Saturday, May 23, 2009

Ajuga: A Low Maintenance Ground Cover

Ajuga (Ajuga reptans) is also known as Bugleweed because the flowers on its 6” tall spike are two-lipped and tubular. Flowers are generally in hues of blue and purple but can be found in white and red. It is an evergreen plant prized for its dynamic color that stays compact and thick year round. The oval glossy leaves are 3”-4” long and grow opposite each other in rosettes. The foliage has color schemes from dark green to bronze to purple and there are many variegated forms. They start blooming in early spring, peak in late May/early June and are done by the end of July.

Originally found in Europe and Asia, it thrives in full sun to full shade areas. However, if you plant it in full sun, the leaves will be smaller, but you’ll have more spikes and flowers. If it’s in the shade, expect bigger leaves and less spikes throughout the blooming season. Regardless of where you put it, this plant cannot tolerate salinity in the soil or drought. Though ajuga prefers slightly moist soil, it is very important that the soil be allowed to dry between waterings.

Ajuga is mature at 3.5” high but it can grow up to 9” in full bloom. It grows in Zones 3-9 and is frost hardy.

Ajuga grows best in moist fine or medium textured soil. A pH between 4.5 and 6.5 is ideal. Ajuga needs fertile soil so it would be best to incorporate composting or fertilizer before planting. It prefers sandy soil, but as long as the soil is well drained Ajuga will tolerate clay.

Like any plant in the mint family, it grows rapidly and spreads through rhizomes, which makes it a widely known and versatile border and ground cover. Seriously, it looks like a carpet and grows on slopes, so if you’re looking for a way to stop mild erosion this is it. If you’re planting it along your sidewalk to make your path lush, it will do the trick, but be prepared to trim it back frequently. Don’t use it as an edging for your yard- it spreads.

Ajuga is relatively cheaper than other ground covers simply because you’ll need less of it to cover the same square-foot area. If you buy them already established, plant them at least a foot apart.

Bumblebees and hummingbirds like them, but deer don’t. Ajuga is a low allergen.

Propagate these plants through division in the fall or spring every other year. Runners are easily separated from the original plant and replanted. Even if you don’t want to replant the runners, thin the mother plant anyway. It helps keep the plant contained. If you have a variegated plant and your runner has non-variegated leaves, pluck the runner out or it will revert to its non-variegated form. You can prune Ajuga with shears or just run it over with a lawn mower; it won’t be bothered either way.

Poorly drained soils and poor air circulation are the cause of most of Ajuga's problems.  Southern blight and fungal leaf spots are two.  If your plant gets blight or leaf spots, remove it and the soil around the crown immediately. Check other plants for signs of the fungus and trim or remove those too. Then wash your boots and tools. It may seem extreme, but prevention is the key to success. Plus, this plant grows so fast anyway you’ll hardly notice the absence of the ones removed. They are susceptible to root rot if you put soil above (or on) Ajuga’s crown or if you plant them too deeply. Just be attentive. They can also get crown rot if you don’t thin them out every 3 years or so.

To sum up, Bugleweed likes:
  • Any amount of shade or sun
  • Any well drained moderately fertile soil
  • Slightly moist soil that is allowed to dry between waterings
  • Air circulation around the roots
  • Occasional thinning
  • A pH between 4 and 7
  • Zones 3-9

Any of the following varieties could be perfect for your yard!
  • A. reptans x ‘Burgundy Glow’- 6” tall blue blossoms grow from 6” tall green, pink and cream speckled foliage. Expect bronze and burgundy tones in the winter. Plant 10” apart and expect a spread up to 18”.
  • A. reptans x ‘Catlin’s Giant’- One of the largest varieties with 4” blue spikes on 6” tall foliage with a 2’ spread. It’s green, bronze and ruddy leaves are as large as spinach and don’t tolerate foot traffic.
  • A. reptans x ‘Chocolate Chip’- Gorgeous green and chocolate foliage in the spring looks like a Hershey bar in the fall (if growing in the sun). A shorter varietal, it grows 4” tall and produces a 4” blue spike. It has an 18” spread and should be planted 9” apart. It’s narrow leaves look stunning en masse.
  • A. reptans x ‘Gaiety’- A happy little plant with 2” long purple and bronze leaves with 2” lilac flower spikes. Grows 8” tall, including the blooms, in Zones 4-8.
  • A. reptans x ‘Silver Queen’- Features 6” tall mottled light green and cream foliage and 6” tall blue whorled spikes.
  • A. reptans x ‘Metallica Crispa’- Its 5” tall deep bronze foliage looks most metallic in full sun. Sports a variety of blue 6” spikes. Some people report this variety grows in Zone 10.

Unlike other perennials, Ajuga is prized for its palette of colors that please the eye throughout the year. In addition to being a dense tough plant that can handle children, animals and the occasional car or bike, it easily turns that unplanted or forgotten part of the yard into a beautiful landscape you will be proud of.

You'll find a great selection of

1 comment:

Amy Maze said...

Thanks for this great info! I was thinking of transplanting some of the ajuga in my yard to an area that needs ground cover, but didn't know if it was a good idea (I don't know much about gardening). Sounds like it would be perfect from what you shared. Thank you!