The dahlia is set to take centre degree in our borders and it’s going to clutch the limelight till the primary frost brings the curtain down – and at the present time that might imply November. No different flower will raise you via from summer season into past due autumn with as a lot pizzazz and vibrance.
Among the types, there are spiky cactus dahlias, which explode within the border like firecrackers, and prim and correct ball dahlias with comely ruffs of petals. There are mild water lily varieties, impressions from a Monet portray; fairly sharper decoratives; and bee-friendly singles and semi-doubles.
The Honka dahlias, which glance dismal in footage, are extremely efficient in a combined planting. Anne Barnard, of Rose Cottage Plants (see providers), tells me that ‘Honka Rose’ “looks as though someone has tossed a handful of pink stars into the air and they’ve landed where they fell”. The shade vary is similarly spectacular.
Compact dahlias make nice container crops. The Dark Angel Series combines small, unmarried plants and black, ferny foliage. Look out for ‘Star Wars’ (a yellow and orange); ‘Dracula’ (a dark-centred blood-red) and ‘Pulp Fiction’ (a better clear-red). The Happy Series of dahlias has higher unmarried plants on lengthy stems. My favorite is ‘HS Wink’, a raspberry-centred crimson.
Velvety reds incessantly have a marginally of darkish Guinness hues thrown in, and so they gained’t frazzle in scorching solar as such a lot of darkish plants do. There are comfortable peaches and pumpkin oranges that chime with mellow autumn days, and purples, pinks, lemons and whites. Sometimes the foliage is near-black, or army khaki.
The range of shape, foliage and flower shade in dahlias is because of an octoploid tendency – which has not anything to do with the ocean mattress. In simplistic phrases, the 40 or so Mexican species may have as much as 8 copies of the similar gene. When the bees get busy you by no means know what’s going to pop up from the parental gene financial institution.
This explains how the brilliant-red, peony-flowered ‘Bishop of Llandaff’ spawned a fully-petalled, bronze-orange seedling, due to this fact named ‘David Howard’.
Both are unbelievable performers, with actual endurance, and each have a capability to flower in deficient summers. Fergus Garret, head gardener at Great Dixter in East Sussex, favours ‘David Howard’ for its “show-stopping charm” within the borders. This megastar performer used to be raised in 1958 through the past due Suffolk nurseryman of the similar identify.
However, all that serendipity is a double-edged sword, as a result of there at the moment are such a lot of dahlias on be offering. New ones are repeatedly being raised and named through hobbyists and breeders. The cut-flower industry supplies a lot of the impetus, for dahlias are without equal cut-and-come-again flower.
Show bench dahlias, symmetrical charmers disbudded to provide large blooms, had been as soon as sized through passing the plants via a suite of rings. Many a excellent one landed at the slicing room ground, so that you can talk, however such is call for lately that that’s all modified.
The splendidly wispy whirligig christened ‘Waltzing Mathilda’, by no means a contender for appearing, fought for and gained an AGM at the RHS trial. The wild-looking, ferny foliage and ruffled, chrysanthemum-like blooms of ‘Soulman’, a wealthy burgundy, colour-washed in black, is every other stunner that wouldn’t win a display class both.
The downsides to dahlias
There are drawbacks. You can’t escape with plonking a dahlia right into a border, as a result of those past due starters best start to get into their stride as soon as the nights start to get longer and cooler. This short-day tendency is shared through many late-flowering perennials – salvias, cosmos, penstemons – however their pigment-packed petals create a jewel-box high quality that’s lacking previous within the 12 months.
Garret has the answer: “We create semi-permanent gaps, or bedding wallet, within the borders and fill them with spring bulbs and bedding. We incessantly use forget-me-nots and tulips. They’re got rid of in past due May after which our dahlias pass in.
“One of my favourites is the vivid-red ‘Witteman’s Superba’, a bold red cactus dahlia. It glows in front of a vertically striped green and cream grass, Miscanthus sinensis ‘Cosmopolitan’.”
Dedicated slicing gardens and allotments go well with dahlias neatly; I don’t stake mine, however planting taller cosmos and Verbena bonariensis amongst them is helping to supply strengthen.
There’s at all times a debate about whether or not to go away them within the flooring over iciness, or to boost them. I’m at the facet of lifting, after they’ve been frosted, as a result of I misplaced the lot in 2012.
However, huge tuber plenty defy common sense and bring much less flower, now not extra, so common department is wanted, even supposing there are exceptions. The man-high, rich-purple ‘Admiral Rawlings’ isn’t disturbed at Old Wollerton Hall in Shropshire – the place Leslie Jenkins peps up her colour-themed borders with dahlias.
I retailer mine below the greenhouse bench, in huge ethereal bread trays, and canopy the muddy tubers with dry compost. They keep there, frost-free, till March, after which they’re divided (if wanted) simply as they begin into expansion.
How to develop dahlias so they arrive up and flower annually
- Order your tubers within the New Year. Store them in a cool, frost-free position till mid-March and pot them, ideally in a greenhouse fitted with a heater to stay frost out.
- Once temperatures means 20C (70F) dahlias develop away enthusiastically. Pinching out the end of the shoots encourages bushiness and you’ll you utilize the snippets for cuttings (see underneath).
- Harden off dahlias outdoor, from mid-May onwards, however quilt with fleece if a frost is forecast. Don’t plant them outdoor till the start of June, as chilly nights test their expansion and a past due frost can kill them.
- Add a small handful of blood, fish and bone to the planting hollow after which observe one high-potash feed, equivalent to Vitax This autumn, on a damp day in June.
- Over-lavish feeding promotes foliage on the expense of flower.
- Once established, dahlias can live on with out being watered because of their tuberous roots.
- Dark-leaved dahlias are extra liable to slugs.
- Always deadhead to stay the plants coming.