Potting mix and plant food

One of the beauties of balcony gardening is that you definitely won’t need to buy a lawn mower. There are, however, a few essential resources that are worth getting your hands on before you start turning your balcony into an edible Eden.

Large containers need less frequent watering than smaller pots.

Which compost?

 Obviously, when you first plant anything, you need to buy potting mix. The one you buy depends on what you are growing: annual vegetables, fruit, and flowers are happy with one that is general, soilless, organic, and peat-free; acid-loving crops such as blueberries need lime-free compost; while fruit trees and bushes, which will live for many years, will benefit from a soil-based potting mix, which releases its nutrients slowly. Unless it is stated otherwise in this book, assume that any crop is happy to be planted in general soilless potting mix.

Won’t I have to replace the potting mix constantly?

Luckily, no, or you would have a back-breaking time ahead of you, constantly carrying new bags of potting mix upstairs—also it would not be a very sustainable way of gardening, and pretty expensive.

Hungry crops, such as tomatoes, potatoes, bell peppers, eggplants, zucchini, and squashes, do need fresh, fertile compost to grow really well, but others, such as carrots, peas, beans, greens, and herbs, don’t require so many nutrients. If you grow hungry crops in fresh potting mix you can then reuse it for less hungry crops. To reuse potting mix, sift it through your fingers, removing as many roots as you can since these can stop water draining through and make it difficult for new roots to spread out. You can add the old roots to your wormery or compost bin. Top this old compost with a third fresh general potting mix and, if you have a wormery, a few scoops of fresh worm compost. A handful of slow-release plant food will revitalize old potting mix too.

Worms on the roof Measuring only about 2 square feet, wormeries are ideal for balconies and are fantastically helpful—not only can the worms digest kitchen waste, old roots, and prunings from a past crop, but by adding a few scoops of highly nutritious worm compost to your old compost you can inject new life into it, thus making it ready for a new crop. Worms also produce a highly nutritious liquid feed for your plants. (See this page for more information.) Feeding and drainage Apart from the plants, seeds, compost, and containers, of course, there are a few other items that are worth buying to set up your balcony. Most crop plants need feeding, and a good reliable feed is organic, sustainably sourced liquid seaweed feed that you dilute according to the instructions on the packet. (Any tomato feed can be used in the same way.) A bottle should be enough to see you through the whole growing season and will ensure your plants get all the nutrients they need. Herbs and fruit trees will benefit from a few additional handfuls of horticultural sand or grit being mixed into the potting mix when they are first planted (which will improve drainage), so it’s a good idea to buy a bag or two of these as well. Add a garden trowel, a pair of pruning shears, some garden twine, and bamboo canes and you’ll be ready to start work.

The Easy Edible Balcony

Many of us dream of growing our own greens, herbs, and tomatoes to eat at home, but worry that we can’t spare the time and energy to do it properly. Visions of returning to brown, dry plants after a weekend away instantly come to mind, or fruit and vegetables that never ripen. But if you choose the right crops and follow a few simple growing tips your edible balcony can flourish without making many demands on you at all, even if you are a total beginner. It doesn’t take long to set it all up, either; over a weekend you could transform your balcony to an emerging wonderland of shoots and fruits.

Plants not seeds

If you don’t have the time or the space to raise plants from seed, buy seedlings from garden stores or online suppliers and set up your entire edible balcony over a weekend. Plants ordered from catalogs or Web sites will arrive via the post and can simply be transferred to the potting mix as soon as they arrive. You may not be able to choose from quite the number of varieties available as from seed, but the range is expanding all the time.

Crocks away

When planting in containers it’s traditional to add a layer of “crocks”—pieces of broken terracotta pots—to the bottom to aid drainage. These are not always easy to source, so you can use chunks of polysytrene packaging instead—the trays that seedlings come in from garden stores are ideal. This material has the added benefit of being really light, too, which is perfect for gardening on balconies.

Easy peasy: tips for hassle-free balcony gardening

Big is best

When choosing containers, make life simple for yourself by not filling your balcony space with numerous tiny pots, as these will dry out the minute you turn your back. Instead, use large, lightweight containers, such as those made of plastic and galvanized metal. Troughs are ideal since they seem to hold their moisture better than round pots and fit snugly around the edge of a balcony, nicely positioned for, say, beans and peas planted in them to grow their way up the railings. Any “patio” planters marketed as being good for growing fruit and vegetables are great for the “no-time” gardener. Light and easy to set up, they can come in bright colors or with attractive woven willow panels to make them look attractive. Plastic bucket trugs are also perfect; they are readily available, cheap, light, and brightly colored, so they will cheer up the dullest of spaces. Do keep in mind that although the container may be light, wet potting mix is not, so check with a structural engineer if you’re at all worried about your balcony supporting the weight.

Self-watering pots

There’s no getting away from it: containers dry out more quickly than garden soil does, and if you’re several stories up, the wind won’t help this desiccation, but there are ways to take the hassle out of watering. Consider planters with a built-in reservoir —easily available in the stores or simple to make—which can keep even thirsty plants such as zucchini and tomatoes content for several days between waterings.


We’ve all been there—you’re on your way back home after a long weekend away and you suddenly remember with a sick feeling of dread that your tomato plants haven’t been watered for three days. You return to find them wilted and very upset indeed. However, if you make one of these ingenious self-watering planters, long guilt-free weekends will be yours once again.

These containers have a built-in reservoir of water so the plants can take up moisture through their roots for several days before the reservoir needs to be refilled. You may not want to make lots of them, but if you have particularly thirsty plants, such as zucchini, tomatoes, or eggplants, they’re ideal. There are plenty of more complicated versions of this system, but the one described here is beautifully simple and easy to make with things you’ll probably have lying around the house.


You will need

  • Scissors 1 medium (around 5 in.-diameter) plastic plant pot
  • 1 large planter—a plastic storage box with holes drilled in the bottom is perfect
  • 1 large plastic bottle—a
  • 1-gallon one is ideal, with lid on
  • 1 length of pipe about the same height as your planter—plastic garden hose is fine; a rigid plastic water pipe is ideal
  • Soilless potting mix Funnel (optional)

How to do it

With your scissors, cut about a dozen holes in the sides of the plastic plant pot, then cut a hole in the side of the bottle so that the plant pot fits snugly into it. Push the plant pot into the hole as far as you can, making sure the bottom is not touching the side of the bottle. Lay the bottle on its side on the base of the planter with the pot facing up. This will act as your reservoir.

Next to the pot, cut a smaller hole in the bottle just big enough for the pipe to fit into and push it in. Fill the plant pot with potting mix, pressing it down firmly. Then fill the reservoir bottle by pouring water into the pipe (a funnel makes this much easier). Finally, fill the planter with potting mix as normal and plant your plants. You can keep filling the reservoir via the pipe every week or so.

Timers of the essence

If you have easy access to a water supply, a simple automatic watering system is a great help. The most basic version is probably a timer fitted to your outside tap which is connected to a plastic tube with drippers coming off it at intervals of your choosing. This means you can direct these little drippers into your pots. Simply set the timer to come on for five or ten minutes twice a day and your plants won’t need you nearly as much.

Mulch it

Another way to cut down on watering is to mulch the surface of the potting mix when you first prepare a container. This simply means spreading on a thin layer of wellrotted manure, garden potting mix, shingle, pebbles, or bark chippings so water cannot evaporate as quickly from the potting mix. You can use shredded paper, sheets of newspaper, plastic, or grass clippings too, but shingle is ideal on a balcony or roof since it looks attractive and won’t blow away. To get the very best start, water the potting mix well before you first sprinkle the shingle on.

Crystal clear

Another handy watering tip, when planting in smaller containers such as hanging baskets, is to mix in a handful of water-retaining gel or crystals. These swell up, absorbing the water, and then slowly release it into the potting mix.

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