5 Crocosmia to grow for a range of colours
Updated: Sep 12, 2022
Crocosmia are effortlessly easy to grow herbaceous perennials that grow from a corm (similar to a bulb) and bulk up to form clumps and occasionally colonies within a few years.
Relatives of the Iris, in the botanical family of Iridaceae, these colourful plants originate from Eastern and Southern Africa. They are popularly known in the UK by the common name of Montbretia (and are infamous to some under this moniker). Elsewhere they are commonly known as Coppertips, which I quite like. Montbretia most appropriately refers to Crocosmia x crocosmiiflora, but is fairly commonly used in the UK to refer to all Crocosmia. Crocosmia x crocosmiiflora is particularly vigorous and bulks up quickly in gardens showing little or no respect to neighbouring plants in its quest for border domination. That said, it isn't a pernicious weed like a Bindweed (Calystegia and Convolvulus sp.) or underground runner like Japanese Knotweed (Reynoutria japonica (Syn. Fallopia japonica)), Mare's Tail (Hippuris vulgaris) or Ground Elder (Aegopodium podagraria), so I find it difficult to understand why some people are so against it.
Most Crocosmia are very hardy in temperate gardens with a handful of less robust species being the preserve of collectors only. They die back in winter to beneath ground level to return each spring with fresh green foliage. Personally, I have never protected any over the winter, but in particularly cold spots, it might benefit plants.
They are pretty forgiving in terms of growing conditions, with good flowering success being found in the sun or part-shade. They are summer-flowering, with most starting to flower in June, before coming into their own in July and flowering through to August-September. They do well in most soils as long as they do not get overly dry. In humus-rich, fertile and open soils they ‘bulk up’ more readily to form substantial colonies.
Plants can be divided in spring to provide more plants or help established groups from becoming overly congested. It is sensible to divide plants every 3-5 years to boost your populations and as an opportunity to improve the soil and work it over before replanting.
There are over 400 different named cultivars of Crocosmia available and by far the best book out there is ‘Crocosmia and Chasmanthe’ by Peter Goldbatt et al from the RHS Plant Collectors Guide series (pictured below).
While not many of us will ever aim to collect 400+ different cultivars, most have space and maybe even desire for two or more varieties in our gardens and it seems sensible to have a really good 'go-to' plant for each of the main colours available.
Here are 5 readily available varieties that are worth growing for their different colours.
1. RED - Crocosmia ‘Emberglow’ (Above)
By far the most widely grown red flowered Crocosmia is the variety ‘Lucifer’ (Pictured first in the article). It is an excellent, large plant for gardens and consistently performs well with bright red flowers. ‘Emberglow’ is readily available, but less commonly planted and for no good reason! It is a little shorter than the substantial Lucifer (1.2m+) at a compact and manageable 75cm or so. I like this form a lot! It flowers a little later than most reds and lasts a bit longer. It is also a richer-red than most - Perhaps best described as Vermilion Red and complementing the dark, purple-red stems very successfully. Just as easy to grow and much more suitable to the average modern domestic garden size than Lucifer is. One to try!