Planting Four O'Clock
Four O'Clock is a warm season flower in the Nyctaginaceae family. Getting the timing right is the difference between a strong stand and a disappointing one, so the windows below are given relative to your own last spring frost and first fall frost rather than a generic calendar date. Look up your local frost dates and count back or forward from there.
Four O'Clock is started indoors 4–6 weeks before your last spring frost date, giving seedlings a head start before they move outside.
Sow Four O'Clock directly into the garden 0–1 weeks after your last frost, once the soil has warmed.
Four O'Clock can be grown by direct sowing and starting indoors. Starting indoors gives the longest, most controlled season, while direct sowing is simplest where the season is long enough.
Spacing and Planting Depth
Give Four O'Clock room to mature. The figures below come from verified extension and seed-supplier data for typical varieties.
| Spacing in row | 12 inches |
|---|---|
| Row spacing | 18 inches |
| Plants per sq ft | 0.67 |
| Planting depth | 0.5 inches |
| Sun requirement | Full sun |
Days to Maturity
Four O'Clock reaches maturity in 60–80 days from transplant.
Four O'Clock is ready to harvest after about 70 days. Harvest before the first fall frost, which will end the plant's productive season.
Conditions and Care
As a warm-season flower, Four O'Clock needs warm soil and settled weather to thrive, and is set back or killed by frost. It is frost tender, so wait until all danger of frost has passed before planting out and harvest before the first fall frost.
Four O'Clock needs full sun — give it at least six hours of direct light a day for the best growth and flavor. Sow seed about 0.5 inches deep, then keep the soil evenly moist until seedlings establish.
Four O'Clock belongs to the Nyctaginaceae family; rotating where you grow members of this family each year helps limit the build-up of soil-borne pests and disease. Four O'Clock is generally grown as a single planting each season rather than succession sown.
Growing Notes
Evening-opening flowers; can act as a Japanese beetle trap crop.