Happy Saint Swithun's Day
There’s a traditional poem that goes:
St Swithun's day if thou dost rain
For forty days it will remain
St Swithun's day if thou be fair
For forty days 'twill rain nae mare.
So from today, the 15th July, St Swithun’s Day until 24th August, it’s either going to chuck it down non-stop, or we’re in for a drought.
Legend has it that Swithun, a first century Bishop of Winchester asked to be buried in a simple tomb outside - ‘where the sweet rain of heaven may fall upon my grave’ – rather than within the Cathedral. His wish was granted until some years later when his remains were moved inside. Then the heavens opened and it rained … and rained … and rained… which gave rise to the saying about 40 days of weather.
How likely is it that it will be rain – or indeed stay fine – for that length of time? According to weather records which have been kept since 1861, it’s highly unlikely: there hasn’t been a record of 40 consecutive wet or dry days from 15th July onwards since those records began.
Even so, it got me thinking about the two extremes and what plants could possibly cope with either of those scenarios. Here, then, are my top St Swithun’s Plants – 5 wet-tolerant, and 5 drought-tolerant.
First the wet-tolerant, so we’re talking moist all the time with these.
My first plant that doesn’t mind moisture is Astilbe. Astilbe are actually one of the few perennial plants that actually thrive in shady and moist conditions. Some varieties will grow up to a metre with a spread of about 50cm, making a striking focal point and brightening up a dull, wet corner. I love the foamy sprays of flowers which are also good for cutting. I particularly like A. arendsii ‘Amethyst’ (pictured), introduced by German nurseryman Georg Arends in the early 20th century
My second plant that doesn’t need an umbrella is actually called the Umbrella Plant – it’s Darmera peltata. The umbrella bit relates to its leaves which can have a span of 45cm, and the plant itself can reach 1.5m, so you really do need a bit of room for this specimen. The architectural leaves can make a real statement in a bog garden, poorly drained areas or riparian locations, but it’s the flowers, which appear in late spring before the leaves that I particularly like. Each globe, atop stems of varying height, has clusters of star-shaped pink flowers – beautiful. Darmera will grow in full sun but most people seem to have better success in part-shade. Either way, the most important thing is to keep the soil moist.
Next comes Filipendula. F. ulmaria is the native meadowsweet or meadwort, referring to its use as a flavouring for mead or beer. My beekeeping friend makes mead but I have yet to persuade him to use some meadowsweet in it – in the past, meadowsweet was used for stomach complaints, so I don’t think it would do much harm. We’ll see. Other species of Filipendula have found their way into the garden, too: F. palmata (see picture) has lovely palmate leaves, and F. rubra, known as ‘Queen of the Prairies’, can cope with a drier environment. All species can cope with sun or part-shade.
My fourth plant is an Iris. Not the statuesque bearded iris which require free-draining soil and baking sun, no, this is Iris siberica which needs really moisture-retentive soil and can cope with part-shade. Although I. sibirica are clump-forming, they can multiply at a sometimes alarming rate if they feel at home: they will settle down and stretch out and before you know it they have occupied the space next to it that you had allocated for something else – in much the same way as our cat, Phoebe, takes up residence on the whole of the settee. Unlike bearded iris the falls and standards of I. sibirica flowers tend to be of the same colour, and the majority are blue, purple (like I. siberica ‘Percheron’, pictured), yellow, white and occasionally pink.
My final wet-tolerant plant is Zantedeschia. You have to be careful which species you choose, however, because not all can withstand the moist conditions that I’m forcing upon them. We need Z. aethiopica which - despite its appearance which makes it look as if it would be more at home in the tropics - is hardy throughout most of the UK, according to the RHS. I’m not going to argue with this because I used to grow Z. aethiopica ‘Green Goddess’ (pictured), which survived a Lancashire winter with very little attention. It will grow to about a metre in height with a spread of roughly 60cm, and can cope with sun or part-shade.
Well, that was the wet-feet brigade, let’s turn now to five plants that need just the opposite.
My first is Cistus. Hailing from dry, stony areas across the Mediterranean and the Canary Islands, these gems are drought-tolerant – in fact they need free-draining soil to thrive. There are over 20 species of this shrub but unfortunately, the majority of them are not hardy and will struggle in anything but a mild winter. You can easily take softwood cuttings from them in summer, however, keeping the plants in a frost-free spot over winter so you have some replacement plants just in case the parent plant doesn’t survive.
Plant them in full sun and you will have a beautiful display of open, single rose-like flowers (hence it’s common name of rock rose) all summer long. When they’ve finished flowering trim them back to keep a pleasing shape, but don’t prune them hard.
My second drought-tolerant plant is Dierama, or Angel’s fishing rods. Given its common name, many people assume that it actually prefers a water-side location with damp conditions. Nothing could be further from the truth – give it that sort of environment and it will mope and before long give up the ghost. Having said that, when I came across Dierama looking the best I’d ever seen it, it was growing in full sun alongside a min-water cascade – the important bit was that it was growing in almost rock-garden-like conditions with very free-draining soil. Soil is the key – that, and not disturbing them too much. Try and move them and they will sulk. This makes propagation a little tricky, as the only way to guarantee true offspring is by dividing the parent plant. You can grow Dierama from seed, but it is a little hit-and-miss as to what you will get and you will have to be patient because they will take at least three years before they are ready to flower. Far better is to buy a named cultivar from the garden centre nursery – some of the most spectacular introductions have been from Jim Cave in Cornwall, with his varieties named after Camelot characters: D. ‘Merlin’, D. ‘Guinevere’ and D. ‘Lancelot’. Depending on the variety, they’ll grow up to 1.2m with a spread of about 50cm – imagine a large group with their pendulous flowers swaying in the breeze – heavenly.
Third comes Erigeron. In many ways Erigeron are early versions of Michaelmas daisies – they have similar daisy-like flowers with yellow centres and they are also good for pollinating insects. The picture is of E. ‘Sommerabend’ – see what I mean about Michaelmas daisies? Given the popularity of Michaelmas daisies, I’m surprised that Erigeron are not more widely grown. Perhaps it has something to do with its common name, Fleabane, which, less face it, has a less than attractive ring to it. However, as its common name implies it is valuable for repelling fleas and other unwanted insects – a virtue that is not in such great demand these days but proved to be very useful before the advent of insecticides. Like my other drought-tolerant plants it needs free-draining soil and sun. Growing to about 60cm with a spread of 45cm or so, it would fit in almost any garden given the right conditions.
Fourth is Eryngium. I think if you were to try and describe an Eryngium to someone who had not seen one, and then went on to say that it is a popular garden plant, you would be looked at in amazement, nay, incredulity! Its thistle-y form and the almost surreal, electric-blue colour of the stems and flowers of some varieties almost defy description, and yet it has established itself as one of the stalwarts of the perennial border. This is perhaps partly due to the fact that there are a couple of British natives, including E. maritimum - from which we get the common name of sea holly - which have been cultivated over the years. The common name sea holly tells us the sort of conditions it likes – very free-draining, almost sand-like soil.
There are dozens of different species of Eryngium - all are spectacular in their own way, but I particularly like E. x bourgatii ‘Picos Amethyst’ (pictured).
Finally, there is Phlomis. I do think Phlomis is one of the unsung heroes of the perennial border. They’re statuesque, have an interesting form, provide whorls of blooms throughout the summer and, if you leave the tidying up until spring, you benefit from the faded, but still attractive, stems during the winter. They’re drought-tolerant, love a sunny position and are pretty-well trouble-free – oh, and bees love them too. I don’t think we need many more reasons to grow them.
So there we have my St. Swithun’s Day hit parade. I have a feeling that we’ll actually need plants that fall somewhere between to two extremes of wet and dry – but that’s for another blog post.