Planning a vegetable garden? Options for urban plots
by Emma Cooper
© iStockphoto/Chris Price
The traditional advice for starting a new vegetable patch is to pick the sunniest possible spot, double dig the soil and improve it with barrow-loads of well-rotted horse manure and plant in orderly rows. In an urban garden, this might not be possible but that doesn’t mean you can’t start a flourishing edible garden this spring.
If you’re short on soil…
Soil can be a real issue in urban areas. It might all be buried under concrete or decking, or the bits you can use might be very low quality. Builders may have disposed of rubble by covering it with a thin layer of topsoil when they built your house; previously industrial areas may be blighted by pollution. The solution to all of these problems is to build the soil up above ground level, in raised beds or containers.
A raised bed is simply an area of soil that is higher than the paths surrounding it, but most have some kind of edging. You can make your own, using bricks or railway sleepers, or buy a ready-made kit that’s the right size. Raised beds can be built on top of concrete and paving slabs; on decking, consider putting down an impermeable layer first to protect the timber.
The depth of the soil governs what you can and can’t grow in a raised bed. A depth of 15cm (6 inches) is great for leafy vegetables and baby roots – look for ‘quick’, ‘early’, ‘dwarf’ and ‘container’ varieties. A depth of 20 to 30cm (8 to 12 inches) allows you to grow almost anything.
If you’re short on topsoil then you can buy in a few bags, or fill your raised beds with compost, well-rotted horse manure and any other organic matter you can lay your hands on. You can add loam, sand or grit to the mixture if you have them to hand, but they are not essential. ‘Lasagna gardening’ involves building beds with layers of different organic materials (mainly waste products such as straw, cardboard and newspaper). Lasagna beds are normally built in autumn; over the winter their contents begin to rot down and they are ready for planting in the spring. The advantage of lasagna gardening is that digging isn’t needed and the beds can be filled with cheap or easily available materials.
Alternatively, you can choose to garden in containers, which are available in sizes to fit any space. Again, the size of the container governs what you can grow – use smaller pots for leafy herbs and salads, and larger containers for crops such as perennial herbs and root veggies. A good potting compost is a suitable medium for almost all edibles (blueberries and other acid-loving plants need a special, ericaceous mix), but you’ll need to keep on top of watering and feeding throughout the growing season.
If you’re growing on a balcony or roof terrace, just remember to take the weight of the pots into consideration and check that the structure can bear the load. Use plastic pots, and potting compost rather than topsoil, to keep the weight down.
Wherever you choose to grow your plants, keeping your container crops well-watered will be the most time-consuming job. Consider investing in (or making your own) self-watering containers to keep crops happier for longer. Adding water-retaining granules, or seaweed meal, to the compost mixture also helps. Alternatively, there are plenty of automatic irrigation devices you can buy to make watering less of a chore.
If you’re short on space…
If you want to grow a variety of plants throughout the season, then have a look at Square Foot Gardening – a technique to make the most out of small spaces. The basic idea is that you divide your growing space into a grid of small squares, and grow something different in each one. You can mix flowers and vegetables, and the method takes care of crop rotation too – after each crop is harvested you replant the square with something different. It’s best to keep a steady supply of new seedlings on hand to plug gaps as they form. Square Foot Gardening is also a great system for time-poor gardeners, as you can easily weed or replant a square in a few minutes.
In a small plot, it also helps to make use of vertical spaces – there are plenty of climbing and scrambling edibles that can be grown up poles, fences or trellis. Some cling by themselves (peas and the exciting achocha spring to mind) while others need tying in, so keep some garden twine handy.
You can also grow a surprising amount in window boxes, provided you keep them well-watered and fed. They are ideal for herbs and cut-and-come-again salads, which are more likely to make it into the kitchen if you keep them close to hand. Dwarf beans, cherry tomatoes and even chilli peppers all look stunning and are productive despite the small space.
Grow bags are a great temporary fix if you’re very short on space or unable to make any permanent additions to a rented garden. Traditionally, they are laid flat on the ground and planted with two or three larger plants like tomatoes which then need constant watering and feeding. A lower-maintenance solution is to cut them in half and stand each half up to create two plastic ‘planters’ that are deeper and keep plants happier for longer. You can also use grow bags as a base and plant tomatoes into bottomless pots on top, which gives the plants extra root space.
If you’re short on sun…
Forest gardening is a modern approach that aims to mimic the way a forest grows by using layers of suitable edible or useful plants at different heights to make the best use of space and available light. Designing a full-sized forest garden is a big undertaking, but many of the plants used are adapted to growing in low-light conditions, and so are perfect for shady spots. They may not be familiar, but they’ll make for interesting meals. Siberian purslane is a lovely low-growing salad leaf, and chickweed (commonly thought of as a weed) not only has pretty white flowers in spring but is edible.
If this all sounds a bit adventurous, then there are plenty of more familiar edibles that grow happily in shade or partial shade. Lettuce hates too much sunshine, and all of the leafy salad and stir-fry vegetables will cope in a shady spot. Radishes and beetroot aren’t too fussy either, and you’ll manage herbs such as mint and parsley. If you have access to the soil then rhubarb is an option (it’s unhappy in anything but a very large container).
If you can’t live without a few strawberries, or cherry tomatoes, then plant them in a hanging basket – at head height it can be easier for them to catch some rays – but don’t forget that they’ll need feeding and watering.
If looks matter…
Some people find rows of vegetables attractive but if you’d like a less regimented look for your space, you can add vegetables into your flower beds to create a stylish, yet productive, garden. Just remember that veggies need better soil than most flowers, so add in some extra compost at planting time. Leave some space for stepping stones, so that you can avoid trampling the flowers while harvesting. Or consider a tough ground cover plant such as creeping thyme, which doesn’t mind being stepped on.
Lettuces are great ornamental edibles (or ‘edimentals’) as they come in a range of colours and some have frilly leaves. Plant more than you’ll need and you can leave some to flower and set seed – they grow into impressive pyramids when they’re past their edible best. Chard is a great leafy vegetable, and its glossy green leaves and coloured stems are eye-catching in the border. Alpine strawberries form attractive, leafy clumps and their tasty fruits create little spots of colour (red or white) over a long period. The ‘Crimson Flowered’ broad bean is worth seeking out for early spring colour, and both curly parsley and chives make lovely clumps for edging. Bronze fennel is a tall plant that can make a stunning addition to the back of the border.
If you’d like to fit your crops into an existing design theme, there are edible plants to suit every style. The bright colours and big leaves of nasturtiums, for example, are ideal for a tropical garden and the flowers are edible. Amongst the herbs, the delicate purples and blues of chive and borage flowers mean they’ll fit nicely into a cottage garden while the silvery foliage and scent of lavender and rosemary make them an ideal choice for a Mediterranean or Moroccan-style space. With just a few clever choices, you can have stunning flowers, fragrance and food from your garden all summer.