Although four o'clock (Mirabilis jalapa) is commonly grown from seed, the plant can also be grown from long, carrot-like tubers. Also known as "marvel of Peru," four o'clock is a sure-fire winner in the landscape, with attractive, bushy foliage and clusters of colourful blooms.
Four o'clock opens in late afternoon and the fragrant blooms are present all night long. Surprisingly, one plant can bear a variety of distinct colours at the same time, including solid colours, splotches and stripes. Four o'clock is hardy to USDA Zones 10 and 11.
Plant four o'clock tubers in early spring. Select a planting spot with full well-drained soil where the plant will be exposed to full sunlight of partial shade. Allow plenty of space, as four o'clock s are bushy plants that can eventually spread up to 5 feet across.
Dig a hole—using a bulb planter, a spade or a garden trowel—and plant the 4 o'clock tuber with the same orientation as a carrot, pointed end down. The hole should be deep enough that the top of the tuber will be covered by 2 inches of soil. Cover the bulbs and gently firm the soil.
Water the tuber deeply enough to saturate the soil immediately after planting. After planting, four o'clock s must be irrigated only during hot, dry weather. Water the plant deeply, then allow the soil to dry out slightly before watering again. Water lightly during the winter if the weather is dry.
Allow the foliage to remain on the plant when the four o'clock is done blooming for the season, as the foliage stores nutrition for the next year's growth. Remove the dead foliage in late winter or early spring.
Plant four o'clock s with care if you have young children, as all parts of the plant are poisonous. Keep four o'clock s under control as the plants can sometimes become invasive. Once the plants get started in an unwelcome spot, they are hard to remove because of the long tubers.