There are about 10 species of this member of the carrot family, though only two are widely cultivated by gardeners – Ammi majus and Ammi visnaga. These easy annuals are grown for their delicate, feathery foliage and white, umbel flowerheads. They are popular summer-flowering ‘fillers’, ideal for padding out gaps between perennials or for use as fast growing, emergency replacements for unexpected winter losses in the border.
Though very similar, there are subtle differences between the two species. Ammi majus has white, wispy flowerheads which create a light and airy texture, whereas Ammi visnaga has larger, chunkier, rounded flowerheads with a green tinge, particularly when immature.
Ammi is also known by the common names of bishop’s flower and bishop’s weed.
Soil pH
Position
Hardiness
We send our ammi out as 4cm young plants in spring. These can either be planted out straight into the garden (go for it if the weather is mild and you have well-draining soil) or potted up and grown on for a few weeks (advisable in harsh or very wet conditions).
Weave your ammi throughout beds and borders, using them to plug gaps or holes in the existing planting. A long tap root means they’re happier in the ground than in a container, though if you really want to have a go opt for the deepest pot you can find.
Pruning and Deadheading
No pruning required. Either remove to the compost heap when finished, or leave in place until spring to allow goldfinches to feed on the seedheads during winter.
Watering
Ammi in the ground should be given a good watering in on planting, followed by a thick layer of mulch to lock the moisture in (see next section for more on this). Water again a few more times in the coming weeks, after which its deep tap root should sustain it in all but the hottest, driest weather.
With its limited root run, ammi in a container requires regular watering throughout the growing season. To avoid overwatering, a good rule of thumb is to allow the top couple of centimetres to dry out between soakings. To check this, wiggle your finger down into the compost until you feel moisture. Be aware that in the height of summer containers can need watering every day, particularly those in full sun.
Feeding
On healthy, fertile soil, a mulch of well-rotted organic matter (i.e., a layer of leaf mould, manure, or garden compost applied to the soil around the plant) should provide more than enough nutrients for your ammi. This has the added benefit of suppressing weeds and locking in moisture. Make this the final stage of planting, after watering.
Container-grown plants are different as they rely solely on the gardener for nutrition. Get off to a flying start by making sure you use a good quality compost with slow-release granules mixed in. These generally provide nutrients for around 6 to 8 weeks, after which you’ll need to apply a balanced liquid feed every 2-3 weeks until the end of the growing season (i.e., September-ish).
Cold Protection
While ammi is hardy, it can still be damaged by harsh weather when young. If you garden in a frost pocket or northern part of the UK, either delay planting out until late spring/ early summer or protect new plantings with a cloche or fleece whenever a hard frost is forecast.
Pests and Diseases
Ammi is considered trouble free.
Ammi is best propagated by seed, sown directly into the soil to minimise root disturbance (something all members of the carrot family resent due to their tap roots).
This can be done in either autumn or spring. An autumn sowing is suitable for milder parts of the country and will result in bigger, tougher, earlier-flowering plants, though it’s worth noting that the seedlings may need protecting with a cloche or fleece in unusually harsh winter weather. A spring sowing is best if you live further north or are prone to very cold, wet winters. Look out for weed seeds beginning to germinate in the garden – a good indicator that the soil is warm enough to get sowing.
* Many plants carry Plant Breeders Rights and cannot be propagated for commercial purposes.