Time for people in glasshouses to scrub up

URBAN FARMER:Wash the glass, get rid of sick plants: get to grips with grime, writes FIONNUALA FALLON

WITH THE OPW’s plans to reinstate the Jacob-Owen designed glasshouses in the Phoenix Park’s restored walled garden on ice, gardeners Meeda Downey and Brian Quinn have had to make do. So instead of Victorian vineries and pineapple houses, they’ve got temporary use of an old glasshouse in the nearby Klondyke nurseries.

This is where the OPW propagates many of its bedding plants for the city’s parks and streets, and is just a short drive from the walled kitchen garden. The good news is that the engineers have just finished installing a new heating system in all the glasshouses here, so Meeda and Brian will have no worries as regards keeping their young seedlings and plants frost-free.

The bad news is that the glasshouse they’ve been given hasn’t been in use for years. What’s more, when it was being used, it was as a shade-house, the consequence of which is that every pane of glass, including the roof, was coated with a thick, milky layer of shading paint to filter out the light.

“Actually, a thick layer of limewash which dates from the early 1960s, with a later layer of diluted white emulsion paint over it, if you want to be exact,” sighs Meeda, who along with Brian and fellow OPW gardener, Paul Whyte, has spent the last two weeks painstakingly removing it by hand with a scraper.

But that isn’t all the OPW gardeners have had to contend with. Along with the shading paint, they’ve had to slowly slough away the decades of grime and slime which accumulated in every corner and crevice of the glasshouse, inside and outside, along with the sludge and algae that coated the old glass roof. Outdoors, overhanging sycamore trees gave further problems, as the “honeydew” excreted by the aphids they harboured left its own sticky residue.

Using buckets of steaming hot water, washing-up liquid and long-armed scrubbing brushes, Meeda, Brian and Paul have spent a week painstakingly scrubbing every pane of glass they can reach.

A scaffold allowed them to reach just one side of the roof with difficulty, but no further. Power-hosing is out of the question due to concerns as to whether the old glass panes and the glazing bars would hold up to it – quite a few have already needed to be replaced.

“It’ll have to do,” says Brian resignedly, reckoning that there will still be sufficient light for the young plants to thrive.

But what’s worse is that although the old shade-house hadn’t been in proper use for years, until recently it still served as a store for any sick, forgotten or unwanted indoor plants (mostly from state buildings). “We’ve emptied it completely, including the soil in the central staging (the equivalent of an indoor raised bed) but the chances are that all those old plants were hosts to every kind of glasshouse pest and disease,” explains Meeda. “So before we plant anything, we’ll have to disinfect every square inch of the place.”

Meeda and Brian are absolutely right to worry about pests and diseases in the glasshouse, for young seedlings are particularly vulnerable. And now, before the sowing season begins in earnest, is a good time to thoroughly clean and disinfect your glasshouse or polytunnel if you’re lucky enough to have one. Otherwise, you run the risk of encouraging pests like red spider mites, scale, mealybugs, aphids and whitefly, viruses or overwintering fungal diseases such as tomato stem rot, all of which can seriously damage young plants, or worse . . .

“We’re scrubbing every inch of it with hot water and washing-up liquid after brushing it down, removing all the sick plants and excavating out the old soil. Then we’re going to spray it with a disinfectant solution, making sure that we get into every tiny crack and crevice. We’ll leave that to sit for at least a few hours and then hose the whole place down again,” explains Meeda.

The OPW gardeners are using diluted Jeyes Fluid as a disinfectant, but there are other brands available that will do the job as well, including Citrox (1 litre for €9.95, available from the Organic Centre, organiccentre.ie) or Armillatox (available from all good garden centres including Johnstown Garden Centre, 045-879073, 500ml for €14.99).

Even the overlap between the glass panes will get a going-over: the easiest thing to use here is a plastic plant label which fits neatly between the gap to scrape away any dirt or algae. The OPW gardeners will also be cleaning and disinfecting any pots, seed trays and tools they use, as well as the capillary matting.

The chore of cleaning and disinfecting will be a lengthy one (over two weeks) but the OPW gardeners are just grateful to finally have their very own heated glasshouse. “The new heating system is thermostatically controlled, so we can regulate the temperature properly, which is great. Our only worry is ventilation – it’s still a manual system, which means that on a sunny spring day, the temperature could suddenly shoot up if we’re not really careful,” says Brian worriedly.

The OPW gardeners know only too well that sudden extreme rises in temperatures would mean instant death for young seedlings and plants. “We’ll just have to be very careful,” says Meeda with a shrug.

But what about if one of those sunny spring days happens to be at the weekend, when both the gardeners are off-duty? Up until this year, the OPW has been able to have someone keeping an eye on the glasshouses, but now things are different. Times are tough and just like the much-anticipated Victorian glasshouses for the walled garden, the budget for overtime has been a victim of the cutbacks.

And so this spring the OPW gardeners aren’t quite sure if someone will always be available to keep a weekend eye on their seedlings. But they’re not going to let themselves worry about it unduly. “We’ll sort that out one way or another. The great thing is that we’ve finally got ourselves a glasshouse,” says Brian firmly. “Not quite the glasshouse we were originally expecting, but still a glasshouse, all to ourselves. Next week, if all goes to plan, we’ll be able to start sowing seed. I can’t wait.”

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 4.30pm

Next week Urban Farmer in Property will cover ordering seed for the new growing season

Fionnuala Fallon is a garden designer and writer

Correction: Peter Meleady is OPW gardener in charge of the fruit and vegetable walled garden at the National Botanic Gardens of Ireland, not in the Phoenix Park as stated last week

What to: Plant, sow and do this week
Sow (with heat): hybrid broccolis, mini cauliflower, celeriac, celery, leeks, onions, asparagus.
Sow under cover (mild gardens only): broad beans, beetroot, Brussels sprouts,summerand
autumn cabbage, carrots, leeks, lettuce, Japanese bunching, main crop and spring onions, radish,
orache, peas (mild areas only), cut-and-come again (CCA) crops. Sow outdoors (in mild areas/
very good growing conditions): broad beans, onions, kohlrabi, parsnip, peas, radish, spinach
Plant: garlic (well-drained soils only), onion sets, rhubarb (as sets), spring cabbage, shallots,
Jerusalem artichokes.

Do: dig and manure soils where they aren't frozen or waterlogged, order seed and seed potatoes
required and start chittingthem (remember to protect from frost damage), plan crop rotations for
this year, lift remaining parsnips, thin overwintering onions, check stored fruit&vegetables (apples,
potatoes, onions, carrots) for rot and frost damage, net brassicas to protect from pigeon damage.