Although grown more for the texture and color of their leaves than for their flowers, lamb's ears do occasionally produce flowers on tall spikes (they bloom in late June in a zone-5 garden). Some growers find the flower stalks gangly. If that is your opinion of them, then just prune them off rather avoiding growing the plants. They are tough plants with a variety of uses.
Botany of Lamb's Ears
Plant taxonomy classifies lamb's ears as Stachys byzantina. The common name serves as both the singular and the plural form. We sometimes say "lamb's ear plant," but that's less descriptive, since, after all, this perennial favorite does have more than one "ear" (leaf). Stachys byzantina plants are classified as herbaceous perennials.
The plant's texture can best be described as "fuzzy" or "velvety." When we speak of "texture" in landscape design, we are usually referring to contrasting leaf forms. But the foliage of lamb's ears has an interesting "texture" in the more usual sense of that term. Upon seeing the foliage, you are tempted to reach out and stroke it.
Lending further interest to the foliage is its silvery color. The flower spikes reach 12 to 18 inches in height, but the rest of the plant stays much closer to the ground and has a spread of about 1 foot. Flower color is most typically light purple.
Some beginners to plant identification confuse this perennial with common mullein (Verbascum thapsus), another plant with silver leaves and a tall flower spike. But common mullein's flowers are a different color (usually yellow). This Old World native has naturalized in much of the New World; it is a common roadside weed in regions such as New England.
Planting Zones, Sun and Soil Needs
Lamb's ear plants can be grown in planting zones 4 to 7.
Grow lamb's ears in full sun in northerly climes. In desert areas, though, it can profit from partial shade. This perennial flower thrives in poor soil that is well-drained and has a slightly acidic soil pH. Treat it as you would any plant (many herbs fall into this category) associated with a Mediterranean climate. They are drought-tolerant in the North: you will lose some of the older leaves during dry spells (they brown up and look quite unsightly, so remove them), but the plant itself will survive.
Uses in Landscape Design, How to Control Its Spread
The plants are widely used in flower borders. They spread readily, making them effective ground covers for sunny areas if you do not mind them taking over. If you wish to start a new patch of them somewhere else, either dig up the new plants created through self-seeding or divide in spring. As drought-tolerant perennials, they are candidates for rock gardens. Their silvery color is fun to play with when experimenting with color theory in your landscape design. The plants are also deer-resistant and rabbit-proof.
Indigenous to parts of the Middle East, lamb's ears are considered invasive plants in parts of North America. They spread both by self-seeding and through creeping stems that root wherever they make contact with the soil. If you wish to control them, deadheading will address the former, but not the latter, which you will have to control with some type of edging.
Care for Lamb's Ears
Avoid watering the plants overhead, as the leaves will rot if they get too wet. For the same reason, avoid crowding to promote sufficient air circulation. Keeping them off the damp ground, likewise, is a good idea: mulch around them to accomplish this. A problem with this ground cover is that it dislikes humid conditions, in which it is susceptible to leaf diseases. Its saving grace in such cases, though, is that, because it spreads so readily, you will usually have new plants with which to replace the old, rotted plants.
Origin of the Names
The common name is descriptive: Lamb's ears produces leaves with a shape similar to that of a real lamb's ears; they're also velvety soft, further lending themselves to the comparison. The first half of the scientific name is also descriptive. The genus name, Stachys, is Greek for "an ear of grain," referring to the shape of the flower spikes. The species name, byzantina, refers to the plant's Middle Eastern origin, including an area that was once part of the Byzantine Empire.
Examples of Cultivars, Other Species
The Stachys genus has many species, byzantina being just one. A common name often used for the genus is "betony." Stachys byzantina, sometimes called "wooly betony," comes in a few different cultivars:
- Big Ears is a popular cultivar partly because it has just that: bigger ears than the standard type. And those who grow lamb's ears only for the foliage will be glad to know that this cultivar sometimes goes years without blooming. It also has better disease-resistance.
- Another cultivar that does not flower often is Silver Carpet. Staying short at 4 to 6 inches high, with a spread of 9 to 18 inches, its dimensions suit it to use as a ground cover.
- Cotton Boll gets its name from the fuzzy formations on its flower stalks where flowers should emerge but often do not, leaving gardeners, instead, with much more interesting-looking cotton bolls.
Silvery, fuzzy leaves are the signature of Stachys byzantina, but other species have green, smooth leaves. They are valued more for their flowers, which occur more regularly than on Stachys byzantina. Counting the height of the flower stalks, these plants reach about 2 feet tall, so they are not as suitable for ground covers as is Stachys byzantina:
- Stachys macrantha, "big betony," has purple flowers.
- Stachys officinalis, "wood betony," blooms in purple or white. It is considered an herb, having traditional medicinal uses.
Stachys officinalis alba (sometimes listed as Stachys densiflora alba or as Stachys officinalis Dwarf White) is the exception, in terms of size. It stands just 2 to 4 inches tall, with a spread of 18 inches. It has white flowers.