Ajuga is one of the most common of perennial ground covers and with good reason. It is fast to grow, easy to grow, is quite hardy, attractive leaves and lovely blue flowers in the spring. What’s not to like about Bugleweed? Note that any plant that has “weed” as part of its name should come with a warning.
- Hardiness: USDA zone 3-9
- Sunlight: Shade to part shade to sun
- Bloomtime: Early Spring
- Bloom Color: Shades of Blue
- Propagation: Dig off a clump – division
- Leaf Color: Bronzes, Greens, Multicolor
- Planting Apart: 18″ centers
- Will Grow: 24-48″ wide
- Height: Leaves to 3-4 inches, flower to 12-inches on larger varieties
- Use: Ground Cover
- Special Note: This is a fast-growing, spreading thug
Ajuga ‘Sparkler’ from TerraNova
When Does It Bloom?
It blooms (normally with a deep, dark blue) in very early spring and sporadically thereafter. And you’ll see a range of foliage colours ranging from greens, to bronzes, multi-colours and almost purplish blacks.
Caution! Invasive Plant
Ajuga will invade nearby lawns and become a serious problem. We call it buglelawn. Forewarned is forearmed. Once it gets into a lawn, it is almost impossible to eradicate without using chemicals.
Yes, it is a spreader. But it spreads over the ground so you can (and should) contain it with a shovel by edging every spring and mid-summer. As a ground cover, I have found its spread to be slow but steady (but faster than you might think). This is comparison to other more aggressive ground covers such as goutweed that invade at the speed of light.
Ajuga ‘Toffee Chip’ from Terra Nova Nurseries
Light Levels Needed
This plant prefers light shade to full shade and tends to be smaller, shorter and less healthy in the full hot sun. And in an area that it likes, it will grow 2 to 5 inches tall (depending on variety) and spread to 12 to 18 inches or to the entire yard (whichever comes first).
Ajuga Blueberry Muffin TerraNova Nurseries
It grows well in average soil but will survive in soils with more clay or sand as major components. It will winter kill (rot) in heavy clay soils.
Given the above, if you want to see flowers you do have to provide adequate water when the plant is in the shade. This is particularly true when it is in competition with aggressive tree roots. This is not a plant for dry shade. Interestingly enough, there are gardener reports of this plant doing quite well in areas that are damp in spring and early summer but dry up for the fall.
It requires no special care. Put it in the ground, water for a few weeks to get it established and then let it alone.Some companies advertise it as being able to be walked on. I wouldn’t bet the farm on this; it might take a light walking over once or twice but it will not handle regular foot traffic.
Ajuga ‘Burgundy Glow’ a purplish leaf spreading ground cover for shade
The only Ajuga I’ve found to be a bit tricky is the multi-coloured foliage plants; they are not reliably hardy into USDA zone 4.
The only problem you’ll sometimes see with Ajuga is a little botrytis or grey mould. This will cause some leaves to shrivel up or flowers to abort. A fungicide spray with lime sulphur should stop this.
In spring, divide this plant and replant immediately.