Plant taxonomy classifies yellow alyssum flowers as Aurinia saxatilis (sometimes given as Aurinia saxatile). Occasionally, you will still see the older classification, Alyssum saxatile. The cultivar 'Compacta' bears the common names, "Basket-of-Gold" and "Dwarf Goldentuft." The name 'Compacta' signifies that the cultivar stays smaller than the species plant. This genus belongs to the mustard family of plants (Brassicaceae).
Unlike the annual alyssum plants (Lobularia maritima) widely sold at garden centers (sometimes called "sweet alyssum") and commonly used as white bedding plants, yellow alyssum flowers are herbaceous perennials.
Characteristics of This Perennial
These perennial alyssum plants have a spreading habit and will put out clusters of small yellow flowers on upright stalks in April or May (depending on where you live). The leaves are also attractive, being a blue-gray color. The species plant reaches at most 1 foot in height, with a spread of 18 inches (the 'Compacta' cultivar will often reach only 8 inches tall with a spread of 12 inches). It reseeds itself readily and spreads to form a dense mat, making it an effective ground cover. It is reported to have naturalized in parts of New England (US).
The outstanding feature of this perennial undoubtedly is its impressive floral display, as it blooms in masses in spring. Do not, however, expect a nice fragrance from this plant; in fact, the flowers are quite bad-smelling.
Sun and Soil Requirements, USDA Plant Hardiness Zones
Yellow alyssum flowers are commonly grown in zones 3-7. They can be grown in zones 8-10 but will be short-lived there.
Uses in Landscape Design, Care for Yellow Alyssum Flowers
Yellow alyssum flowers are popular as ground covers for border plantings and for rock gardens. In rock gardens, their foliage will cascade nicely over the rocks. They are also a traditional choice for cottage gardens.
After the blooms fade, cut back these perennial alyssum plants by 1/3 to promote reblooming. Likewise, cut them back by 1/3 if they begin to get too leggy. Divide the plants in fall if you wish to propagate them (but this is usually an optional care task). Fortunately, these are deer-resistant perennials, so you do not have to worry about protecting them from Bambi.
Similar Perennial Plants, Origin of the Common Name of "Madworts"
Alyssum idaeum is a very similar perennial alyssum plant and also used in rock gardens. However, Aurinia saxatilis is much more popular.
Both Alyssum idaeum and Aurinia saxatilis are sometimes referred to as "madworts." The suffix, "-wort" simply meant "plant" in Middle English. But what could these plants possibly have to do with madness? Well, it turns out that they were used in folk medicine — where they were regarded as antidotes to rabies.
The origin of the botanical name is much more straightforward:
- Aurinia derives from the Latin word, aureus, which means "golden." It refers to the color of this perennial's flowers.
- Meanwhile, saxatilis is also from Latin and indicates that this plant "lives among the rocks," a reference to its natural habitat in its native Europe where it is found growing on rocky hillsides.