Four O’Clock Care Must-Knows
Plant four o’clock in full sun and well-drained, evenly moist soil. Many varieties will tolerate part shade, but they then run the risk flopping over, thanks to this plant’s ultimate large size and fast growth pattern. Part-shade conditions may also lead to problems with powdery mildew. Four o’clock is extremely easy to start from seeds (it will even self-seed in optimum conditions). Soak them in water overnight before planting to improve their odds of germinating. Plant seeds directly in the garden soil after the last frost date, or start plants indoors 6 to 8 weeks ahead of that date. If you prefer to work with seedlings or transplants, plant them outside after the last frost date. Although often treated as an annual, four o’clock is actually a tender perennial that produces tuberous roots. It ultimately flowers better if grown from one of those tubers than from seed. That’s why you may want to dig up the roots in fall after frost has killed back the foliage. Wash the tubers, allow them to dry, and then store them in moist (but not wet) peat moss or sawdust in a cool, dry place until planting time the following spring. This is also the best option for varieties like ‘Limelight’ that won’t look the same if grown from seeds you save from the plant. Once the threat of frost has passed, you can plant the overwintered tubers outside again. First, turn the soil about 12 inches deep. Dig a hole that’s 1 inch deeper and two times bigger than the tuber. Place the tuber upright with its roots at the bottom of the hole. Fill the hole with soil, then tamp gently to remove air pockets. Soak with 1 inch of water, and keep the soil moist for about two weeks. Keep them well-hydrated as they grow.
More Varieties of Four O’Clock
‘Limelight’ Four O’Clock
Mirabilis ‘Limelight’ bears chartreuse foliage and bright magenta flowers on 2-foot-tall plants.
‘Red Glow’ Four O’Clock
This selection of Mirabilis bears vibrant red flowers on 2-foot-tall plants.
Four O’Clock Companion Plants
Cosmos
You can depend on this cottage-garden favorite to fill your garden with color all season long. The simple, daisylike flowers appear in cheery shades on tall stems that are great for cutting. The lacy foliage makes a great backdrop for shorter plants, as well. Cosmos often self-seeds in the garden, so you may only have to plant it once, though the colors can appear muddy or odd in the reseeders. Plant cosmos from seed directly in the ground in spring. Or start from established seedlings. This flower doesn’t like fertilizing or conditions that are too rich, which causes the foliage to be large and lush but with fewer blooms. It does best with average moisture but will tolerate drought.
Flowering Tobacco
Many types of nicotiana are terrifically fragrant (especially at night) and are wonderful in attracting hummingbirds as well as fascinating hummingbird moths. There are several types of nicotiana, also called flowering tobacco because it’s a cousin of the regular tobacco plant. Try the shorter, more colorful types in containers or the front of beds or borders. The taller, white-only types, which can reach 5 feet, are dramatic in the back of borders. And they’re ideal for night gardens; they’re usually most fragrant at dusk. These plants do best in full sun and moist, well-drained soil, and they may reseed.
Petunia
Petunias are failproof favorites for gardeners everywhere. They are vigorous growers and prolific bloomers from midspring through late fall. Color choices are nearly limitless, with some sporting beautiful veining and intriguing colors. Many varieties are sweetly fragrant (sniff blooms in the garden center to be sure). Some also tout themselves as “weatherproof,” which means that the flowers don’t close up when water is splashed on them. Wave petunias have made this plant even more popular. Reaching up to 4 feet long, it’s great as a groundcover or when cascading from window boxes and pots. All petunias do best and grow more bushy and full if you pinch or cut them back by one- to two-thirds in midsummer.
