Portulaca: A Welcome Self-Seeder

The annual known as Portulaca, or the Moss Rose, is typically such a prolific self-seeder, you just may begin to think of it as a “perennial”.

At a recent family function near a pretty swimming pool which was open late in the season, my cousin showed me three large mounds of Portulaca in mixed colors. The pool had a nice blue liner, helping the water look especially inviting on one of September’s sunniest days. And as a backdrop, these mounds of flowers looked amazing. Still in bloom even just before fall, these poolside beauties had served my cousin’s backyard very well all through summer.

I envisioned my cousin planting several good looking plants early in spring, tending them well, and reaping the reward of these lovely mounded displays at summer’s end. But when asked about this, he said, “No, I planted them a couple of years ago. They’re annuals, but they keep coming back.”

Now, when I talk of gardening, I often talk of my cousin. However, it is a different cousin who is usually in focus. My cousin with the Portulaca is another example of a family member who loves gardening. And he LOVES this succulent flowering plant that drops seeds in a fairly regulated area. I say this because although Portulaca is known to spread, it has in no way taken over my cousin’s garden. Instead, it has grown in purposeful mounds… no major spread across his whole yard, but a nice mounding growth that looks well planned.

Self-seeders can be interesting: What sows its own seeds for one person may not be the same “everlasting” investment for another. But I remember hearing the same praise for Portulaca long ago from my grandmother, who loved gardening but did not have stacks of dollars with which to replenish her garden each year. For matters of economics, she liked to focus on perennials, knowing they would return each year to fill her garden. But annual Portulaca was always on the tip of her tongue as a favorite plant. Apparently, the self-seeding nature of the plant worked for her, as the perennials did. These tropical looking plants with bright flowers comprised of flouncy petals gave my grandmother a lot of color-power fairly close to the ground. (The petals look almost as though they are cut from a single piece of silk, with a little ripple at their edges. And, oh… they are saturated with color.) Towering above the Portulaca mounds, my grandmother opted for tall flowering beauties such as Cannas. This created a summery display bursting in tones of yellow, orange, and pink… so pretty.

So, the Moss Rose, eh? What does it take to grow Portulaca well and become an admirer? Well, this easy-care plant loves bright sun for about six hours per day. It needs regular watering, but it wants well-draining soil that dries out quickly and thoroughly (think sandy or gravel-filled soil). And it likes a slightly acidic growing mix. Pets should not nibble at this succulent, as it contains calcium oxalates: Plant it in an area where they will not take notice of it.

Portulaca’s blooms fade and drop on their own, so it can be considered self-cleaning. And within the first growing season, it will set seed if left alone. If you are in a cooler region such as mine, you’ll let your plants sit undisturbed until frost comes. Portulaca will not survive the frost, but if you go light on the clean-up around it, the seeds will remain in place and do their thing.

If you live in a consistently balmy area, you don’t need to worry about terms such as “annual” and “perennial”: You lucky ducks, your growing season is indefinite. But if you are like me, living in a region where cold and frost put an end to summer gardening, then having some perennials and some self-seeding plants is a benefit, as they fill up the garden quite automatically.

No matter where you live, maybe there is time to sit outdoors, no jacket necessary, to enjoy one last summer sunset of the year. (Fall doesn’t arrive until tomorrow, after all.) But if your weather is like mine—rainy today, with seemingly no chance of an improvement—just know that if you have Portulaca gracing your garden now, it is likely to make an appearance next year—next gorgeous summer—if you do a gingerly clean-up and just let it do its thing.