During pruning of the walled garden there was a surprise in pale turquoise

IT WAS only after he’d finished cutting back overgrown rhubarb stems in the OPW’s walled kitchen garden that gardener Brian Quinn stumbled across the blackbird’s nest. Cupped inside the songbird’s makeshift basket of twigs, grass and mud, he and fellow gardener Meeda Downey discovered a clutch of four freckled eggs, each of the palest turquoise and weighing (according to the British Trust for Ornithology) an average of 7.2 grammes – or slightly less than a €1 coin.

“I decided to pull away a lot of the older, tougher leaves, hoping to encourage the rhubarb plant to produce some juicy young shoots,” says Quinn. “It was only when the blackbird suddenly flew up and started chattering away that I realised I’d disturbed her.”

Not, he quickly adds, that the blackbird appeared to be too dismayed, for within a few minutes she was back in her nest and seemingly oblivious to any further disruption. And given the upcoming work schedule of the two OPW gardeners, that’s probably just as well.

“It’s a bit crazy at the moment,” says Downey. “The seedlings and young plants in the glasshouse are all screaming out for our attention but the recent dry weather meant we also had to spend a huge amount of time watering the walled garden, where everything is just bone dry. Young fruit trees, transplanted herbs, just-germinated seedlings of beetroot, carrots, parsnips, turnips, swedes and broad beans – all of them are in bad need of a drenching. You could spend all day watering, but then there’s so much else that needs to be done.

“For the next few days, we’re focusing on the glasshouse,” shrugs Quinn. “There’s too much to be lost if we don’t. We’ve got baby seedlings of celeriac, dwarf French beans, tomatoes, calabrese, leeks, basil, Florence fennel, cauliflower, courgette, cucumber, lettuce and sweetcorn, all of which have to be pricked out into individual pots or ‘six-packs’ if they’re to have any chance of doing well.”

Along with the thousands of vegetable seedlings in the OPW glasshouse, the gardeners also have the extra chore of pricking out hundreds of young seedlings of tender flowering bedding plants, such as dahlias, lobelia and helichrysums, all of which will fill up the newly-emptied side panels that run along the edges of the garden’s inner walls.

“We’ve given ourselves a lot more work by raising nearly all the bedding plants from seed, but it’s worth it because it means that the walled garden will look particularly beautiful this summer,” smiles Downey.

Watching Quinn and Downey as they rapidly prick out tray after tray of young seedlings, it’s clear that they have this time- consuming technique down to a fine art. Each “six-pack” or modular tray is quickly but carefully filled with a good quality potting compost (pressed firmly into each 9cm square cell) before being gently watered in preparation for planting.

“We also water the trays of young seedlings before transplanting, as it makes it much easier to then tease the roots out without damaging them,” explains Downey, as she begins to tenderly prise a clump of cauliflower seedlings out of its tray.

Holding each individual seedling by its leaves (never by its stem), Downey then uses her finger as a dibber to quickly make a small hole in each individual “cell” before lowering the baby seedling carefully into place and pressing the compost gently down around it. “Once you’ve pricked out the seedlings, it’s important to water them again,” adds Quinn. “It helps to settle the compost around the roots, which means the seedling is quicker to re-establish itself after the shock of transplanting.”

Quinn and Downey are also careful to avoid damaging young seedlings by over-vigorous watering. OPW gardeners use a watering lance (available from Fruithill Farm, fruithillfarm.com), which gives a gentle spray. A similar effect can also be achieved using an adjustable watering gun (look out for the Hozelock range, hozelock.com), or a handheld watering can with a “rose” attached to the end of its spout (Haws watering cans, haws.co.uk, available from Mr Middleton, are the best).

“When it comes to pricking out young seedlings, the trick is to be quick and careful,” says Downey. “You need to avoid damaging the seedlings in any way, whether that’s bruising the leaves, the stems or their fragile root systems but you also have to transplant the young seedlings very quickly as otherwise they will get stressed. Having said that, it’s really not as hard as it sounds.”

Which is probably just as well, given the fact that the OPW gardeners must prick out at least several thousand seedlings in the glasshouse over the next few weeks if they’re to stay on target as regards their carefully planned planting schedule.

Speaking of schedules, the blackbird has one of her own. Just the day after her nest was found, those four fragile turquoise-green eggs started to hatch out one by one. It’s now expected that the young fledgling blackbirds will spend up to 16 days being fed by both their parents, before they leave the nest.

By a strange coincidence, that’s around the same time that Quinn and Downey’s plants will also begin to leave the heat and shelter of the glasshouse for life in the walled garden. By then (mid-May), it will be time for both the baby plants and the baby blackbirds to start toughing it out for themselves in the great outdoors.

WHAT TO: sow, plant and do now

Sow in a heated propagator in pots or modules for tunnel cropping, or for planting outside under cloches at the end of May:French beans, runner beans, sweet corn, courgettes, gherkins, pumpkins, summer squashes, marrows and melons. You can also still sow cucumbers and tomatoes for late crops. Also herbs such as basil, coriander, dill, Greek oregano, parsley and fennel. Shade propagators and young seedlings from strong sun.

Outdoors, sow in modules, in a seedbed for transplanting, or in situ where they are to crop:asparagus, globe artichokes, beetroot, broad beans, carrots, all varieties of peas, savoy and other autumn/winter cabbages, all varieties of sprouting broccoli including calabrese and purple sprouting, cauliflowers, salad onions, Hamburg parsley, landcress, lettuces, perilla, orache, chicory, kohl rabi, kales, parsnips, radishes, rocket, salsify, Swiss chards, spinach, white turnips and swedes, summer purslane, lamb's lettuce, salad mixes and perennial hardy herbs including sorrel. Asparagus peas, cardoons and New Zealand spinach can be sown outside under cloches now.

Plant out:Kale, cabbage, cauliflower, celery, celeriac, Brussels sprouts, celeriac, leeks.

Do:earth up potatoes, keep seedlings and young plants well watered, begin to harden off well-established, module-raised plants, keep the glasshouse/polytunnel well-ventilated, put up protective netting (Bionet) against carrot fly, provide support for tall plants (beans, peas, tomatoes), hoe/hand pick weeds.

* The OPW’s Victorian walled kitchen garden is in the grounds of the Phoenix Park Visitor Centre. * The gardens are open daily from 10am to 4pm

* Next week, Urban Farmer will cover sowing peas, runner beans and French beans

* FIONNUALA FALLONis a garden designer and writer