Bells of Ireland Plant Profile

Not From Ireland but Still a St. Patrick's Day Favorite

moluccella laevis flowering in august

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Before green flowers became a hot trend, there were bells of Ireland, a flower in cultivation since the 1500s. Florists love bells of Ireland for their availability and longevity, and you’ll see them used in wedding flower arrangements as often as in St. Patrick’s day bouquets. As members of the Lamiaceae family, they are related to such ornamental and culinary plants as sage (Salvia), catmint (Nepeta), thyme (Thymus), and lavender (Lavandula).

Botanical Name Moluccella laevis
Common Names  Bells of Ireland, shell flower
Plant Type Annual
Mature Size Bells of Ireland stands 3 feet tall. The compact 'Pixie Bells' variety attains a height of 2 feet.
Sun Exposure Full sun to partial shade
Soil Type Well-drained, evenly moist
Soil pH 6.5 to 7.5
Bloom Time July to September
Flower Color White, but the green calyx is what is valued
Hardiness Zones Technically, 2 to 11, but plant performs better at northern end of that range
Native Area Turkey

How to Grow Bells of Ireland Plant

Bells of Ireland grow in all zones but fare poorly in areas with hot and humid summers. Shade cloth can go a long way towards prolonging the vigor of the plants when summer's heat kicks in.

Plant bells of Ireland in the garden after the last frost date in your area in average garden soil. Leave seeds uncovered, as they require light to germinate. The seeds are slow to germinate, taking up to a month to produce shoots, so for earlier blooms start them indoors two months before the average last frost date.

Stratification increases the germination rate of bells of Ireland. You can expose them to cold by sowing them outdoors in the fall, or by refrigerating them for a week before starting them indoors. Don't just place the seed packet in the refrigerator; for best results, combine moist conditions with cold temperatures to mimic an outdoor experience. Sandwich the seeds between moist coffee filters or paper towels in the refrigerator, followed by planting in soil. Experts say this moist stratification results in a higher germination rate than simply exposing dry seeds to cold temperatures. 

If you are lucky enough to find a well-stocked nursery with plugs or young plants, it's worth the extra money to start with these the first season. Doing this allows you to see if bells of Ireland grow well in your area without a significant investment of time or effort. If they take off, you can plant a bigger patch from the seed you save the following season. 

Bells of Ireland are top-heavy, and they may topple over after a heavy rain or in areas exposed to wind. Stake the blooming stalks, grow the compact variety, or grow them in a sheltered area to keep the spires upright.

Bells of Ireland don’t re-bloom, so you can remove plants past their prime without guilt. However, you may want to leave them in place long enough for the seeds to mature and scatter, as these annuals are self-sowing.

Light

Full sun is best. The plants need at least partial or morning sun to prevent them from flopping.

Soil

The plants like a soil that drains well and is kept evenly moist.

Water

Keep bells of Ireland consistently moist during the vulnerable seedling and transplant stages. Soaker hoses are great for providing moisture without water-logging the plants. 

Fertilizer

Bells of Ireland plant has just average fertility needs. Preparing the planting bed for them with compost should be enough.

Origin of the Names

The genus name, Moluccella, refers to the Molucca islands that were once thought to be the origin of the plants. The species name, laevis, refers to the smooth, hairless plant parts.

They are also commonly known as "shell flowers" due to their shape. But "bells of Ireland" is their chief common name because more people interpret the shape as bell-like. Whether you see them as shells or bells, be aware that the green color you're growing them for actually occurs in a calyx; the true flowers are tiny, white, fragrant, and hide within the calyx. Native to Turkey, not Ireland, their fresh green color and association with good luck (derived from their bell shape) give them the Irish part of their nickname.

Floral Designs With Bells of Ireland, Harvesting It

Bells of Ireland flowers are easy to dry, and they add interest to fresh-cut flower arrangements. The lime green flowers make an attractive foil for wine or magenta-colored flowers, like Red Velvet celosia (Celosia argentea 'Red Velvet'), globe amaranth (Gomphrena globosa), or Purple Prince zinnia (Zinnia 'Purple Prince'). 

If you harvest bells of Ireland for fresh or dried bouquets, wear gloves to protect your hands from the small spiny thorns that grow along the stems. This feature that keeps rabbits and deer away can also pierce your skin.

The stiff calyces of bells of Ireland last up to two weeks in fresh arrangements, but the flowers don’t maintain their green tint as dried specimens. The bells will gradually turn tan when they dry. For a fun bouquet twist, spray paint dried stems gold or silver and pair with fresh green stems.