The OPW's gardeners prefer to sow most of their vegetable seeds indoors – so they can be sure seedlings won't be eaten by slugs, birds or hit by late frosts, writes FIONNUALA FALLON
WHATEVER ABOUT the walled kitchen garden, spring has finally sprung in the OPW’s heated glasshouses in the Phoenix Park, where gardeners Meeda Downey and Brian Quinn have been busily sowing seed for the last few weeks.
Already the long, waist-high benches are filling up with neatly-labelled trays (some already full of fragile seedlings), which jostle for position alongside the boxes of still-chitting seed potatoes. So far, the gardeners have already sown celeriac, celery, cabbage, tomatoes, garlic chives, Welsh onion, rocket, basil, parsley, cumin and coriander, and that’s just a fraction of what’s to come. “We’ve got a huge box that’s crammed to the top with seed packets, so the next few weeks are going to be a bit mad,” laughs Brian.
Unlike other urban farmers, Meeda and Brian prefer to sow the majority of their vegetable seed indoors before transplanting it out later in the spring.
“We generally sow almost all of our seed indoors in the heated glasshouse, with a few exceptions such as the carrots and parsnips which are sown in situ. That way, we can be more sure of successful germination and don’t have to worry about vulnerable young seedlings being eaten by slugs, damaged by birds or hit by late frosts,” says Brian.
“Instead, we prick off the seedlings into individual pots and then let them grow on in the glasshouses. Then, when the young plants are strong enough, we ‘harden them off’ (gradually accustom them to lower temperatures) before planting them into their final growing positions in the walled garden. But that won’t be for quite a while yet.”
Just as they did with the tobacco last summer, Meeda and Brian are sowing seeds of some “curiosity crops” for the walled garden this year, including wormwood (whose aromatic oil is a constituent of absinthe) and the toothache plant (Acmella oleracea or Spilanthes acmella), so named because its flower-buds contain a mouth-numbing, antiseptic alkaloid called spilanthol. Alternatively known as Szechuan buttons, or “buzz buttons”, its taste has been likened by some “to licking a nine-volt battery”, and experimental chefs have been enthusing about the distinctive citrussy flavour. It will be interesting to see how customers at the next-door Phoenix Café (to where much of the fresh produce grown in the walled garden goes) will react to it.
As celeriac grew particularly well for them last summer, Brian and Meeda have decided this year to grow two varieties (Prague Giant and Prinz) of the bulb-like vegetable. Notorious for its erratic, slow germination and its particularly long growing season, it was one of the first vegetables to be sown in the glasshouse.
“You need to sow the seed early if you’re to have any hope of a decent crop,” says Brian. The OPW gardeners will also take special care when it comes to hardening off the young celeriac plants, as any sudden drop in temperature will cause “bolting” (where the plant decides to flower rather than develop its distinctively knobbly root).
This is also true of coriander, the half-hardy annual herb whose pungent leaves are so delicious in curries and stews. “It runs to seed very easily, although Leisure, the variety of coriander that we’re sowing this year, is supposed to be unusually slow to bolt. Either way, we’ll keep the young plants in the glasshouse until late spring, when the weather should be warm enough for them to go outdoors,” Brian explains.
The gardeners have also sown two types of celery, including the vigorous Granada variety, a favourite with organic growers because of its high disease-tolerance, and Victoria, a paler, quick-growing celery considered to be one of the best in terms of flavour. And of the hundreds of tomato varieties, they’ve chosen three – Octavio, Sweet Olive (baby plum, early ripening) and Tumbler (ideal for baskets or window boxes).
“We’ve sown the seed but we still haven’t decided whether we’ll actually grow tomatoes in the walled garden this year,” shrugs Brian. “Meeda’s worry is that we’ll have too much on our hands to be able to look after them properly, particularly now that, with the cutbacks, we won’t have any students to help us.”
The OPW gardeners are experienced old hands when it comes to the business of sowing seed, and are full of useful tips and advice. “We use a good quality seed compost which we tamp down into the tray, but not too firmly, leaving it about an inch short of the top. Then we water it well before sowing. Try to sow the seed evenly and not too thickly, and then cover it with a light layer of damp (not wet) compost.
“We use a soil riddle or sieve for this, to make sure there are no lumps that could stop seedlings from emerging. But don’t cover the seed too deeply, which is a common mistake. After that, we label and cover the tray with cling-film (the cheapest one the supermarket has), which keeps the heat and moisture in until germination takes place. Remember, each morning, to tap off any condensation that forms.
“Once the seedlings start to appear, take it off. That’s why we leave that inch of a gap – so that the cling-film doesn’t touch the young seedlings as they emerge.”
Brian also warns urban farmers to protect seeds/seedlings against any sudden fluctuations in temperature caused by frosty nights, cold draughts or direct sun – the aim is to keep the temperature at a constant. Most vegetables and herbs require temperatures of about 13-16ºC to germinate (use a heated propagator), but once they’ve done so, a temperature of around 7-10ºC in a bright (but not sunny) position is what most young seedlings need to thrive.
Other useful advice includes staggering sowing at two-to-three week intervals (successional sowing), to avoid gluts and prolong the cropping period. But remember to order enough seed for this purpose, as the gardeners discovered to their cost last year.
“We ran out of seed of things like beetroot, lettuce, radishes and carrots by mid-summer and couldn’t get anymore,” says Brian, who has one further, slight shamefaced word of advice on the subject.
“Just don’t do what I did last week, which was to spill a full packet of parsley seed all over the pile of seed compost. By the time we’d discovered what had happened, it was way, way too late. There are going to be young parsley seedlings popping up in some very strange places over the next few weeks.”
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 will cover planting rhubarb in the walled garden
Fionnuala Fallon is a garden designer and writer
WHAT TO: sow, plant and do now
Sow under cover with heat (minimum 20ºC): tomatoes, aubergines, peppers, celeriac
Sow under cover (13-16ºC): beetroot; Brussels sprouts; hybrid broccolis; dwarf beans; lettuce; cut-and-come-again crops; leeks; kales; mini, summer and autumn cauliflowers; celery; endive; orache
Sow outdoors (favourable growing conditions, mild areas): broad beans; broccoli raab; summer, autumn and winter cabbage; radish; spinach; curly endive; mini, summer and autumn cauliflowers; calabrese; kales; lettuce; parsnip; peas; turnips; cut-and-come-again crops
Plant (in mild areas, favourable growing conditions): early and maincrop potatoes; onion, garlic and shallot sets; Jerusalem and Chinese artichokes; lettuce; rhubarb (as sets)
Do: weed, dig and manure beds; prepare seedbeds; disinfect glasshouses/polytunnels/seed trays, etc; order vegetable/herb seeds and seed potatoes; chit seed potatoes (protect from frost damage); plan crop rotations
