No-one goes into horticulture expecting to earn a fortune. With the exception of a handful of high end garden designers, most gardeners, designers, botanists work in the industry for the love of it. Unless of course they happen to breed and licence a plant cultivar so successful it can be seen growing in every other garden, featuring in gardening magazines and mentioned in countless TV gardening shows. A plant for example like Salvia Amistad. Its vivid purple blooms on 1.2 metre high stems work just as well in cottage garden style planting as in exotic schemes and in the last few years it has proved a hugely popular garden stalwart.

At this stage of the story I’m imagining the man behind the Salvia Amistad phenomenon, Rolando Uria Professor of agronomy at the University of Buenos Aires, with a string of polo ponies and a luxury ranch in the Argentinian pampas, living happily ever after on the proceeds from worldwide sales of Amistad. The truth is probably far less glamorous. And the story behind Salvia Amistad is heartwarming. In 2005 Rolando spotted the plant at a plant show and began to propagate it. He was impressed that the purple flowers emerging from a darker, almost black calyx bloomed nonstop from spring to autumn. He shared his cuttings with friends at home and abroad giving rise to its name Salvia Amistad, or friendship sage. He went. on to licence the plant for commercial cultivation and in 2016 it was awarded the RHS Award of Garden Merit.

A fortnight ago I met one of Professor Uria’s friends, Oli Broom, head gardener at Southill Park in Bedfordshire, better known on Instagram as @the_sage_head. I was attending a salvia propagation workshop organised by WGFA, the Working for Gardeners Association. To say Oli is interested in salvias is an understatement. He himself holds plant breeders’ rights (PBRs) for 15 cultivars which are sold in 50 countries. His personal collection of 600 salvias is spread between his own garden, his mum’s garden and his allotment. 150 of them are in pots. And of course they feature heavily in the borders at Southill Park.

Starting with a general overview of salvias, we learnt that they grow naturally on most continents. The shrubby small-leaved salvias are the most resilient to drought, especially those from California and South Africa with the latter in particular able to tolerate winter wet and some winter cold. Some are more tender than others such as those from the Baja California peninsula in northwestern Mexico.

Oli led us on a tour of the gardens to the rear of the house concentrating in particular on the deep herbaceous borders which run the length of the Palladian style house. Salvias predominate in these borders, with one or two exceptions. Backed by the wisteria clothed orangery, the purple and blue themed border contains a host of treasures. Here the names of the various Salvia cultivars came thick and fast: Amistad, Super Trooper, Black Night. Oli pointed out a species Salvia macrophylla with its blue flowers and violet undersides to the leaves, the latter indicating its origins as an understorey plant in the forests of Colombia, Peru and Bolivia. Plants with purple undersides have adapted to catch light absorbed through the leaf and bounce it back to maximise light capture.

The small pale mauve and white flowers of Salvia leucantha had emerged only a few days earlier, shortly before the Autumn equinox. Oli explained this was an example of photoperiodism where flowering is influenced by day length. Some species of plants delay flowering until the day length is equal to or shorter than the night. In this case the plant is adapted to the average 12 hours of daylight in its home territory of Mexico. It came as no surprise when I checked later, that Salvia Phyllis Fancy which had just begun flowering at home, is a hybrid derived from this species.

We were shown the difference between the similarly sounding S. Animo and S. Amena. Animo is a blue form of S. Amistad with deep velvety blue flowers on tall stems. S. Amena, which is also known as S. Blue Butterflies has bright cobalt blue flowers on slightly shorter stems. The flowers of S. Cool blue are pale mauve and show up well at dusk.

More botanic facts emerged as the tour progressed: that members of this plant family (the mints: Lamiaceae) have square stems and that many species in their native environment are pollinated by hummingbirds.

The colours warmed as we walked along the border towards the middle of the rear elevation of the house. Named after his horse, Oli showed us the bright pink flowers of S. Jemima’s Gem which contrasted well with the deep purple flowers of nearby S. Nachtvlinder. It was interesting to see a Mediterranean salvia in this section: S. amplexicaulis with its purple spires on which I spotted a small blue butterfly. Other vivid pink flowered examples in this section were S. involucrata Hiley’s Form, a cultivar of the roseleaf sage from Mexico and S. Pink Pong. I was interested in the latter having propagated cuttings from a client’s garden a couple of years ago. I loved Oli’s story of the plant having originally been called ‘ping pong’ only for it to have been misspelt in the application for a PBR. Because its leaves are intensely scented, I think the pink pong moniker suits it admirably. I spotted another salvia that I grow at home: Pink Mulberry. I noticed this morning that it has started flowering again after a hiatus in September.

Although salvias predominate, there are a few other notable plants in this section. Two tall members of the mallow family stood out: Sphaeralcea with its open pale orange flowers and a scarlet flowered Anisodontea capensis, the cape mallow. We were intrigued by a Dahlia/Cosmos hybrid: Mexican Star with deep brownish red open flowers attractive to pollinators. The wealth of flowers in the border is balanced by some foliage plants including a paper mulberry with deeply lobed leaves: Broussonetia papyrifera.

The south facing border benefits from an irrigation system, hence its lushness after the exceptionally dry summer. The plants in these borders usually finish flowering around the first or second week of December, when Oli and his small team trim them back a little to prevent wind rock with a proper prune in spring. He has found that deer and rabbits avoid salvias, perhaps finding the scented leaves unpalatable.

Turning from the salvia border to explore the rest of the garden, we walked through a formal rose garden edged in box. The box is hanging on grimly but is showing signs of damage despite being sprayed five times a year. Oli would like to replace it eventually with a more resilient alternative. Several majestic Cedars of Lebanon and a well maintained ha-ha show Lancelot ‘Capability’ Brown’s involvement in the layout of the garden and park in the C18. The house and garden are surrounded by an estate of five tenanted farms. Native orchids thrive in less formal areas at a distance from the house. Southill Park is built on the Bedfordshire Greensand Ridge, the well-drained sandy soil being ideal for growing salvias. Oli showed us an open site where he would like to create a sunny scree area for about 300-400 Salvia species.

Classical statues near the ha-ha mark the entrance to a walk lined with rhododendrons, leading to an atmospheric sunken garden. This is a shady area with ferns, hostas, Solomon’s seal and toad lilies. We were all intrigued by the large scalloped leaves of a scrambling form of Salvia from Brazil, Salvia procurrens, which trailed down the stone walls of the garden bearing blue and white flowers. Further stone walls line a shady walk which is planted with blue Scilla and in spring resembles a river. The dry shade at the top of the wall sheltered S. forskaehli from Bulgaria and Turkey. The flowers had faded but Oli encouraged us to take a few seed heads. Our route back to the house passed alongside an extensive water garden where candelabra primula flower in early summer.

It was time to take cuttings from plants in the salvia border. Oli demonstrated taking non-flowering stems below a leaf node or removing the flower if necessary. He makes a diagonal cut at the base to create a larger surface area. He is in favour of sacrificing part of the mother plant for a decent cutting: the better the cutting the more successful the new plant. Ideally he takes 5 or 6 cuttings per plant. To avoid confusion later on, he labels as he goes along by loosely tying the cuttings together with garden string which he passes through the hole at the base of a plastic label before placing the cuttings into a container such as a travel mug a quarter filled with water.

We filled our travel mugs with cuttings and placed them in the glasshouse located within the kitchen garden at the far end of the house from the orangery. After a brief break for lunch we set to work to prepare the cuttings for planting. Oli starts off the cuttings in either prepared plugs or 9cm pots filled with a free draining potting compost. The medium he uses is a mix of well-riddled commercial compost, 25% sand and perlite or vermiculite. After trimming off the lower leaves and halving the surface area of the larger leafed specimens we were taught to dip the base of each cutting into Clonex, a rooting hormone gel, before placed them at the edge of the pot: up to 5 cuttings per pot. Those planted into the plugs we stood up in the flowerpots for support, about three per pot. Oli demonstrated his state of the art hydroponic propagator which enables him to take dozens of cuttings without using compost until the potting on stage after rooting. He sells many of the salvias he propagates at plant fairs around the country. Our more modest method of mimicking the warm moist conditions needed for the cuttings to strike was to place each pot into a clear plastic bag into which we breathed before loosely knotting them.

Before we headed off with our precious cuttings, Oli showed us some of the treasures in his collection: including a tiny Salvia from Namibia and some that are used as bases by perfumiers. Only two species of Salvia have scented flowers: it is usually the leaves that can be very strongly scented. I grow one called Blue Note which I just have to brush against to release its powerful fruity fragrance.

12 days on from the cuttings session I can report that all the cuttings I took appear to have taken. Those planted into plugs are showing healthy roots emerging from the plugs. In about 10 days’ time I shall pot them up individually and do my utmost to keep them alive over winter. Some should manage in my vertical cold frame but the more tender large-leaved plantlets will spend the winter on the kitchen windowsill. Here is a list of the salvias I chose:

• S. bicolor
• S. Heatwave Glimmer. This is a creamy white form.
• S. Jemima’s Gem
• S. Animo
• S. Amena, also called Blue Butterflies.
• S. Sagitatta

Oli’s enthusiasm for the garden he cares for and the salvias he cherishes is matched by his generosity in sharing it with lucky groups such as ours. He is about to embark upon a PhD to further his knowledge of the plant he is so passionate in growing and developing. I wish him every success with this and all his horticulture projects.

Kew Gardens 4 October 2026

Postscript

Southill House is the home of Mr and Mrs Charles Whitbread. The family’s origins in the brewing trade are evident in the old pub signs hanging in the meeting room where we convened on arrival at Southill.