Soapwort got its name because it was once used to make soap, particularly laundry soap. In addition to being a useful plant, soapwort is an easy, beautiful groundcover to grow in your garden as well.
Growing Soapwort in Your Garden
Soapwort is a lovely perennial that's often grown as a groundcover. It's hardy in Zones three through nine, and is one of the most low-maintenance plants you can grow in your garden.
The one-inch diameter, star-shaped flowers bloom in white and pink, and grow on leafy stems. They have a light fragrance that some liken to clover and others say has a fruity undertone.
Where to Plant Soapwort: Light and Soil Requirements
Soapwort needs good drainage, but other than that, it's not fussy at all about soil type. It'll grow well in loam, sand, and even gravelly soil. It might struggle a bit in clay, especially if it's in an area that stays wet.
Saponaria grows best in full sun to light shade.
It can be difficult to find transplants, so your best option if you'd like to start growing soapwort is to start some transplants indoors from seed and plant them outside after your last spring frost, or to direct sow in the garden in spring, after the danger of frost has passed. Germination takes about three weeks, and the plants or seeds should be planted about a foot apart.
Watering and Fertilizing
Soapwort isn't too fussy, but make sure to keep it watered during extended dry conditions.
You don't really need to fertilize it, but if you're growing in especially sandy or rocky soil, an annual dose of fertilizer, applied in spring, will be all you need.
Soapwort should be deadheaded after bloom to encourage more flowering. You may also want to deadhead to keep it from getting too invasive, though if you want it to fill an area, you should leave some flowers so it'll self sow.
When it's finished blooming, it's a good idea to cut the stems back to about half their height. This keeps the plant looking neater as the season goes on, and it ensures that you snip off any errant flower heads that might self-sow.
Soapwort Pests and Diseases
True to its low-maintenance ways, soapwort doesn't really have pest or disease issues. Because its leaves and stems are toxic, animals don't bother eating it, and few insects are interested in the bitter, saponin-laced leaves.
There are two ways to propagate soapwort, and both are easy.
- Sowing Seed: Soapwort grows very easily from seed, even self-sowing reliably in the garden.
- Division: Soapwort spreads via creeping rhizomes. It's easy to divide the plant and transplant sections of it elsewhere in your garden.
Is Soapwort Invasive?
Soapwort can become an invasive problem if it makes its way into natural areas, such as meadows and woodlands. Because it self-sows so easily, it can become a bit of a pest in home gardens. To prevent this, deadhead the flowers before they can set seed.
Using Soapwort to Make Soap
It's simple and straightforward to make your own liquid soap with soapwort, and could be a fun DIY project to try.
- Harvest 12-15 stems and add them to a pan with a pint of water.
- Boil this mixture for 30 minutes, then cool it completely and strain the leaves and stems out of it.
- This liquid soap will keep for about a week and can be used in any way you'd use liquid soap. It's traditionally been used as a laundry soap. You can even add essential oils if you'd like it to be scented soap.
It's worth keeping in mind that some people have skin sensitivities when using soapwort, so test it on a small area of your arm or the back of your hand to make sure you don't have a reaction to it before using it.
There are several members of the Saponaria family that are commonly grown in gardens. Some are best as groundcovers, and others are perfect for rock gardens or growing on and over walls.
Common soapwort (Saponaria officinalis) grows to about a foot tall and at least that wide and blooms in white and pink. Another common name for it is "Bouncing Bet," "Bet" being an old-fashioned term for a washerwoman or laundress.
Tufted soapwort (Saponaria caespitosa) is a neat little alpine perennial that flowers in summer.. It forms rosettes of linear leaves, and thick clusters of flowers, supported by short stout stems. This graceful little plant is valuable for the rock garden. A sandy soil suits it best, and it endures fairly cold winters.
Adriatic soapwort (Saponaria calabrica) is a creeping hardy annual that grows six to nine inches high, and is covered with small pink blossoms all summer long.
Yellow Soapwort (Saponaria lutea) is a tiny soapwort, growing three to six inches high, with narrow leaves and a neat tufted habit. The pale yellow flowers (rare among soapworts) bloom in early summer.
Rock soapwort (Saponaria ocymoides) is a trailing rock plant, with prostrate stems and rosy flowers that bloom in early summer. It is perfect in dry rock gardens, where a trailing plant is desired, as its trailing branches can creep over the face of the rocks and become masses of rosy bloom. It is also excellent for old walls, and the seed should be sown in mossy gaps where a little soil has gathered. It thrives in ordinary soil, and is often a good dwarf border plant.
Good Companion Plants for Soapwort
There are several plants that look absolutely wonderful planted with soapwort, providing lots of interest in color and texture. Consider adding a couple of these plants to any bed in which you're growing soapwort:
- Shasta daisy
- Balloon flower
Soapwort makes a very nice addition to any location that has good drainage. If you live in a compatible zone, use it to add beauty and contrast to a rock garden, flower bed, or any area of your garden that could use some brightening up.