Mirabilis (or Four O'Clocks / Four O'Clock Flowers) are half hardy and can tolerate winter and spring temperatures down to around -5C. They are best protected from light frosts and require mild to warm temperatures to come out of dormancy. It is advisable to start them off indoors or in a cool greenhouse in the spring, or to wait until late April before planting them directly outside.
— For best results, pot up and grow on in a greenhouse between March and April, they can then be transplanted outside in early summer. Alternatively, you can Mirabilis plant them directly outside in late Aril or early May.
— Plant the bulbs around 15-20cm deep in borders or pots with the pointed side facing downwards and the crown level with the soil surface. Any shoots can be left exposed above the soil surface.
— Space the bulbs around 20-25cm apart in borders.
— Choose a position in full sun with free-draining soil.
— If planting in patio containers, we recommend using a peat-free multipurpose compost.
— Water-in after planting continue to water regularly when in growth.
— Allow the soil to become almost dry between watering. Don’t allow dormant bulbs to sit in wet, soggy and cold soil.
— Cut back flower stems to 1” above ground level in autumn. Move containers with Four O'Clocks into a frost-free location for winter or lift and store the bulbs in a cool but frost-free place until the following spring. In mild/coastal areas, Mirabilis planted in borders should be covered with a mulch over. Mirabilis bulbs will not require watering during winter storage.