Dealing with Australian flatworms in the garden and planting heritage Irish apple trees

IT WAS OPW gardener Paul Whyte who first discovered them, while spring-cleaning a little-used corner of the walled kitchen garden. Raking off a thick layer of bark mulch and then peeling back the weed-

suppressant membrane that lay underneath, he found the half-dissolved carcasses of several dozen earthworms, while all around them – pale, hale and hearty – wriggled one of their deadliest predators, the Australian flatworm, Australoplana sanguinea var. alba.

“It was horrible,” says Paul, with a grimace of disgust. “One of the most sickening things I’ve seen in any garden. The flatworms had obviously been feeding on the worms for a while, poor things.” Did he know what they were straight away, I wondered?

“I knew for certain that they were flatworms, both by their shape and the fact that they were eating the earthworms, but I wasn’t sure what kind – there are at least two different types.”

Indeed there are, and, by a strange coincidence, Irish Timescolumnist Michael Viney wrote about them both in vivid and fascinating detail in last Saturday's paper. Yet while the better-known New Zealand flatworm, Arthurdendyus triangulatus, has long been the headline-grabber due to the fact that it's larger and more voracious, it's the lesser-known, smaller and paler Australian flatworm that is the more common of the two in mild Dublin gardens (ditto along much of the south coast). While both species of flatworm feed on earthworms, often with significant consequences for soil health, it seems the OPW gardeners aren't too worried just yet.

“After we’d gathered them up and killed them, I did some research online, just to identify which flatworm it was and to find out more about it,” explains OPW gardener Brian Quinn, handing me a glass jar with a couple of the flatworms carefully preserved in alcohol, so that I can have a look for myself.

“The thing is, both types of flatworms prefer to live on or near the surface of uncultivated ground and in damp and slightly acidic soil, which is the opposite of what they’d generally find in the walled garden. The soil is here is alkaline and free-draining, and we rotovate, dig or hoe most parts of it regularly.

“That little patch where Paul found them is the exception – the fact that it was covered with Mypex and then bark-mulch just happened to create the perfect habitat for the flatworms. The Mypex (the weed-supressant membrane) meant they were left undisturbed while the bark acidified the normally alkaline soil and kept it cooler and damper.

But how did they come into the garden? Neither Brian nor Paul, nor their fellow gardener, Meeda Downey, has a definite answer to that one. “I’d guess with a plant,” says Meeda.

“They can easily hide in the compost or even on the underside of the pot without being noticed (they also like to hide under black polythene, old carpet, flat stones or rocks). Their eggs can come in with pots too.”

Meanwhile, the OPW gardeners have had more urgent issues on their mind, such as getting a recent delivery of bare-

root apple trees into the ground before they burst into spring growth. The happy result of all their hard work is that the neatly-mown lawn just outside the main entrance to the walled garden has now been partly fenced-off with elegant, black metal railings and transformed into an apple orchard.

“We’re growing a lot of older, heritage varieties (as first chronicled and collected by the late Dr Keith Lamb) such as Ardcairn Russet, Kerry Pippin, Blood of the Boyne, Lady’s Finger of Offaly, and Irish Peach.

Most of them date back to at least the 19th century, or even earlier, and all of them were bought from McNamara’s Nursery in Midleton, Co Cork,” says Meeda, adding that they’ve been hugely impressed by the quality of the young trees that have been delivered.

This includes some very nicely-trained, young espalier apple trees (a mix of modern and historic varieties such as Elstar, Katy, Cox’s Orange Pippin, and Beauty of Bath), all of which will replace the espaliered pear trees that once flanked either side of the walled garden’s huge double herbaceous border. “We root-

pruned the pear trees early last month and then pruned the branches down by about a third of their original size,” explains Brian. “It made them easier to move and gave them the best chance of surviving after being transplanted – they’re now in a nice, sunny, south-facing spot in the new orchard, against the outside walls.”

Given the fact that they were largish, well-established trees, does he think that they’ll survive the shock of being moved?

“You can never really be sure. We’ll just have to keep them well-watered and then wait and see.”

The same careful waiting game will apply to the many herbs (sage, chives, fennel, marjoram, dill, tarragon, garlic chives and thyme) that were growing in small panels along the edges of the walled garden, but all of which have now been transplanted instead into raised drills in one of the large, central panels of the garden.

Likewise, all 36 thriving asparagus plants, their first plump spears just appearing above ground, have been carefully lifted by the OPW gardeners and transplanted into their new quarters next to the herbs.

“Just as they were finally ready to be harvested,” says Brian, regretfully. “Each of the crowns (the technical term for the resting asparagus plant) had huge, deep root systems, so it was a massive job to get them out of the ground without doing too much damage.

“But we have big plans for the garden this summer, including using the side beds to grow lots of traditional Victorian cut-flower varieties such as chrysanthemums and gladioli. Fingers crossed, the hard work that we’re doing now will all be worth it in a few months time.”

But as for the OPW gardeners’ much anticipated asparagus harvest, that particular waiting game now continues until next year.

WHAT TO: sow, plant and do now

Sow (in a heated propagator, to plant out later into a greenhouse, tunnel or outside):Aubergines (Bonica is best), alpine strawberries, French beans for cropping in pots inside (choose a disease resistant variety suitable for early sowing), asparagus, celery, celeriac, tomatoes, chillis, and peppers, physalis (Cape gooseberries). Also sow single tender flowers like French marigolds, tagetes etc. to attract beneficial insects which help with both pests pollination.

Sow (in modules under cover without heat, covering with fleece on frosty nights, for later planting in the tunnel or outside):beetroot, broad beans, mangetout and early peas, late spring and summer cabbages, red cabbage, early Brussels sprouts, cauliflowers, calabrese and summer sprouting broccolis, carrots(direct in soil for early tunnel crop), onions and leeks, spring onions, lettuces, kohl rabi, Ragged Jack and Cavolo Nero kale for baby leaves, radishes, Swiss chard, summer spinach, white turnips, salad mixes, and soft herbs like parsley, dill, fennel, greek oregano and coriander. Where youre not planting crops until May, its also worth sowing quick growing soft green manures like red clover, lupins, fenugreek, mustard and phacelia to help improve the soil and feed the worms - make sure varieties fit into your rotation pattern as far as possible.

(Sowing details courtesy of Nicky Kyle, nickykylegardening.com)

Plant outdoors:Seed potatoes (First earlies), onion sets, shallots

Do:Finish ordering seeds, hoe young weeds where soil is workable outdoors. Chit potatoes - and plant chitted early varieties in 2-litre pots in or direct into greenhouse bed for an early crop (planting to crop about 10 weeks) Dont plant in soil where youre going to grow tomatoes later - better to grow in pots, which an be moved outside later as space gets tight,

* McNamara’s Rose Nursery is owned by John McNamara and is situated in Dunsfort, Midleton, Co Cork 021-4613733

* Jimi Blake will be giving a course on Beginners Vegetable Growingat his gardens in Hunting Brook, Blessington, County Wicklow on March 27th (huntingbrook.com, 10.15am-4pm, €90).

The course will also include a visit to the Hunting Brook allotments for a practical, hands-on session. If you decide to rent one of the Hunting Brook allotments this year (€200 per year), you’ll also qualify for a 10% discount off the cost of the course, a selection of recommended vegetable seeds and a special one-hour allotment tutorial from Jimi.

* 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

* Next week:growing comfrey in the walled garden

* FIONNUALA FALLONis a garden designer and writer