce oval leaves.
Mirabilis jalapa get their common name, four o’clock, from their blooming habit. The flowers open late in the afternoon and stay open until the next morning. It’s a fast-growing plant that can quickly take up a lot of space in the garden.
Seeds can be started indoors six to eight weeks before the last frost date in your area. Use biodegradable peat or coco pots to avoid disrupting the long taproot when transplanting. Four o’clock will benefit from fluorescent lights and heat mats, or simply sprout seeds in a warm, south-facing window.
Outdoors, seeds can be sown directly after all danger of frost has passed. Plant seeds 5 mm deep and space 30-45 cm apart. Germination should occur in 1-2 weeks when kept at an even 21 degrees. Seeds can be scored with rough sandpaper and soaked in water overnight to improve germination rates.
Four o’clock will bloom most brilliantly in full sun. Rich well-drained soil is the ideal spot to grow the flowers. Stay on top of the watering, do not let them dry out. Mulch around the base of the plant to keep water from evaporating. Plants also grow well in containers, but will require more frequent watering. Feed once in the spring with a balanced fertilizer and monthly thereafter. Rich soils may not need additional feeding throughout the season.
The main stalk can be pinched out when the plant is young to encourage a sturdy structure and more flowering. Plants can also be sheared back by a third in dry weather to rejuvenate new growth.
Four o’clock plants do exceptionally well in hot climates and are grown as annuals in cold regions. However, there are ways to preserve or propagate your plants for future seasons. When plants are done blooming in the fall, dig up the roots and store them for the winter. Keep them in a cool and dark place to prepare them for replanting in the spring.
Self-sown, spring seedling volunteers can easily be dug up, relocated and transplanted around the garden. Be advised that all parts of the four o’clock plant are known to be toxic to humans and animals. As long as it’s not ingested, the four o’clock plant is perfectly safe, fragrant and exquisite to behold.
QUICK FACTS
- Four O’clock flower, also known as Belle de Nuit, originates in the dry tropical areas of Peru all the way up to Mexico. Cultivated and selected for various colours by the Aztecs and other nations for thousands of years, it was first brought to Europe by Spanish explorers during the mid-1520s.
- USA founding father Thomas Jefferson is credited has having been the first to grow Mirabilis in North America in 1767.
- The plant was very popular all over North America until the 1920s when it suddenly lost its popularity for no apparent reason. Its ability to reseed itself made it a survivor near the foundations of old buildings and stone walls of abandoned gardens.
- Four o'clocks can be stored overwinter for more established plants the following year. Simply dig out the tubers, trim them back and store them in paper bags in a dark and dry place that doesn’t freeze.
- Most parts of the plants have medicinal properties and the flowers are used nowadays as a crimson red food colouring agent added to cakes and jellies. The colourful flowers are also used for dying traditional handloom products.
- Four O Clock seeds will remain viable for 2 years if stored in a cool, dark place, ideally between 4 and 10⁰C. After that, the germination rate may start to go down.
