Summer Perennials that Perform!

Ian and Teresa Moss, from Rare Plant Fairs, with a selection of less well-known summer flowering perennials that they recommend for your borders. - 12 July 2019

When we sit down and plan to write an article for the Rare Plant Fairs newsletters, we usually choose to focus on a particular plant family, and have written about (amongst others) hardy Geranium, Erodium and Echinacea in the past. But this approach tends to leave out many excellent perennials which we're happy to recommend, but which don't fit under a neat heading. So in this piece we're going to talk about a miscellany of perennials. a number not frequently seen, that we've grown in our own garden, which we really rate, and which we haven't shared with you before.

Nepeta

We've been starting to get a little bit hooked on Nepeta in recent years, and it could turn into another one of our obsessions if we had more room for them. Probably the most unusual and most striking variety that we've planted in the last couple of years is the excellent Nepeta nuda 'Romany Dusk'. Growing to about 150cm tall, it's an outstanding plant for the mid to back of border, with strong stems that are dark coloured and topped with pale pink flowers that are an absolute magnet for bees (as are all Nepeta). It's undoubtedly on of the stars in the garden in July and August.

Another excellent Nepeta is N. grandiflora 'Summer Magic'. A shorter growing plant than other varieties of grandiflora, it is compact and free flowering right through the summer, and grows to around 35 cm x 45 cm, and is great for edging paths, or combining with roses, hardy geraniums, lavender etc.

Finally, although we have mentioned this one before, we should also give another quick plug to the wonderful Nepeta 'Blue Dragon', with it's large blue flowers on stems to about 60cm. All the Nepeta do well in a sunny site in well drained soil for us.

Romneya coultheri

This is not a plant for the faint-hearted, but if you have the room and the nerve it is a truly spectacular plant for mid-summer. Ours is growing in a very sunny spot in well drained soil, and reaches around 200-240cm in height by the time it's in full flower. It has fantastic grey-green foliage and large white poppy-like flowers with an egg-yolk yellow eye. It does sucker a bit, but for us at least it's easily controlled, and it is a plant with a real wow factor.

Diplarrhenia moraea

This is a perennial that's not often seen in nurseries these days, but we have found it to be a very reliable performer. It hails from Tasmania in the wild, and has iris-like foliage with white flowers with a yellow and purple eye, to around 45cm. Very lovely and has proved reliably hardy with us.

Allium sphaerocephalon

It would be wrong to describe this as rare - bulbs are readily available in the autumn. But it certainly deserves to be more widely grown. This Allium grows to 90-120cm for us, and is a joy from the time the buds form right through to the seedhead stage. The flowers are a wonderful burgundy red and combine beautifully with the hot colours of mid to late summer perennials such as Echinacea, Kniphofia, Achillea etc. The trick to getting the best out of it is not to be mean with the bulbs; go for big large clumps and you'll be rewarded with a stunning show.

Verbena officinalis 'Bampton'

In our view this is about the best of the hardy Verbena for the garden. We have found it to be reliably hardy, given decent drainage, much more so than V. bonariensis or V. rigida. It's a lower growing variety, typically to about 45cm or so, and forms a neat compact plant with superb burgundy coloured foliage and lots of small and very pretty pink flowers. Like all Verbena, its a great plant for bees and butterflies. It does seed around a little, but not in an annoying way; after a couple of generations, however, you may start to lose the leaf colouration, so be rigorous about discarding any greenish seedlings that pop up. And the more sun you give it, the darker the leaves!

Althaea cannabina

This is another tall perennial, growing to about 180cm, with finely divided foliage and lavender-pink mallow-like flowers through the summer. It gives a light an airy feel to the border and it very pretty. . Unlike other members of the genus, this does not suffer at all from mildew, and enjoys full sun and a well drained soil.

Achillea ageratum 'Moonwalker'

We've been a bit delicate and pastel with our recommendations so far, so let's finish with a bit of zing. This Achillea is a selection of A. ageratum (English Mace), and has smaller flowers than selections of A. millefolium but lots of them. What we like about it most is that the flowers are set against a fabulous emerald green foliage, whereas a number of the yellow forms of A. millefoilium have a more greyish, silvery foliage that doesn't always complement the flower. It is reliable and easy, long flowering, and comes true from seed. What more could you want from a great summer perennial?

Ian and Teresa Moss are retired nursery owners and organisers of Rare Plant Fairs. But as obsessive, compulsive gardeners, you may occasionally find us at some Fairs selling the surplus plants (all interesting!) from our own propagation, mostly from our collection of over 150 salvias.