The September Garden 2022
I have to admit that every year I look forward to September and the start of autumn but this year following a very difficult summer for both gardens and gardeners I am looking forward to it even more, particularly after some very useful rain a few nights ago! September gardens are full of flower colour which is joined later in the month by the first signs of autumn leaf colour. September is also a great month for planting with its warm soils and hopefully increasing amounts of rainfall.
Here in west Wales our August garden has given Teresa and I great pleasure as always even though there has been a good deal of watering to be done in the greenhouse, pots, for the bonsai trees, on the vegetable plots and for any newly planted specimens. Established plants and the lawn are never watered and have to survive on their own which I am pleased to say they always seem to do. We have been very grateful for the water butts which we have been building up over the last few years and will try to find room for one or two more in the light of the drier summers which seem to be more likely in the future. I think that this summer has also been a useful reminder to us all about the sensible use of water in the garden. There is little point in simply splashing water onto foliage from which it evaporates very quickly and every point in directing water slowly, giving it time to sink in, to the base of plants at times of day when temperatures are lower. I read once that on most soils 1 inch of water will penetrate to a depth of around 9 inches which is exactly what plants roots need but this requires firstly a good amount of water, but importantly not very often, and secondly time for the water to infiltrate the soil rather than run off along the surface. Enough preaching I think so let’s move on to my plants of the month which are Japanese Anemones, Asters, Rudbeckias, and Grasses in general. I am also going to have a look at spring flowering bulbs which need to be planted between September and November and which have been arriving in garden centres over the last few weeks. Before I do so can I just bring your attention to a blog on the Old Railway site during August which looked at five great plants for helping bees in your garden– Buddleja, Scabious, Echinacea, Veronica and Penstemon, three of which I have featured this summer.
Japanese Anemones
The Anemone genus of around 120 species can be divided into three main groups, one of which comprises the larger herbaceous species which occur in moist, open woodland and grassy sites, which flower from late summer to autumn and are generally referred to as Japanese Anemones even though they come from various parts of Asia. This group includes Anemone x hybrida and A. hupehensis which both now contain a large number of cultivars which are excellent garden plants, for example A. hupehensis ‘Hadspen Abundance’, Bressingham Glow’,’Prinz Heinrich’, ’September Charm’ and A. x hybrida ‘Honorine Jobert’ (a beautiful single white with yellow stamens), ‘Queen Charlotte’, ‘Max Vogul’ and ‘Whirlwind’ (a semi-double white). Japanese Anemones are grown for their open, saucer or cup-shaped flowers with central bosses of usually yellow stamens. Most flowers come in various shades of pink but there are also some striking white flowered cultivars as I have already indicated. They do best in moist, fertile, humus-rich soils in sun or partial shade and can be propagated by division in either spring or autumn.
Asters
Asters are often referred to as ‘September Flowers’ so they had to have a place in my plants for this month. The genus is comprised of around 250 species of annuals, biennials, perennials and subshrubs from a variety of habitats in the northern hemisphere, particularly North America. However, recently the genus has been divided up by the powers that be into several new genera- all for the sake of correctness and simplicity! Some of our best known plants have remained in the Aster genus but others which are generally known as ‘Michaelmas Daisies’ which were Aster novi-belgii (New York Aster) and Aster novi-angliae (New England Aster) are now called Symphyotrichon, which I am sure you will agree rolls off the tongue so easily! I am sure you will see this new name on the plant labels but I also have a feeling that most nurseries and garden centres will still be using the old name for some time to come, I know I shall. Whatever they are called they still remain beautiful plants for the early autumn and although they may be considered a little old fashioned by some they are worthy of their place in the September garden with their numerous, daisy-like flowers with outer ray-florets in a variety of colours from white, through the whole range of pinks to lilacs, blues and purples and usually yellow inner disc-florets. Some of the older varieties can get quite large and are best for the back or middle of borders but some more recently introduced cultivars such as the ‘Island Series’ are much more compact and are suitable for the front of a border or even for pots. If your plants have suffered from powdery mildew in the past then it is worth avoiding the novi-belgii cultivars as they are more prone to the disease. There are so many species and cultivars to choose from but if I had to choose just one it would be Aster x frikartii ‘Monch’ which for some reason seems to have retained the Aster name. It has lovely, long-lasting, lavender-blue flower heads with orange centres held on strong stems up to 2ft or so high (60 cms) and as a bonus I have never known it to suffer from mildew. If you prefer the taller, older varieties and struggle to find them there is a wonderful garden and nursery near the Malvern Hills, the Picton Garden, which specialises in them and is certainly worth a visit in September or October if you are in the area. They may well do mail order if you have a look at their web site.
Rudbeckias- Coneflowers
This is a genus of about 20 species of annuals, biennials and perennials from moist meadows and light woodlands in North America. They are grown for their daisy-like flower heads, often with reflexed ray-florets and conical centres consisting of black, brown or green disc-florets, borne on long stems over a long period from summer to autumn. The best of the perennials is Rudbeckia fulgida and its best known cultivar is the very popular R. fulgida var. sullivantii ‘Goldsturm’ with its large, golden-yellow flower heads. Another excellent cultivar is R. fulgida var. deamii which is very free flowering with sunshine-yellow flowers and is slightly more drought resistant. Both plants are around 2ft (60cms) high but if you want a taller version the one to go for is R. ‘Herbstonne’ or ’Autumn Sun’ which is a giant of a daisy up to 6ft (1.8m) high with large, up to 5” (12cms) across, bright yellow flowers with conical centres. At the other end of the spectrum is R. hirta most cultivars of which have large, colourful, often two-toned flowers but are only around 1ft (30cms) high. These are generally grown from seed and treated as annuals in this country being less hardy than other Rudbeckias. Propagation of the perennials is by division in spring or autumn.
Ornamental Grasses
This is a group of plants which I still think are underrated by many gardeners but which can add a great deal to mixed borders, gravel gardens and prairie plantings. They may not be as colourful as other plants but their foliage and seed heads are attractive in their own right and their graceful movements in even the lightest of breezes and strong vertical lines make them a great addition to any garden. Grasses fall into two main groups – ‘Cool Season’ and ‘Warm Season’. The first group as the name suggests grow and produce their seed heads early in the growing season but as their foliage and seed heads remain attractive for many months they can still offer something to the late summer/early autumn garden. This group includes Carex, Festuca, Calamagrostis, Hakonechloa, Heliotrichon (Blue Oat) and most of the Stipas including Stipa gigantea (Giant Oat), S. tenuissima (Feather Grass) and S. arundinacea (Pheasant Tail Grass).
However, in the late summer it is the Warm Season grasses which steal the show as they flower at this later time. They generally prefer a sunny position but can tolerate less fertile soils. They are best seen against a darker background and when the sun is beyond them or to the side. This group includes- Cortaderia (Pampas Grass) eg. C. pumila, Miscanthus eg. M. sinensis ‘Zebrinus’ or ‘Morning Light’, Panicum eg. P. ‘Strictum’, Pennisetum (Fountain Grass) eg. P. alopecuroides ‘Hameln’ or ‘Little Bunny’.
In these monthly blogs and talks I generally look at plants which are looking good at that time, however, in the case of bulbs, and other underground food storage organs, it is a question of thinking ahead and September through to November is the time to plant bulbs to flower the following spring-‘Spring Bulbs’. A true bulb is essentially a very short stem with a growing point enclosed by thick, fleshy, modified leaves called scale leaves eg. Narcissus and Lilium. Other food storage organs are corms, tubers, rhizomes and stolons. A corm is the swollen, underground base of a solid stem as in Crocosmias and Gladioli. It stores food reserves and is surrounded by scale leaves which protect the corm. Bulbs and corms are often confused as they look similar but a major difference is that bulbs are made up of many fleshy scales whereas corms are solid structures. Corms also have much shorter life spans being replaced by a new corm that forms on top of the old one. Tubers are the swollen, enlarged, fleshy ends of an underground stem. They have ‘eyes’ comprising of a cluster of buds and a leaf scar which are the equivalent of nodes on a plant stem. Common garden tubers are potatoes, tuberous Begonias and Cyclamen. Sweet Potatoes and Dahlias also grow from tubers but these are root tubers without eyes and nodes rather than the stem tubers of the first group. Rhizomes are stems that grow horizontally along the soil surface or just below it. They are segmented with nodes and internodes from which leaves, shoots, roots, and flower buds develop. Ginger (Zingiber officinalis) and bearded Irises are good examples. Finally stolons are very similar to rhizomes with their horizontal stems on or just below the surface but unlike rhizomes they are not the main stem of the plant- they arise from a main stem and new plants are produced at the ends. When above ground these side stems are known as runners for example as in Strawberries. Some wild flowers spread themselves rapidly by runners and underground stolons eg. the creeping buttercup (Ranunculus repens). You may well be saying at this stage that all this is interesting but rather academic and I would tend to agree with you so for the purposes of the rest of this blog let’s just refer to them as ‘bulbous’ plants irrespective of their actual food storage organ. There is little doubt that spring, and in their own way summer , flowering bulbous plants bring a great deal to any garden or planting scheme .From the cheerful golden daffodil trumpeting the arrival of spring to the charming cyclamen, herald of the autumn, bulbous plants ring in the changes of the seasons with their glorious displays of flowers. Some also possess handsome foliage, others are valued for their fragrance but it is their blooms that make them essential for almost every garden. They offer a wide range of colour and form, from bright primary shades to delicate, pastel hues. They can be used to form bold patterns in a formal bed, fill in the detail in a mixed border, provide a splash of colour in a container or create sweeping carpets beneath trees or in grass bringing vitality to the more permanent plantings of the garden. Many of the bulbous plants in cultivation come from areas with a Mediterranean climate of hot, dry summers and mild, wet winters (but not as wet as Wales!) so require a well-drained soil in sun or part shade. Those which would normally grow in woodland thrive in moist, light shade and others like cyclamen can even tolerate dry shade under trees and shrubs. There are so many to choose from and everyone has their own personal preferences but mine are dwarf daffodils, snowdrops (Galanthus), bluebells (Hyacinthoides non-scripta), species crocus and tulips and fritillaries plus later in the season alliums. This year I am also going to plant some Camassia leichlinii for their wonderful spikes of blue flowers having been converted by seeing them at Aberglasney where they are used in the formal walled garden as well as in one of the meadows where they follow on from the Snakes’ Head Fritillaries. Apart from tulips all the above can be planted in September and October with the tulips following in November to avoid the dreaded tulip fire fungal disease which can be a problem if they are planted in soil which is still warm. The general rule of planting is to cover the bulbs to a depth of twice the height of the bulb but bulbs/corms/tubers bought in packets should l be clearly labelled with details of planting depth.
As for jobs for September the full list can be found in the archives for September 2019 and the jobs that we tend to do in our own garden are under September 2020. These include dividing perennials, planting spring bulbs, planting autumn and winter vegetables and repairing the lawn after the trials of the summer. Also in the archives for September 2021 are the details of our visit to the Aberglasney gardens for that month. They are always worth a visit at this time of year but if you can’t make it in person this month you can always have a look at the blog to see what you are missing.
I hope you will be able to join me for my free talk on Saturday 3rd of September at 9-30am in the Tea Room when I will be able to show off some of my favourite September plants and attempt to answer any questions which come up on the day.
In October the blog and talk on Saturday 1st will concentrate on trees and in particular fruit trees as part of the Old Railway Line’s celebration of trees. Until then stay well and happy gardening.
Keith.