Growers corner: Growing in Small Spaces

You might think you have no space to garden, but the good news is you can grow food almost everywhere. And in fact, smaller gardens will get more attention per square metres and often end up looking glorious as a result.

Whether it’s a balcony, a courtyard, a windowsill, a terrace or even a rooftop there are things you can grow. And to grow successfully in small spaces you need to look at the trinity: sun and water, containers, and plant choices.

Sun & Water

If you are growing on a rooftop or a courtyard check that you have access to water (and a watering can to get your water to the plants). If it’s going to be a nightmare to get water in your garden, check if you can have a water butt, or pick plants that favour drier conditions - like succulents. They will still need watering, but they will be able to do better with longer periods of no watering.

On a nice sunny day check your growing area every hour or so, and mark down for how long the sun hits your growing area directly. This will tell you where your garden stands sunwise between full sun (6+ hours of direct sunlight) to deep shade (less than 2 hours of direct sunlight per day).

You can grow food in most conditions, but if you plant a sun-loving variety in a dark corner - like a tomato on a north facing wall - it won’t be very healthy and it might not even fruit. If your growing area is really dark and shady (like shaded by buildings or overhanging trees), there are tricks that might help make it brighter like painting the walls white or using mirrors to reflect some sunlight. For a list of plants to grow for each level of sun, find a vegetable sunlight chart.

Containers

Once your sun and water is sorted you need to look at where you will grow. Small spaces often require containers as there is either no soil to grow in, or if you are in a city, the soil is likely to be a low quality or potentially polluted. Growing in pots and containers has its advantages: you can fully control your plant’s environment, from the soil it grows in, to the watering and feeding you provide, to the level of sun it will get (most pots can be moved).

The good news is that you don’t need to spend hundreds of pounds on fancy pots and containers, because almost anything can become a plant pot as long as:

• It is not see-through: most fruits and vegetables do not like light on their roots (so water bottles aren’t ideal for example)
• It has drainage holes: either on the bottom, or slightly up on the side of the container if you want to create a reservoir at the bottom of your pot.
• It is the right size: the smaller the container, the more watering it will need. To make things easier, look into getting plates or trays that fit under the pots and will catch and retain water. Equally you don’t want to grow a tomato plant in a mug size pot, so you also need to match the pot size to the final size of your plant.
• You check the material: is it thick enough to hold soil and not break? Wood and metal containers will benefit from being lined with damp-proof membrane to increase their life cycle and provide extra insulation for the plants.

What to fill your container with is the next challenge, as not all soil is equal, and not every plant likes the same soil. Soil is a mix of mineral material or ground up rock, often called ‘topsoil’ and organic material (things that were alive and are now dead) generally called ‘compost’. 

If possible, always source soil locally (if you live near an urban farm or an allotment, they might be able to help), and avoid anything that has peat in as it’s not a sustainable resource at all. If you can’t find topsoil, do not fret: you can mix some sharp sand with good quality compost (I particularly like New Horizon, Dalefoot compost made of sheep wool and bracken, and Moorland Gold that provide a sustainable alternative to peat) and you’ll get something decent. ‘John Innes number 2’ is an easy all-rounder as it is premixed and has the right amount of mineral and organic soil for most plants. Always start by filling the bottom 2 cm of your container with gravel, stones, broken crockery or anything that will allow drainage, then add your chosen soil mix.

Then, you want to match the soil to the plant you choose:

• Fruits (any ‘vegetables’ that contain seeds like cucumber, tomatoes, pumpkin, etc.), brassicas, potatoes, fruit trees and shrubs: you want a higher concentration in organic matter and adding some manure will help. Feeding regularly is a good idea
• Mediterranean herbs (basil, oregano, thyme): higher concentration of mineral soil (sharp sand or loam), less organic matter, and do not feed them - they like poor soil!

Choose the right plant

Your plant choice should really be based first on what you like; no need to grow kale if you can’t stand the taste. So the first step is really to narrow what you want (and possibly what you really don’t want!).

Then think about how much time you have to spend on your small garden. Salads and annual vegetables (they go through their life cycle over the course of a season) tend to require more care and a minimum of 2 or 3 weekly watering and pest checks - daily if it’s really hot. On the other side of the spectrum perennial plants (they survive for many years like trees, shrubs and some herbs) require less looking after once settled. You should still check on them and water weekly.

The depth of your planters and pots will also define what will thrive in them:

• Salad, brassicas, peas, beans, balcony carrots, radishes and mediterranean herbs can grow in as little as 15cm depth pots
• Beetroot, tomatoes, peppers, cucumbers and courgette will need a minimum of 40cm depth container
• Fruit trees and bushes, carrots, parsnips, comfrey and potatoes will need a minimum of 60cm depth container

So, what to grow? You can give most things a try, that’s the great thing with gardening. I’ve listed my top 10 productive plants for small spaces, but it’s just a start:

• Mediterranean herbs, especially rosemary, sage, thyme and oregano are amazing for pots. These perennial plants will last for years. They prefer poor soil (more topsoil than compost, and very little to no feed, don’t overwater), and will grow fine in medium size pots. They will thrive on a sunny balcony and will stay green all year round. You don’t need much for cooking, and they look lovely. They will flower during spring/summer, with flushes of gorgeous white to purple flowers very attractive to pollinators.
• Cut and come again leaves like oak leaf, mustard leaves, freckles, chard, beet leaf. They can grow in a small 15cm depth container and you can pick a few leaves regularly which is perfect to add to your salad bowl all summer. You can add some basil and flat leaf parsley to the mix for a really fragrant salad. Mustard and chard types are better early summer and autumn, while oak leaf and other lettuce do better in the summer. Leaf vegetables will do better in semi-shade. Always use a rich soil with more compost than topsoil and keep the soil moist.
• Peas are a delight for small gardens; they grow up and as such they save lots of space. Most varieties will crop over a few months, providing a steady stream of juicy pods. I particularly like sugar snap peas, snow peas and mangetout as they are best eaten whole with the pod when young. If let to grow, you can enjoy fresh peas straight out of the pod, so it’s a win-win situation. They like a fairly rich soil, and they will need a structure to grow on: netting or string and bamboo canes will do.
• Kales are a great addition to any small garden as they can be kept small and harvested young. I particularly like Cavolo Nero, Curly Kale and Red Russian kale. I have mine in a 20cm container and I crop a few leaves weekly. Go for a rich soil, and if their colour is off, add an alkaline solution (I use the cooled down water from boiling eggs, works a treat).
• A single courgette plant can produce a lot of fruits, and most courgette varieties will grow fine in a large enough container in a sunny spot. Make sure you use a rich soil with plenty of compost and some chicken manure mixed in. Pick a bush as opposed to vine type. I like 'Verde di Milano' or 'Burpees Golden Zucchini'. If you feel a bit more adventurous try a pattypan squash or a summer crookneck squash.
• Chilli are perfect for growing in pots on sunny windowsill or balconies. They don’t like big variations in temperatures between night and days so keep them sheltered and take them outside later in the year (no earlier than May). Use a rich soil and feed often. I like ‘Lemon Drop’, ‘Pretty in Purple’ and ‘Pyramide’ as they form compact plants that are well suited to containers.
• Small bush cherry tomatoes are perfect for balconies: they produce smaller plants that do well in containers, and their small fruits are more likely to ripen. Use a rich soil and put your pot in a sunny spot. I like all the ‘Tumbling Tom‘ varieties as they are really perfect for pots and will tumble down the side of your containers. ‘balconi’ varieties are just as great and come in red and yellow. Make sure you feed your tomatoes regularly and provide some support for the plant.
• Potatoes will grow well in containers. Make sure to earth them up: you need a big enough container, and use small potato varieties like ‘Charlotte’, ‘Jazzy’ or ‘Maris Bird’ better suited to containers. Use a potash rich feed for your potato plants throughout the season.
• Fruit bushes: currants, gooseberries and blueberries will do well in pots. Blueberries need an ericaceous (acidic) soil so they are really suited to pots where the pH of the soil can be managed. Make sure to net your fruits if you have a lot of birds around.
• Wild (alpine) and common strawberries will do great in pots, especially pots designed for extra productivity with multiples pockets. Strawberries are perennial so they will come back year after year.  Alpine strawberries are great if you have a semi-shaded space, while other strawberries will fruit better in full sun.

Happy growing!

Flexing your green fingers? Have a read of Julie's tips on gardening for wildlife, check out her website for more garden education or join a Capital Growth online session.