Common name: Four o'clock or Marvel of Peru
Mirabilis jalapa are bushy annuals with colorful flowers and a sweet citrus fragrance.
Because of this attribute siting a container near the house door,a sitting area or planting alongside a footpath will give you the full benefit of their fragrance.
They originate from the Andes Mountains in Peru hence the common name "Marvel of Peru"
They come in various colours, e.g. Yellow, Pink, Rose, Salmon,and White, and will flower from mid summer up until the first frosts.
The individual flowers open in late afternoon, usually between 4 pm and the onset of darkness. (hence the common name).
The plants may grow to around 90cm (3ft) in height and spread to around 60cm (2ft) when grown in the border but are usually much smaller if grown in containers.
They prefer to be sited in moderately fertile, moist but well-drained soil in full sun although they will tolerate partial shade.
Seeds can be sown directly into the soil after all danger of frost has passed, or earlier in seed trays at a temperature of 13°- 18°C(55°- 65°F)
If grown in the border choose a site that is sheltered from cold, drying winds and provide a dry mulch in winter to protect them from excessive winter wet.
If the plan is to grow Mirabilis in the border then it is advisable to do this only in the warmer areas of the UK.
Otherwise the best advice would be to grow them in containers and keep them outside over the summer, then overwinter them in a frost free greenhouse or cold frame.
Keep the containers well watered and fertilize* with a balanced or high potash during the growing season.
* Feed monthly if in the border, weekly if in containers.
Pests & Disease:
Plants may be attacked by aphids and slugs / snails but are generally disease free.
Some people may get a rash from handling the plant so always wear gloves and cover the arms when working with the plants.
The seeds can be toxic if ingested.
Soak seeds overnight in warm water to hasten germination, then sow them in pots or trays of seed compost and place in a propagator or on a hot bed set to give a bottom heat of around 13°- 18°C(55°- 65°F)
Germination should take place within a week.
If large enough to handle prick out seedlings into individual 75mm (3") pots of potting compost.
Grow them on in a frost free place and gradually harden them off until planting out time.
Week 10 -12:
Divide the tubers of established plants grow the previous year and grow them on in suitable sized pots of potting compost.
Plants grown from divisions usually flower sooner than those grown from seed.
If plants were grown in the border the previous year you may find self seeded seedlings in the border, these can be carefully lifted and potted up and treated like seed sown or divided plants.
Pinch back the main shoot on new plants to promote a bushier plant and more flowering.
Circa Week 40-44;
If required collect seed after flowering and keep an eye on the weather forecast for pending frosts.
If frosts are forecast put containerised plants in a frost free greenhouse or coldframe.
Plants grown in the borders should be cut down to soil level and the black, carrot-like tubers lifted, in milder areas a deep organic mulch may be sufficient to protect them from the ravages of the winter.