Four O’Clocks (Mirabilis jalapa), also known as the Marvel of Peru, are highly fragrant, trumpet-shaped flowers that open in the late afternoon. This tender perennial features a bushy growth habit and is often grown as an annual in cooler climates. Growing Four O’Clocks in containers offers practical advantages, allowing gardeners to control their spread and enjoy their sweet, evening scent on a patio or balcony. Container gardening provides easy mobility, letting you move the plant for evening enjoyment or to protect it from cold snaps. This method also ensures the plant receives the specific, well-drained environment it prefers.
Preparing Seeds and Container Supplies
Four O’Clock seeds have a hard, thick outer shell that inhibits water absorption and delays germination. To overcome this, use scarification, which involves lightly scratching or nicking the seed coat. This can be done by gently rubbing the seeds with fine-grit sandpaper or carefully nicking the surface with a sharp knife, avoiding damage to the inner embryo. After scarification, soak the seeds in room-temperature water overnight (8 to 12 hours) to prepare them for germination.
Selecting the correct container is important because Mirabilis jalapa develops a large, tuberous root system. For a single mature plant, the pot should be large, ideally at least 10 liters or about 20 inches in diameter, to accommodate the mature size of up to three feet tall. The container must feature adequate drainage holes at the base to prevent waterlogging and root rot.
Choose a high-quality, sterile potting mix designed for containers, as dense garden soil compacts and hinders drainage. A suitable mixture is well-aerated and drains quickly while retaining some moisture. An effective blend uses three parts peat moss combined with one part perlite, or an alternative incorporating coconut coir, to ensure a light and loamy texture.
The Physical Planting Process
The timing for planting Four O’Clock seeds depends on your local climate. Generally, the seeds should be planted directly into their permanent outdoor containers after all danger of frost has passed in the spring. If you wish for earlier blooms, seeds can be started indoors six to eight weeks before the final expected frost date. When filling the chosen container, leave a space of about one inch between the surface of the soil and the rim of the pot to allow for watering without overflow.
For container planting, place the seeds at a shallow depth of approximately \(1/4\) to \(1/2\) inch (0.6 to 1.3 cm). Given the plant’s bushy nature, sow four to seven seeds per large container; these will be thinned later. Distribute the seeds evenly across the surface before covering them with the potting mix to the specified depth.
After placement, lightly tamp the soil surface over the seeds to ensure good contact with the medium. This gentle compression eliminates air pockets and helps anchor the seed for consistent moisture uptake. If starting indoors, using a biodegradable peat or coco pot simplifies later transplanting. This is important because the Four O’Clock’s long taproot is sensitive to disturbance.
Initial Care for Sprouting Seeds
Immediately following planting, the soil in the container requires thorough but gentle watering to settle the medium around the seeds and initiate germination. Use a watering can with a fine rose or a spray bottle to avoid displacing the shallowly planted seeds. The goal is to keep the soil consistently moist but never saturated or soggy, as excess water can cause the seeds to rot before they sprout.
For successful germination, the soil temperature should consistently be between 65°F and 75°F (18°C and 24°C); seeds should emerge within seven to fourteen days. Place the containers in full sun (at least six hours of direct sunlight daily). In extremely hot climates, partial shade, especially in the afternoon, is beneficial. Once the seedlings develop their second set of true leaves, thin them out to prevent overcrowding.
Select the strongest seedlings and carefully remove the others, keeping only two or three plants per large container. This spacing allows the remaining plants sufficient room for root and canopy development, leading to bushier growth and abundant flowers. If started indoors, young plants must be gradually acclimated to outdoor conditions over about seven days, a process known as hardening off. This involves placing the seedlings outside for increasing durations daily, preparing them for the stronger sun, wind, and temperature fluctuations.