URBAN FARMER:AS THIS year's difficult growing season has now proved beyond doubt, Mother Nature occasionally takes a perverse delight in thwarting the expectations of even the most experienced gardeners.

In the case of the OPW’s walled kitchen garden, this means that normally-successful crops such as sweet corn, pumpkins, French beans and courgettes are at least a month behind, as the plants struggle to make up the growth lost to the unseasonably cool summer temperatures. Meanwhile, its onion crop – of which very little was expected due to the baleful presence of onion white rot in the garden – has been a bumper one.

What makes this success all the stranger is the fact that this has been an especially difficult year to grow onions, with many gardeners discovering that their crops are bolting or flowering, rather than swelling as they ought to. This year is also the very first time that OPW gardeners Meeda Downey and Brian Quinn have grown the walled garden’s onions from seed rather than sets – a process that many gardeners dismiss as being too time-consuming and difficult.

“We’re amazed by how well they’ve done,” says Brian. “Along with the ‘Banana’ shallot, we sowed seed of white and red onions (‘Ailsa Craig’ and ‘Red Baron)’ into plug trays in the heated glasshouse back in February and then planted them out in April.

“They’ve all produced really large fat bulbs, particularly the white variety. No sign at all of them bolting, although we did notice just the tiniest bit of onion rot just beginning to appear in one or two of them, so we’re going to have to harvest them straight away.

“We’ll definitely be growing them from seed from now on, particularly as it allows us a far greater choice of varieties. It’s also one of the best ways to help prevent diseases like white rot getting into a garden. Now I just wish that we’d used seed from the very start,”, concludes Brian, who harbours the suspicion that a contaminated onion set may have been the way that the disease (which persists in the soil for many years) first entered the walled garden some years ago.

Indeed, a quick browse of the seed catalogues confirms the fact that the choice of varieties is far greater, and includes some unusual types of main-crop onions such as the torpedo-shaped, dual-purpose, heritage 2Rouge Long De Florence2, the pickling onion “Paris Silver-Skinned” (both from Thompson Morgan, (thompson-morgan.com) and “Lafort” (sourced originally from the Wellbourne gene bank and regenerated by Irish Seed Savers, (seedsavers.ie).

And while it’s obviously far too late to sow maincrop onion varieties this year, for early autumn-sowing, there’s the hardy “Hi Keeper” (T&M), while both Suttons Seeds (suttons.co.uk) and Kings Seeds (kingsseeds.com) stock “Senshyu Semi-Globe Yellow”, a heavy-yielding variety specially bred for direct sowing from mid to late August to mature the following year in June-July.

Recommended by the independent, UK-based National Institute of Agricultural Botany, this Japanese bulb onion variety can alternatively be sown under glass in January/February and then planted out in March/April for a later summer crop.

Back in the OPW’s walled kitchen garden, along with their bumper crop of onions, Brian, Meeda and fellow gardener Paul Whyte have also started lifting what’s shaping up to be a fantastic harvest of new potatoes.

“Because of the dry spring and the cold June, we left the earlies in the ground for about a month longer than normal,” explains Brian. “We wanted to give them a proper chance to swell and fatten up.”

The result of the gardeners’ patience is a truly bountiful crop of a variety called Colleen with 12-15 large potatoes per haul (the other early variety growing in the garden, Orla, is still waiting to be harvested). “I think we got a particularly good crop this year because we left more space than usual between the rows,” suggests Brian.

Along with the earlies, the OPW gardeners are also growing a selection of maincrop varieties including the blight-resistant variety “Sarpo Mira”, which both Brian and Paul are curious to taste (they each have strong doubts as regards it being flavoursome).

Also growing in the walled garden is the variety “Arran Victory”, a white-fleshed, floury, late maincrop potato bred back in 1918 by the master potato breeder Donal McKelvie and named in honour of the ending of the Great War.

“It’s one of those potato varieties that you hear a lot about, particularly from older gardeners, which is why we wanted to grow it,” explains Brian.

Of course, a large part of “Arran Victory’s” legendary popularity stems from the fact that as a nation, the Irish have traditionally always preferred floury potatoes.

And if you do happen to like your potatoes floury (as Brian, of course, does), than there are few varieties flourier than this one. Just ask the potato expert and author of The Potato Book, Alan Romans, who when asked in a recent foodie poll what his favourite recipe for mashed potato was, replied with just two words: “Arran Victory”.

- The OPW’s Victorian walled kitchen garden is in the grounds of the Phoenix Park Visitor Centre, beside the Phoenix Park Café and Ashtown Castle. The gardens are open daily from 10am to 4pm

FIONNUALA FALLONis a garden designer and writer

WHAT TO: sow, plant and do now

Sow outdoors in pots or modules, for later planting in the tunnel or greenhouse when space permits for late autumn/early winter protected crops: Kales such as Cavalo Nero, dwarf green curled and Ragged Jack, Florence fennel, kohl rabi, Swiss chards, early peas, dwarf broad beans, sugar loaf chicory, basil, coriander, dill, plain leaved and curly parsley and sorrel. Covering while outdoors with a fine mesh covered frame or cloche will give young seedlings protection from pests (like cabbage root fly and cabbage white butterflies), and also scorching sun, strong winds and heavy rain.

Outdoors, sow in modules, in a seedbed for transplanting, or in situ where they are to crop:beetroot, brocoletto Cima di Rapa, carrots, cabbages (Greyhound and leafy non-hearting spring types**), overwintering spring-heading cauliflowers, Florence fennel, Witloof chicory (for winter forcing), sugar loaf chicory, radicchios, endives, salad onions, claytonia, landcress, lettuces, kohl rabi, Hungry Gap kale (for spring cropping), radishes, rocket, Swiss chards and leaf beets, summer spinach, summer white or yellow turnips, Chinese cabbage, Choy Sum, Pak choi, mizuna, mustard Red Frills and other oriental leaves, Chinese kale (Kailaan), lambs lettuce, salad mixes, herbs such as parsley, chervil, coriander, dill, fennel, buckler-leaved and French sorrel. Also sow some single, quick growing, annual flowers such as limnanthes (poached egg flower), calendula, Californian poppies, nasturtiums, phacelia, etc. to attract beneficial insects like hover flies to help with pest control, and bees to help with crop pollination. Sow fast growing green manures like buckwheat, red clover, mustard (a brassica, so watch rotations) and Phacelia, to improve the soil, lock-up carbon and feed worms (after digging in), on any empty patches of ground cleared of early crops that wont be used for six weeks or so, or which needs improving.

N.B. Sow in the evenings if possible as germination is sometimes affected or even prevented by too high a temperature - this applies particularly to lettuce.

Do:Plant out any well-established, module-raised plants, earth up potatoes, continue to harvest earlies, spray maincrop against blight, keep seedlings and young plants well watered , keep glasshouse/polytunnel well-ventilated, feed tomatoes, put up protective netting (Bionet) against carrot fly, cabbage root fly, cabbage white butterfly (inspect for eggs caterpillars also), provide support for tall plants (beans, peas, tomatoes), hoe/handpick weeds, protect vulnerable crops against slug/snail damage, continue harvesting/ storing produce.

- All sowing details courtesy of Nicky Kyle at nickykylegardening.com