We are Portulaca grandiflora, commonly known as Moss Rose. We are a low-growing, succulent annual plant prized for our vibrant, rose-like flowers that come in a dazzling array of colors including pink, red, yellow, orange, and white. Our foliage consists of fleshy, cylindrical leaves that store water, a key adaptation to our preferred hot and dry conditions. We are native to hot, sunny plains, which is why we thrive in the intense summer heat across much of the USA, from the arid Southwest to the humid Southeast.
Our most fundamental need is abundant sunlight. We require a minimum of 6-8 hours of direct, unfiltered sun daily to bloom profusely and maintain our compact form. Without it, we become leggy and produce fewer flowers. We are not fussy about soil quality, but we demand excellent drainage. We prefer sandy or gravelly soils and absolutely despise having our roots sit in waterlogged earth. While we are tolerant of poor soils, a slightly acidic to neutral pH is ideal. Our succulent nature makes us exceptionally heat-tolerant and perfect for rock gardens, containers, and sunny slopes.
We are very sensitive to cold, so please wait until all danger of frost has passed and the soil has warmed significantly in the spring before planting us outdoors. You can start our seeds indoors 8-10 weeks before the last frost date, but we germinate best with light, so simply press the seeds into the soil surface without covering them. When transplanting seedlings or nursery plants, space us 6-8 inches apart to allow for our spreading habit. Handle our delicate, succulent stems with care to avoid breakage. Water us in well after planting to help establish our root systems.
Once established, we are incredibly drought-tolerant. Our water-storing leaves allow us to withstand periods of dryness. The rule is to water us deeply but infrequently, only when the top inch of soil feels completely dry. Overwatering is the most common cause of our demise, as it leads to root rot and fungal diseases. We require very little fertilizer. In fact, too much nitrogen will encourage excessive leafy growth at the expense of our beautiful flowers. A single application of a balanced, slow-release fertilizer at planting time is often sufficient for our entire growing season.
We are famously low-maintenance. A key practice is deadheading, or removing spent flowers. This encourages us to produce more blooms instead of putting energy into seed production. While generally pest-resistant, we can occasionally be bothered by aphids, which can be dislodged with a strong spray of water. The primary disease to watch for is stem or root rot caused by excessive moisture and poor drainage. Ensuring we are planted in the correct soil and watered appropriately will prevent most problems. We will happily self-seed in the garden if spent flowers are left on the plant at the end of the season.
