The common names for the half hardy annual, and half hardy biennial Ammi include White lace flower, Large Bullwort, and Bishop's weed. Do not confuse with Queen Anne's Lace (Daucus carota).
They typically flower from late spring to early summer.
Ammi are medium sized plants that have white blooms carried on six inch wide (15 cm) umbel flower heads. Plants range in height from one to three feet (30 to 90 cm). Leaves are lance shaped. They make ideal plants for a wildflower garden.
Photo by Jacki-Dee.
The Ammi genus consists of six species and is a member of the ninety one genera of the Apiacaea family of plants; as such it is closely related to plants such as Anise, Cumin, Dill, Hemlock, Carrots and Fennel. It is a common feature for members of this plant family to have umbel (umbrella) like inflorescence's. Another common feature of the family is that the flowers have five sepals, five stamens and five petals.
Some of the common forms of Ammi are:
Bishop's weed, Large Bullwort, Laceflower, Greater Ammi (Ammi majus) - Annual
Toothpickweed (Ammi visnaga) - Biennial.
It is best to sow Ammi species such as Bishop weed on the soil surface then give them a light dusting of soil, with a spacing of 25 to 35 cm for smaller species and up to 100 cm apart for larger species in the early spring, before the last frost.
They can grow in light shade or full sunlight. The soil should be fertile and moist. Ammi requires between 1 and 4 weeks to germinate, if germinating indoors it is ideal to keep the temperature at 13 to 18 degrees Celsius. Grow them for seven or eight weeks before putting them out in the spring.
Ammi are is easy to look after, though they require watering in the dry spells of summer. Be aware that the sap of Ammi plants can be dangerous, do not get it on your skin as it can react with light and cause painful skin rashes.
Bishop's Weed, White Bishop's Lace (Ammi majus)
Varieties of this annual species of Ammi range in height from one to three feet (30 to 90cm). They should be planted from 12 to 15 inches (30 to 40 cm) apart in either partially shaded or in areas of full sunshine. Sow seeds outdoors directly after the last frost in your area. The plants will flower from mid summer through to early autumn with white blooms.