In my last but one post I promised a virtual visit to Africa courtesy of three plants in my garden. Departure was delayed until the star performer came into flower. Diva like, she makes a spectacular entrance on stage, in this case the front garden which is a rather grand way to describe the space a metre or so deep between the bay window and the low wall beside the pavement. Here are three generous clumps of African lilies (Agapanthus africanus), which expand in volume each year. I described my passion for these southern African giants in a blog post a year ago. For nine months of the year the round ended strap leaves about 50cm long fill the space simply and elegantly. In late May flower stems emerge from the base of the foliage bearing plump pointy tipped buds, settling finally at a height at least half as high again as the leaves. At this stage I usually count the buds (26 this year) and compare notes with a friend who grows his front garden ‘Aggies’ in terracotta pots. One by one, the surface of the buds split, revealing dozens of pale sapphire gems which over the coming days escape the by now paper thin bracts to emerge as distinct flared petalled flowers in a pale blue with a navy stripe running along each petal. At last large blue spheres decorate each sturdy stem. And they need to be sturdy, to withstand my inching past them every evening to water the window boxes arranged around the bay.

A slighter Agapanthus cultivar whose name I do not know grows in several terracotta pots on the paved area at the end of the back garden. Unlike their evergreen cousins in the front garden, they die back each winter and I generally clear away the papery brown leaves in February by which time they part easily from the crown. Soon afterwards bright green leaf tips emerge from the tightly packed crown and at this stage I start to apply liquid seaweed feed every three or four weeks.

The front garden specimens self-seed enthusiastically into the plum slate which covers the little space left in the front garden around the African lilies. Throughout the year I extract them from the membrane beneath the slate, reduce the length of the roots by about a third and pot them up ready to be given away. A few weeks ago gardening clients contacted me to say they were keen to grow Alliums in their townhouse garden. I explained that the flowering season for most Alliums was coming to an end, but if it was tall sculptural plants with spherical inflorescences they were after then Agapanthus would fit the bill. Having stressed they would not flower this year, I was commissioned to plant the nine good sized clumps in a narrow bed alongside their large pond and in another very sunny flowerbed. I’m looking forward to seeing them develop over the next 12 months.

A friend came to tea in my garden a couple of weeks ago and observed ‘There’s a lot going on in this garden’ and she’s right. I have crammed a lot of plants into a small space both in pots and in the borders. The other African plants I want to share with you reside in containers. Having outgrown its original pot, earlier this year I split Cape figwort (Phygelius capensis) into three. They’ve developed into strong looking plants and I’m just waiting for their orange tubular flowers to appear. As the name suggests they are from South Africa. They remind me of Fuchsia ‘Thalia’ but are thankfully less tender and I can leave them outside all winter.

What I love about the next genus of southern African plants I want to share with you, Pelargonium, is their variety. Some grow upright, some trail. Some have scented leaves, some do not but make up for this with spectacular flowers. Some are chunky and robust, others, like velvety petalled P. sidoides are dainty and delicate. Carried on a long slim stem shooting out at a 90 degree angle from the crinkly three lobed leaves, are asymmetric umbels of four or five petal flowers in a shade of deep magenta. This plant is usually displayed in the Garden House in Mrs Child’s Flower Garden at Osterley. I bought one last autumn to use as a stock plant and repotted a couple of the leaf clusters, which were almost like runners, in gritty compost before overwintering them in the vertical cold frame. Now respectable sized plants, I have planted one in a large terracotta pot with another Osterley acquisition, Dianthus caryophyllus. On one of the last Osterley Fridays before lockdown when it was too wet to work in the garden, we spent a very pleasant afternoon in the new potting shed pricking out seedlings, including this ‘pink’. We were given permission to take the surplus seedlings to prick out at home. The fine greyish blue leaves already contrast well with the rounded leaves of the Pelargonium and I hope that when the dark red almost black Dianthus flowers appear they will complement the Pelargonium’s dark hued blooms.

My other Pelargoniums are less unusual, and can be categorised as annual bedding. I bought them as small plugs which were delivered in April. I chose both zonal and ivy-leaved cultivars, ‘Pink Passion’ and ‘Supreme White’ respectively. Both have pale pink flowers and I’ve planted them in the Ecopot window boxes I installed last summer. Like the Agapanthus, they relish the south facing aspect and I’ve blended them with two other southern African flowers, Felicia and Bacopa topia (Chaenostoma cordatum ‘Snowflake’).

There were other excess other seedlings to bring home from Osterley that day, several of which I pricked out and labelled (wrongly as it turned out) Rocky Mountain Columbine, Aquilegia coerulea. I began to realise my mistake when the true leaves developed into a pointed ovate shape and then the stem began to demonstrate distinctly climbing and clinging tendencies. For a while I thought I was nurturing some form of cucumber until today when by some wonderful serendipity, the first flowers emerged and I recognised it immediately as Black-eyed Susan, Thunbergia alata. a plant from Tropical Africa! It is one of the first flowers I grew myself when I made a container garden around the window of my first flat, a tiny studio in London. The flat was on the top floor of the building and a wooden ladder in front of the window led from the valley behind the parapet on the facade of the building to the top of the parapet. I trained a Thunbergia to grow up one side of the ladder and can remember being really happy at the effect I achieved.

I’m returning to Osterley next Friday, the gardens having reopened a couple of weeks ago, and shall be asking at what stage the seedlings I pricked out that winter’s afternoon were discovered to have been mis-labelled. More importantly though I shall be seeing the gardens, and some colleagues, after an absence of almost four months. I can’t wait.