Jane Powers plants some edibles for an apartment terrace
"Do you think I could grow some herbs in pots on the deck outside my new apartment?" asks my physiotherapist while doing something unpleasant to my lower leg. Perhaps she's only trying to distract me from the discomfort, but that's fine with me. Either way, it gives me a chance to talk for half an hour about my favourite subject: other people's gardens.
Róisín's new ground-floor apartment has a small treasure of an outside space: more than two metres by six (six feet by 18 feet) and near enough to the sea that it has the benefit of the milder climate but far enough that it avoids the scourge of the salt. What's more, it's south-facing. So, yes, of course she could grow herbs. They are mainly Mediterranean plants, and they would be as happy as Larry in these congenial conditions.
But why stop at herbs? With more than 12sq m (130sq ft) of sunlit space, she could grow organic produce for eight or nine months of the year. Tomatoes, chillies, beans, peas, spring onions, leeks, aubergines, beetroot, spinach, chard and a host of different salad leaves could be hers for the picking. She could even have spuds - although they'd probably be best left until next year (when they can be started in March and harvested by midsummer).
Yet I mustn't fill up her entire outdoor space with suggestions, as she'd probably like to be able to sit there and relax from time to time. So,instead of going for self-sufficiency, she could concentrate on raising a few extras to delight her dinner plate: a couple of tomato plants, with some chillies in smaller pots at their feet; a wigwam of runner beans; some spring onions and radishes; and a mixed planting of interesting leaves, to be snipped young and used to enliven salads. These wouldn't take up too much room; nor would a couple of pots of edible flowers, such as violas, cornflowers and nasturtiums. And the herbs, we mustn't forget the herbs. Don't worry, we'll squeeze them in somewhere.
ASPECT
Hot-climate produce, such as tomatoes, chillies and aubergines, love a south-facing position, but there are plenty of other edibles that grow happily in a less baking situation. Most vegetables manage with a few hours of direct sunlight, while some leafy crops, such as lettuce, spinach, mizuna and sorrel, tolerate light shade - as do parsley and mint. Shelter is as important as sunlight: if a spot is windswept, forget about growing anything culinary other than thyme, rosemary and other hard-leaved herbs. Or filter the breeze with some kind of a windbreak.
CONTAINERS
Bigger containers are definitely better for most crops. Those that hold a greater volume of compost stay moist for longer, are less inclined to overheat and offer a more constant growing environment. And, for lanky plants, such as vine tomatoes or runner beans, they are less likely to keel over in the wind.
Low-growing foodstuffs, such as lettuce and other salady things, are okay in depths of 15-20cm (six-eight inches), as are most herbs. But containers 30 to 45cm (12-18 inches) deep are better for most vegetables. The choice is pretty limitless; that is, you can grow vegetables in just about anything with sufficient volume and with drainage holes in the bottom. Pots and troughs may be made of terracotta, plastic, galvanised steel or modern composites. Wooden half-barrels and fancy Versailles boxes are further choices.
The recycled option includes old Belfast sinks, galvanised water tanks, buckets, basins, baskets, wooden wine crates, bread bins, caterers' tins, coal scuttles, defunct kettles, pots and pans, and whatever you're having yourself.
Just be sure to drill, cut or puncture plenty of holes in the bottom if there are none already. No plant wants to sit with it roots in stagnant, swampy compost.
COMPOST
Most of the proprietary multipurpose potting composts are based on peat, a non-renewable resource. So peat is out for diehard environmentalists.
But it is difficult to find a readily available substitute that is as easy to use. Some non-peat composts are overly chunky or behave differently when you water them. With coir (a by-product of the coconut-processing industry), for instance, the surface dries off but the rest of the compost remains damp, so a person may be tempted to over-water.
John Innes composts (John Innes is a formula, not a brand name) contain some peat but are mainly soil-based. For plants, such as perennial herbs, that are going to be containerised for a long period, use John Innes No 3, with some extra grit or other compost to lighten its composition.
For other food crops, use peat-based composts if you will, but do experiment with more sustainable alternatives. Even if you mix peat-based and non-peat-based composts together, you are lightening the load on the environment. Heavy composts need a 5cm (two-inch) layer of drainage in the bottom of the pot. Use crocks (broken pot shards) or bits of polystyrene.
FOOD AND WATER
Containerised vegetables like moist (but not soaking) compost, and they may need watering most days. Water thoroughly, until you see little dribbles coming from the drainage holes. Crops with a large surface area - beans and spinach, for instance - need a lot of water.
Nutrients leach out of the compost quickly because of the constant watering, so a liquid feed may be necessary every week or two. There are lots of off-the-shelf preparations, including organic ones.
Gardeners with access to well-rotted farmyard manure can mix some into the compost in the lower half of the container. You can also use pelleted chicken manure (from garden centres) in the same way.
This should stave off the need for frequent liquid nutrition, although if the leaves turn pale and wan you'll need to start feeding. Salad leaves, spring onions, radishes and herbs are less hungry than other crops.
PESTS
Aphids (greenfly) and slugs and snails are the main enemies. Aphids congregate on the undersides of leaves and around the buds. Gently brush them off with your fingers or, if you're squeamish, with a tissue.
Look out for slugs and snails under containers or in other damp and shady hiding places. Hunt them at night and dispose of them in whatever manner your conscience allows.
WHAT TO GROW
Almost anything can be grown in a container, provided there is enough room. It's too late to start peppers, aubergines and tomatoes from seed, but look out for baby plants at garden centres and plant sales. Bush tomatoes, including tumbling kinds, are ideal. Those with smaller fruits do better outdoors. Most seed companies, including Thompson & Morgan and Mr Fothergill's, offer compact vegetable varieties for container growing, including the pretty, dwarf runner bean 'Hestia'.
Diary date
Thursday, May 4th, 8pm: Dublin 5 Horticultural Society plant sale and gardeners' question time, at Artane and Beaumont Recreation Centre, Kilmore Road, Artane. Admission €2