Plants to impress in English early summer gardens.

It does appear to us at this stage as if the seasons are early this year. Mind you, winter struck early and with a vengeance so it is only fair that spring should similarly make an early appearance. With that comes a sense of panic. Should Rhododendron Rubicon be flowering in mid September and will we have any rhodos left to flower during Festival? We have enough experience to know that these things tend to even out over time and if the flowering remains early, at least our nuttalliis and maddeniis will see us through. But it has had our thoughts turning to the plants that really impressed us in an early English summer. We may need to draw on these for future festivals.

Frilly large and pink - we can't grow herbaceous peonies here
Frilly large and pink – we can’t grow herbaceous peonies here

Herbaceous peonies (or paeonia). Big frilly, fluffy, pink herbaceous peonies. They look fantastic, they need staking to stop them falling over and they don’t grow in Taranaki. Apparently they do extremely well in Central Otago and they are happy in a continental climate (dry, cold winters and hot, dry summers – rather the antithesis of here). We just have to admire them when we travel. And they are another short term wonder where they look just fantastic but then have a rather long time “passing over” as we say.

Philadelphus, aka mock orange blossom. These we can and do grow though we don’t feature them as much as we saw in England. There are a wider range on the market there, including larger flowered forms and double forms. Facetiously, I would add they probably have forms with variegated leaves too. The Brits do love their variegated foliage and their yellow foliage. These affectations add colour and texture in their climate with its diffuse light whereas we shun them here where our unfiltered sunlight burns them. The philadelphus is known as the mock orange blossom, I assume, because of its wonderful fragrance. It makes a large deciduous shrub – most forms get to 3 metres if you don’t trim them.

Cornus kousa was great all round the country. It is the dogwood from China and Japan – a small tree with flat flowers favouring pink but can also come in shades of white, cream and green tinged. We have a nice pink flowered one in our garden though it is a little poorly these days. There were a whole range of different selections in the UK, including some very large flowered ones and some top pink forms. We need to have a closer look at kousa. The American dogwood species don’t do as well for us here (they get decimated by the puriri moth) but kousa is a different story.

In the perennials, the stand out plants were alliums, verbascums, astilbes and eryngiums. Alliums are onions, though ornamental onions in this case. Some forms put up wonderfully decorative large spheres of purple and I wanted them instantly. Alas these archetypical inclusions of the English summer border are not really any easier there than here and the bulbs are often bought in annually. What a wonderful feature plant they are, though. The famous Beth Chatto Gardens list no fewer than 21 different ornamental alliums in their 2009 mailorder list.

Tulbaghia are onion relatives. English gardeners love to amass what are called National Collections of each and every plant genus, often in private gardens. We visited one garden which proudly proclaimed itself as the holder of a number of national collections, including tulbaghia. Hah, declared Mark, commenting that he thought there were only a very few different tulbaghia species. He was right. They are a small plant family, modest in number and modest in appearance. And indeed the National Collection of tulbaghia was considerably more impressive on paper than in reality. But it did give Mark a new claim to add to his repertoire. He has since been heard to proclaim: “Ah. But I have seen the national tulbaghia collection.” We do grow tulbahia violacea here but truly it looks a little chive-like.

Verbascums put up tall spires of flowers, typically yellow or white, with a rosette of leaves at the base. Great Dixter used self seeded verbascum spires as a repeated flower motif throughout the garden so we felt we were in good company as we too have a large flowered yellow form which is a biennial through our rockery. But we only have two forms and there are more than that which we will be tracking down for summer displays. We have tried and lost the most impressive verbascum, a splendid grey felted rosette with an impressive flower spire. Time to try it again.

Miss Willmott achieves immortality - eryngium giganteum
Miss Willmott achieves immortality – eryngium giganteum

Eryngiums are sometimes called sea holly and are mostly somewhat prickly. We have a lovely blue form in our rockery and it was because one was planted too close to the pathway that I discovered they have phenomenally deep and sturdy taproots. It makes them difficult to move. Eryngiums were used widely in English gardens, being tolerant of dry. There is a large form of the plant, eryngium giganteum, now called Miss Willmott’s Ghost. Said Miss W was a fine gardener but possibly a cantankerous old biddy who was a law unto herself. Allegedly, she made a practice of secretly scattering seed of eryngium giganteum in gardens that she visited so that the large, silvery plants would rise, ghost-like, long after her visit. Apparently eryngiums will seed down and many are biennial so only last two years. All I can say is the one I have in our rockery is a deciduous perennial and it has never yet self seeded, though I would be pleased if it did.

Astilbes. I fell in love with astilbes and the national collection of these at Marwood Hill in Devon was worth looking at. Big fluffy plumes in shades of white, cream, pink and rusty reds, all happy in damp areas but also preferring some shade with our harsh sun here. We visited Hollards Garden in South Taranaki last weekend and noticed their dell held the promise of a good display of astilbes later in the season. We can grow them here in the north, but they just don’t like being built up in nursery conditions (weevils seem to sniff the pots out from afar and move in) so we need to be more organised and build them up in the garden, not the nursery.

We were greatly taken with aruncus as soon as we saw it. Aruncus is a rather like a giant creamy astilbe on Eastern European steroids, ideal for wild or natural gardens. It needs space, at least a metre and a half across. We fell out of love with it equally quickly when we realised it had a short season and its beautiful creamy plumes of flowers turned brown and hung on, so it just looked burned. We noticed Persicaria polymorpha filled the same niche and a skilled gardener confirmed that this plant passed over more gracefully.

The stand out beautiful garden plant was a grass at Beth Chattos. I have now lost the piece of paper where I wrote its name down but I am sure it was a stipa. It is rather academic anyway because if there is one plant group that we will never be allowed to import new family members into this country, it will be ornamental grasses. Oh, and the ornamental thistles which looked great. The most truly awful plant we saw was widely grown, though goodness knows why. It was a thoroughly nasty spirea. Clumping yellow leaves (may even have had some sort of variegation to make it worse) contrasting with a yukky mauve pink flower. It was a good argument for glyphosate.