In the Garden: Bulb plans now add colour to summer

People who have containers especially for summer flowers can find an overwhelming number of brilliant choices among the summer bulb offerings this year – including the purple-leaved, pink-flowered Oxalis triangularis that becomes a houseplant (and keeps on flowering) when you bring it indoors for winter.

Unlike most summer listings, this oxalis handles deep shade or semi-shade. It grows only 20 centimetres (eight inches) tall, but it covers its space thickly in a clump that slowly increases.

There’s also a green-leaved white-flowered version.

Deep shade isn’t usually suitable for plants that emit bright bursts of colour, but deep shade is the place where tuberous begonias are right at home, because strong sunshine can burn their leaves.

Begonia tubers are best sprouted inside, and planted outside in mid-May.

Flowers can be huge, with multiple petals in red, orange, yellow, white, and pink, and in shapes varying from picotees to fringes and ruffles.

Some gardeners keep begonias for years, taking them in every winter and putting them out after frost season.

The tubers keep enlarging and the number of flowers increasing.

Also happy in shaded corners are martagon lilies, which have several reflexed petals dangling along each stem.

Flowers of the old fashioned ones were mainly non-fragrant, and strictly purple-pink or white. They’re now being hybridized. One is the fragrant 150cm (60-inch) martagon lily ‘Arabian Night,’ with deep red and golden blooms.

Other groups of lilies need sun and rich soil.

The shorter, fragrance-free Asiatic lilies now have many double forms, as do the taller, richly scented Oriental lilies. Double-flowered tiger lilies are also obtainable.

It’s worth mentioning that, beautiful though double flowers can be, they’re often inaccessible to pollinators. Most pollinators can’t find their way through the maze of petals.

People who love vases of flowers inside their homes will find gladiolus gives lots of pleasure for little work – and little money, if you choose the inexpensive mixes.

Unfortunately, gladioli are high maintenance in ornamental beds, needing early staking, which has to be removed once the flower stem is cut.

But out of the way in the vegetable garden or in random, sunny corners, a few corms planted every week, from April to mid-July, give a whole summer of beautiful gladiolus flowers.

Stray cormlets, dropped off the old corms, easily germinate and grow through a mild winter – but usually die later.

In slug-ridden gardens, dahlias are often more fun and less work if they’re grown in containers.

Containers don’t suit large-growing dahlias, but there are more patio dahlias available now, ranging from about 35-50cm (14-20 inches).

Containers can be ringed with various copper protectors (copper slug tape, or the woven wire ‘Slug Shield’) to avert slugs. That’s why container dahlias are a good choice for busy people who don’t have time – or rugged enough stomachs – to try any of the multitude of slug-murdering opportunities.

Eucomis species and hybrids aren’t usually standouts, though they flower for months once they start, and the seedheads are decorative. But the cultivar ‘Leia’ is quite spectacular, with a fat spike of bright pink flowers and wavy leaf edges.

These ‘Pineapple Lilies’ are very close to being hardy, but it’s still safer to bring them inside for winter.

For coastal gardeners, a south or west house wall and mulching is usually enough protection.