The Agapanthus inapertus, which are kept in pots for their late summer display, are slow. They take time to decide when they want to flower, making you wait until they are settled in, sometimes a year or more after planting, producing nothing but foliage in the meantime. They are sluggish when breaking dormancy, keeping you on edge as the spring burgeons around them whilst they wait for the warmth. Once they get away I start a weekly seaweed feed to encourage flower and impatiently part their strappy foliage to see if they are going to reward me, for it’s not until the longest day or so that they let you in on their plans.
When the tapered sheaths – pointed like skyward arrows – begin to ascend, I move them to the front of the house from the holding ground by the cold frames before the stems are long enough to be damaged. Anticipation continues throughout July, as the flowering growth slowly draws itself out well into August and up to the teetering point between the seasons.
Their height and poise is what is so miraculous about Agapanthus inapertus and the fact that they wait until the very last of summer to reward you. Through growing them I now find it hard to say quite why I avoided growing agapanthus until moving here. I had not had the luxury of uninterrupted light in the London garden, for they hate competition or overshadowing and as a family they are perhaps tainted for me by association. The sorry plants that you see in the dust of municipal parks on holiday, not exactly thriving, but soldiering on. Or the Fawlty Towers seaside feeling they conjure here in the UK. Being bathed in sun on our open, south-facing hillside, makes you ask questions of your palette and, indeed, your prejudices, so the agapanthus are something of a welcome reset.
I have a rule to be sensible and only grow what works here. Nothing so tender that it needs more than cursory attention to get it through a winter, plants that like the conditions and do not make me fight for their survival and a self-imposed restriction to not having too many pots. However, the steadiness of agapanthus makes them very good for pots and they will last for many years before showing you that they need division by throwing less flower. The time to divide A. inapertus is in the spring, as soon as they show new growth. New divisions are slow to settle, but a year or two will see them return to flower.
The evergreen species of agapanthus, the A. campanulatus of the Victorian conservatory are rarely cold-tolerant, but the deciduous species tend to be more so and it is selections of A. campanulatus or A. inapertus that do better here where we freeze in winter. In their native habitat, where the deciduous species grow in open grassland or on forest margins, the climate is winter dry and summer wet, so I emulate this and move my pots into the barn where they are watered maybe twice over the winter and where they are protected from the worst of winter. If planted in the ground, I would choose free draining soil with plenty of humus and cover the crowns in winter with a layer of straw or compost, as I might a dahlia that was being overwintered in situ.
Agapanthus inapertus are the only agapanthus I grow here. I favour them over the more rounded heads of A. campanulatus, their slenderness, height and the tubular flowers which accentuate their elegance. The first to flower here in the middle of August is A. inapertus subsp. hollandii ‘Sky’ (main image). It had just come into flower when I left for a fortnight in America and I thought I was sure to miss it in the extreme heat, but not at all. Well-named for its pure, sky-blue flowers, this selection has an RHS Award of Garden Merit with good reason. Now in its fourth week of flower and standing at shoulder height, it was joined last week by A.i. ‘Midnight Cascade’, the darkest of those I have. It is described as pure black if you are hunting it down, but it is actually the darkest reddish-blue which, in bright sunshine, registers darker. All agapanthus hate their foliage to be overshadowed and this is a plant that you need to have on its own and against a pale backdrop to appreciate its architecture.
Towering above them all and coming into flower latest over the bank holiday weekend is A.i.‘Icicle’, the most elegant of all, perhaps, with the slenderest and tallest of stems. As the flowerheads expand you see that each pale flower is a cool, dark blue at the tip, as if dipped in ink. All of these are very attractive to several species of bumble bee which, contrary to expectation, squeeze their way in and out of the flowers.
I have several more, basking in sunlight up by the cold frames and filling out their pots before they come to flower. ‘Black Magic’ and the indigo-blue and slightly shorter A. inapertus subsp. pendulus ‘Graskop’, which is set to rise to just 90cm. I guess this is the beginning of a collection and the ignition of a desire to now see them in the wild and truly understand where they like to live.
Words: Dan Pearson | Photographs: Huw Morgan
Published 3 September 2022