Tips for Growing Irish Plants in North Central Texas
Luck of the Irish
By Steve Huddleston
Many Texans have Irish roots. After all, many Irish immigrated to Texas during the state’s early history. Today many Texans – whether of Irish ancestry or not – celebrate St. Patrick’s Day and all things Irish. Maybe you’d like to celebrate your Irish ancestry or love of Ireland by creating a little bit of Ireland in your own landscape. Even though north central Texas is a far cry from the Emerald Isle, we can grow some plants here that are native to Ireland.
Ajuga (Ajuga reptans)
This evergreen, perennial ground cover forms a ground-hugging rosette, grows two to six inches tall, and spreads up to a foot in all directions. It has spoon-shaped and dark or variegated foliage, depending on the cultivar. The species has dark green leaves with a purplish tint. The cultivar ‘Burgundy Glow’ has variegated foliage with pink highlights on new growth. ‘Black Scallop’ sports glossy, burgundy-black foliage, and ‘Chocolate Chip’ has chocolate-tinged, smaller leaves.
All ajuga varieties produce six- to ten-inch-tall spikes of blue flowers that rise above the attractive foliage in spring. The plant grows by stolons (above-ground stems) to form an attractive, matt-like ground cover. The plant is not particularly tolerant of foot traffic, though. Ajuga grows best in shade in moist, well-drained, organically-enriched soil. Avoid planting in wet, heavy soils and in areas that receive late-afternoon sun. Also avoid planting near lawns where it can escape a flower bed and establish itself in the lawn, where its spreading nature could cause removal problems.
Ajuga is susceptible to root knot nematodes in sandy soil and to soil-borne diseases. Ajuga looks great in shady courtyard gardens, between stepping stones, and under shade trees where the grass won’t grow. It would be especially pretty with spring-flowering bulbs such as daffodils or summer snowflake coming up through it.
Common Foxglove (Digitalis purpurea)
This native of Ireland is a cool-season plant that must be planted in fall in north central Texas and treated as an annual. It goes through the winter as an evergreen rosette and then sends up flowering spikes as tall as three to four feet that bloom in April and May. Plant in full sun in moist, well-drained garden soil that has been enriched with organic matter. In the spring, the spikes produce two- to six-inch-long, bell-shaped, dark rose-pink to purple flowers with purple and white spots.
The flowers attract hummingbirds. The leaves are a source of the drug digitalis and are highly poisonous. The tall spires of flowers provide striking color and form and look best toward the back of the flower bed. After the flowers have finished blooming, remove the plants because they have completed their life cycle and will soon die.
Mallow (Malva sylvestris)
This is, essentially, a dwarf hollyhock. It is a short-lived perennial, but it comes true from seed and will re-seed freely in your flower bed. It likes full sun and well-drained soil.
The popular cultivar ‘Zebrina’ grows three to four feet tall and only 18 to 24 inches wide. It blooms mid-summer to mid-fall and sports two-inch-wide lavender blossoms with reddish-violet streaks. Since butterflies and hummingbirds feast frequently on the two-toned flowers, this is a great plant for a butterfly garden as well as a cottage garden. Because of its height, place ‘Zebrina’ in the middle or at the back of a mixed border.
White Clover (Trifolium repens)
This is a three-leafed clover, or shamrock, that St. Patrick could very well have used to explain the doctrine of the Trinity to the Irish people. It is an herbaceous, mat-forming perennial that typically grows four inches tall and spreads twelve inches or more by stems that freely root along the ground at the nodes. It features trifoliate (three-parted), rich green leaves and white, globular, marble-sized flowers in late spring. It grows best in full sun to part shade and requires a medium amount of water.
The flowers are attractive to bees and have a sweet scent. It’s great fun to pluck the stems, use your thumbnail to perforate the stem near the tip, and insert another stem through the hole to create a chain of clover flowers. Although native to Ireland and other parts of Europe, white clover has naturalized throughout North America in lawns, fields and roadsides. It’s a nitrogen-fixing plant that is often used in crop rotation; it’s also a good forage plant for livestock. Many homeowners, however, regard it as a weed since it can form large mats in the lawn. However, white clover is sometimes added to grass seed for lawns or grassy areas for a “mixed” or meadow look or for areas where grass alone does not grow or cover well.
Yarrow (Achillea millefolium)
Yarrow is a mat-forming, upright perennial that spreads by underground stems called rhizomes. It was introduced from Europe to America in colonial times and has since escaped cultivation and naturalized along roadsides, fields, waste areas and lawns. Yarrow produces deeply-dissected, fern-like and aromatic foliage topped by stems of flattened, white flower heads that rise two to three feet tall and bloom during the summer.
Foliage has a spicy aroma that persists when used in dried arrangements. The stems of the species tend to flop over. The cultivars and hybrids of the species, however, have stronger stems that remain upright. The cultivars also have larger flowers that bloom in colors of pink, red, cream, yellow and bicolor pastels. These cultivars do very well in ornamental gardens. Yarrow grows best in dry to medium, well-drained, sandy loam soil in full sun. Yarrow looks good in cottage gardens, wild gardens, meadows and naturalized areas. They make good fresh-cut and dried flowers.
Obviously, north central Texas differs from the Emerald Isle in appearance and growing conditions, but you can create a bit of Ireland in your own landscape by incorporating these native Irish plants that do well in Texas. In doing so, you can celebrate perhaps not only your own Irish roots but also the Irish and their influence on Texas.