It's not too late to sow annuals - and they're a perfect way to fill the gaps that weeding leaves behind
At this stage of the year, spring is well sprung. Organised gardeners have sown all their seeds, weeded all their beds and pruned all their winter-flowering shrubs, and they are now drawing up their lists of early-summer tasks.
Not in this garden, though. As usual, there will be some discrepancy between the garden that glows genially within my mind's eye and the one that reproaches me balefully from the other side of the window. Weeds and gaps. Pull the former and you get the latter.
But a gap, when you think about it, is nothing other than a planting opportunity: a place to be filled with something desirable - before the weeds have their sneaky way with it again. My very favourite gap-filler is night-scented stock (Matthiola longipetala), which emits a powerful fragrance of coconuts and cloves as soon as the sun goes down.
It is a spindly, unremarkable-looking annual, with mauve cross-shaped flowers (putting it in the Brassicaceae family, along with wallflowers, rocket and cabbage). The blooms curl up to almost nothing during the day, but when night falls they unfurl and pump out great surges of intoxicating scent.
One of the best ways to grow this Greek native is to sow it thinly in a tray of compost, or into growing modules (with a pair or trio of seeds per segment). When the seedlings are six to eight centimetres tall they can be tucked into empty spaces in the border.
While you've got the seed packet out, sow another few seeds in a pot, so that when the plants flower, in a couple of months' time, you can put the pot on your bedroom window sill - and have your night's sleep imbued with celestial perfume. Because of night-scented stock's unprepossessing daytime appearance, some gardeners mix its seeds with those of the related Virginian stock (Malcolmia maritima). The latter has roughly similar flowers (which don't shrivel in daylight) but no fragrance.
Both of these stocks may also be sown directly into a flower bed - but you'll need to keep a vigilant eye out for slugs and snails while the tempting seedlings are muscling their way through the soil.
Indeed, many annuals may still be sown now, and during the next month - either into the soil or in compost-filled trays or modules - and they'll reward you with a worthwhile show of flowers.
The end of May has been the traditional cut-off point for sowing annuals to flower in the same year. Yet our changing climate is bringing us earlier springs and longer, hotter summers, so it makes sense that sowing times can be adjusted to suit our warming globe. With this in mind, the seed company Mr Fothergill's has experimented with sowing a full month later. Thirty popular annual varieties were sown directly into the soil at the company's trial grounds in Suffolk at the end of June, and 15 of them gave fine shows of flower from summer until well into autumn. First to flower was the little echium 'Blue Bedder', and it was still going strong in mid-October.
Other annuals that performed well with the month-later-than-recommended regime were sunflower 'Giant Single', clary 'Bouquet', alyssum 'Carpet of Snow', calendula 'Art Shades' and Eschscholzia 'Single Mixed'. The last of these is none other than the beauteous, silky California poppy. Varieties of candytuft, Limnanthes (poached egg plant) and Gypsophila (baby's breath) also did well. Two unexpected sulkers, however, were Godetia 'Dwarf Mixed' and larkspur 'Hyacinth Flowered'.
The people at Mr Fothergill's also sowed 25 varieties of hybrid (F1) sunflowers in the last week of June, and the majority flowered successfully. The star was 'Firecracker', a dwarf kind (75cm) with many rust-and-yellow flower heads, and a branching habit that makes it suitable for a temporary low hedge. Sunflowers need to drink enormous amounts of water, especially if they are in dry soil and you want them to grow beefy and healthy. If your kitchen is near an outside door, then plant them in the soil there, sentry-style, and give them all your salad-rinsing and other spare water (many gardeners keep a bowl in their sink to catch useful water that might otherwise be wasted).
Sunflowers are exceptional in their thirstiness. Most other hardy annuals are fairly drought-tolerant, and don't need extra water once they are established. Bedding plants, on the other hand - which are highly bred to produce great quantities of larger-than-life flowers - may need constant watering and feeding in order to keep from languishing.
Usually hardy annuals are genetically closer to their native species, and are thus able to get along with less coddling by human beings. Among the more obliging are calendula, California poppy, candytuft, clarkia, cornflower, echium, gazania, nigella, night-scented and Virginian stocks, and zinnia.
Annual grasses such as hare's tails (Lagurus ovatus), larger quaking grass (Briza maxima) and squirrel-tail grass (Hordeum jubatum) are also well adapted to dry soil. Their flower heads, especially the gorgeously soft, blobby hare's tails, make long-lasting candidates for dried flower arrangements. Use annual grasses to edge borders, drives or paths - where their erupting gold and silver inflorescences will catch the light and dance in the breeze. Or you can float them through a border with other artless-looking annuals, such as cornflowers, poppies and nigella, for today's de rigueur meadowy effect.
The poshest annual to land in Irish gardens is the metallic-blue-leaved honeywort, Cerinthe major var purpurescens, a native of dry Mediterranean regions. It is a pretty thing with nodding heads of purple-blue tubular bells, protected by storm-cloud-coloured bracts. A group of plants together makes a low-lying foggy and iridescent shimmer, but you need to get down on your hands and knees to appreciate the curious attraction of the individual flower heads.
A far more ebullient annual, and one that I've always loved, is the much deprecated nasturtium. It loves poor, dry soil - and indeed, produces its best crop of jolly-jangly blooms (from pallid yellow to screaming orange to dignified maroon) in infertile ground. There are compact kinds that are perfect for edging vegetable beds or for planting in containers, and trailing varieties that clamber through hedges and over unsightly obstacles. Its common name comes from the Latin, nasus tortus, for twisted nose, because of the pungent taste of the leaves (the petals are slightly peppery, and are excellent for enlivening salads).
Its botanical appellation, however, is Tropaeolum, from the Greek word tropaion for trophy: the round leaves and the golden flowers reminded Linnaeus of shields and helmets. It's a fitting name for such a heroic plant, one that will fearlessly vanquish any gap, and look valiantly handsome in the process.