What to plant now for summer flowers, including dahlias, lilies and anemones

Telegraph

09-03-2025

Planting bulbs, corms and tubers now will add a blast of colour to your garden from June through to September, and they won't break the bank, because most have been field-grown in Holland. The key ingredient is water, because these somewhat shrivelled treasures need nature's moisturiser to rehydrate them. Most summer-flowering options won't be fully hardy, so they will be better started off in pots before being bedded out in late May or early June. A greenhouse or cold frame works best, but you can also place your potfuls in sheltered positions and fleece or bubble-wrap them on chilly nights.
Autumn and late-summer-flowering perennials are also available, and many of these will endure year after year. They will all add vibrant colour, because most hail from the southern hemisphere. Their pigment-packed petals are designed to withstand whatever the weather throws at them, be it strong sun or heavy rain. Many of them also cut well.
What to plant now
Gladioli
Underrated and underused, these offer weeks of flower and come in sumptuous shades, including lime green, plum purple, lilac mauve and peach melba. Just be sure to select a colour theme to avoid the gaudy dolly-mixture look redolent of Dame Edna Everage. Last year I interplanted my dahlia beds with clusters of gladioli and they supported each other brilliantly, with no time-consuming staking needed.
Favourites include the black-red 'Espresso', the lime-green 'Evergreen' and the DayGlo-like 'Bubblegum'. Make a hole about 10-15cm (4-6in) deep, because deeper planting helps to keep gladioli stems upright. Flowering will follow in 12 weeks or so. If you want to cut them, plant a few corms every two weeks between May and July so that you get a succession. If you want to stake, add the cane before you fill in the hole, so that you avoid damaging the corm. For containers, I'd recommend the subtler, more elegant and fragrant Abyssinian (or Acidanthera) and also the velvet-textured 'Ruby red'.
Anemones and ranunculus
If you're a cut-flower fan, plant breeders are producing lots of frilly-flowered and sturdy-stemmed new ranunculus in shades of golden yellow, mauve, purple, pink and cream. Their globular flowers, some with a picotee dark edge, appear in late spring and they're great in containers, or in good, moisture-retentive soil. After all, the buttercup family, or Ranunculaceae, is named after a genus of frog. You'll also find colourful anemones in rich blues, virginal whites and grenadier-guard red and they often display a deliciously dark-black middle. Or you may prefer Farmer Gracy's Galilee Pastel Mix, a nod to their Holy Land origins. Consequently, these anemones prefer good drainage.
Crocosmias
These sunbird-pollinated South African plants come in jaunty yellows, tomato reds and warm oranges, and most will flower in the second half of summer onwards. Plant in groups of three or five, so they produce a clump. I would avoid the over-robust 'Lucifer' in smaller gardens. Go for the lower-growing late-summer 'Firestarter' instead – it produces masses of orange-edged, rich-yellow flowers and it's always proved extremely hardy for me.
Elsewhere, 'Harlequin' has peachy buds that open to yellow, while 'George Davison' offers a taller, heritage golden-yellow iteration. The later-flowering 'Star of the East', raised by Davison in 1910, also features huge open flowers in burnt-sugar shades. Sadly, 'Emily Mackenzie' – a mahogany-red-eyed warm orange – is not hardy for me in the ground, but it's lovely in a pot. Keep them well watered, because crocosmias fail in dry summers.
Lilies
These are a variable group but they all offer a statuesque presence due to their whorled foliage and bold flowers, whether in pot or border. Martagons prefer a woodland edge or semi-shade, and hybrids include the burnished-red 'Claude Shride'. However, if you want heady fragrance on a summer's evening, seek out the paler-hued oriental lilies. 'Dizzy' has raspberry-ripple flowers with six white petals speckled and middled in pink.
Others include the white and gold-infused 'Mr Cas' and the ubiquitous all-white 'Casa Blanca'. Remember that lily pollen stains clothing though, so place the pots carefully. The more vivid lilies lack scent, but there are smouldering blacks such as 'Night Rider' and many dappled oranges and reds on offer too. Lily beetle seems less active in shadier spots, while 'King Solomon' is said to be beetle resistant (try Thompson & Morgan and Hayloft for this one).
Eucomis
Pineapple lilies have a tuft of bracts above a flowering spike, rising above substantial foliage – and some of them are deliciously scented too They are found naturally in the sunny meadows of South Africa, so they sulk in the shade; find them a sunny spot and they may come back next year if you're in a warmer county. Luckily, they look equally good in containers, so they can be taken under cover in winter and kept on the dry side.
'Sparkling Burgundy' bears pink starry flowers along a sultry stem, and the rich maroon curly-edged leaves add to the exotic look. The less showy Eucomis comosa has plain green leaves, but highly scented flowers in subtle shades of white, pink or honey brown.
Begonias
Lots of gardens are blessed with shadier spots and most of the colourful summer-flowering tuberous begonias are bred from South American species found in jungle-like situations. They combine colourful flowers and sumptuous foliage and they're heat-tolerant and drought-resistant, although begonias hate windy conditions. Begonia boliviensis 'Santa Cruz' has orange-red flowers that cascade over the edges of a container, supported by arrow-like neatly serrated foliage.
The similar 'San Francisco' is a lighter salmon pink/orange. You'll also find 'Cascade Red', 'Splendide Apricot', 'Illumination Salmon Pink' and 'Illumination Orange'. Or you could use the blush-white and pink 'Angelique', although it's the brighter colours that light up those shady spots.
Liatris
This midsummer butterfly and bee pleaser produces a flowering spike of purplish pink feathery flowers in the summer months. There's a popular form named 'Kobold' which is named after a German gnome and often used for shorter plants, but it still rises up to 18 inches or more. Plant in clusters for August and September flowers.
Nerines
The South African nerine has great timing: the flowers appear just as summer fades into autumn, so the agapanthus-like blooms are flattered by evenly balanced days. Nerine bowdenii will come up every year and it will flower in sunny positions, especially when the bulbs appear congested. They seem to enjoy being cheek by jowl against a sunny south-facing wall.
Wait for the ground to warm up, then plant the bulbs so that the top fifth is above the ground: think wallowing hippos. Water the bulbs well to begin with; once established, they are drought-resistant. Look out for the Guernsey lily, too – good ones include the soft-pink 'Vesta', the brighter pink 'Isabel' and the deep-magenta 'Mr John'. Amarines (crosses between amaryllis and nerines), have larger flowers that are especially good to cut, although they do have a strange almost coffee-like scent once indoors.
Dahlias
There are plenty of tubers on offer online and in garden centres and these should be started off between mid-March and mid-April. These are frost-tender babies bred from high-altitude South American species, so they should not be planted outside until early June. A late frost could be fatal. They also need their own space because they don't enjoy pushing up through other perennials. However, they are the ultimate cut-and-come-again flower and they will bloom for three months.
Choosing one dahlia is akin to picking a favourite child, but 'Penhill Watermelon' is a shaggy mixture of pink and soft-orange. The neatly rounded warm-pink ball dahlia, 'Jowey Winnie', and the dark-red 'Sam Hopkins' will also add pizazz. If I had to pick one, though, it would be the butterscotch-orange 'David Howard'.