When and how to start growing food in pots on your patio or balcony

Common questions, pitfalls to avoid, and tips to help you make a successful start.

I often chat to people who love the idea of growing food in pots on their balcony or patio…. But, for a variety of reasons, don’t get round to it. Some are worried that they don’t know enough to be successful, others that they lack the time, or don’t know what to grow first or lack confidence after an unsuccessful growing experience (I think we’ve all had at least one of those!).

If you like the idea of growing and would like to start, I hope this post will:

• Help answer some of the common questions.
• Guide you towards the best time to start.
• Help you avoid the most common pitfalls.
• Reassure you that it is worth giving it a go!

Let’s start with the common questions.

How much sun and space do I need to grow in?

You will need a space outside (ideally) that gets at least three hours of sun a day.

A balcony, patio or yard is ideal. If you don’t have your own, you might find an alternative nearby: I’ve seen people grow in neighbours' front yards, empty parking bays, communal courtyards, even their local churchyards.

A space doesn't need to be large to be worth growing in. A window sill can become a mini herb garden - the photo above shows one I made on my kitchen windowsill in London. A square metre / yard is enough to grow a significant amount of salad. In a larger space - like a patio or large balcony - you might be able to grow all your herbs, salad, and a significant contribution to your veg and fruit needs.

How much time do I need to look after it?

One of the beauties of container gardening is that you can have as many or as few containers as you have time to look after. And you can adjust the number accordingly.

On the other hand, plants in containers do need watering most days from late spring to late autumn / fall. This doesn’t need to take long. The secret to container gardening is little and often.

With the right mindset, watering can also be a rejuvenating interlude in the day - a moment to reflect after breakfast, or a welcome excuse for a screen break if you’re working from home.

How much time do you need to maintain a container garden? It depends on what you grow (some plants are lower maintenance than others), if you have a tap or water butt near your plants (this cuts watering time significantly), and, of course, how many pots you have.

For example, five to ten pots of Mediterranean herbs like sage and rosemary can be watered in five minutes or less, and require minimal maintenance, perhaps just an hour or two in total over an entire year.

A more substantial garden of say twenty pots - filled with a variety of herbs, salads and veg - might take ten minutes each day to water, plus an hour once every couple of weeks between April and September to sow new seeds, tie up and maintain. You probably will also need one or two half day sessions each year for more major jobs like setting the garden up at the start of the season and tidying up at the end.

The nub of it is that container gardens do not need to take up a lot of time, but they do need a few minutes on most days from late spring to late autumn / fall.

Before I added this water butt to my London balcony, I had to fill a watering can from a tap inside. It made watering much quicker - and less messy!

When’s the best time to start growing?

Each year it can seem like everyone is sowing seeds in March and early April. But early spring is NOT the best time to sow if you are new to growing. Seeds are reluctant to germinate in the cool temperatures and seedlings struggle to grow strong because light levels are often too low for them.

It gets much easier as temperatures warm and days lengthen in late spring and early summer. Everything just grows quicker and stronger, making for a more rewarding and motivating gardening experience. This is what you want!

The best time to start? As a general rule, it’s safest and easiest when the risk of frost is past and when night time temperatures are regularly getting close to 10oC / 50oF. In cooler areas (like the North East England where I live), this is often late April to mid June. In warmer cities (like London, Madrid, New York and San Fancisco), it will be a few weeks earlier.

If you miss the late spring window, July, August and September are also good options for starting. It remains warm and light in most areas, and there are still things that can be sown and grow easily at this time in most areas.

How many containers should I start with?

As many as you like! Even just a handful of pots with herbs will add greenery, be fun to grow, and will add flavour to your meals on a regular basis.

If you have enough space, ten to twelve containers is often a good number to start off with. As this enables you to grow a selection of plants, and discover which grow well for you and which you most enjoy growing and eating. But it won’t be too onerous either.

You can then add more containers each year as you learn, evolving your garden as you discover what you like to grow and how much time you want to put into it.

What are the most common pitfalls to avoid?

While there are a myriad of things that can go wrong in gardening, nine out of ten times a problem in a container garden is due to one of just five things. These are all easy and common mistakes for beginners to make - but also more easily avoided if you are aware of them.

1. Growing in too little sun

Some vegetables like chillies and tomatoes need a lot more sun than others. Most edible plants need a minimum of three hours sun to grow healthily. In less sunny spaces, most leafy crops (salads, herbs, spinach, kale etc) and woodland fruits (blueberries, blackberries etc) are good to try first. I’ll a write a more detailed post on this topic soon.

Most leafy greens will grow in just three or four hours sun - and microgreens like this can sometimes be grown in just one or two.

2. Using too small a pot

The general rule is that plants grow bigger and stronger in larger pots - and the bigger the plant you are trying to grow, the larger the pot you need. Most herbs are fine in 2 - 10 litre / ½ - 2 gallon pots, salads will do OK in window boxes, larger vegetables like tomatoes and French / string beans are better in something of 20 litres / 4 gallons or larger.

It is possible to grow in small pots: you see lots of images of plants in yoghurt pots on social media. But it is much easier and less work to grow strong plants in larger pots.

3. Forgetting to water

It’s so easy to do this, particularly if you’ve not grown before. Most plants in containers need watering once a day in warm or windy weather. The best way to remember is to try to fit it into your daily routine, perhaps after breakfast or when you get back from work. A note on your fridge or a daily reminder on your phone can be helpful if, like me, you are prone to forget.

My first attempts at growing were severely hampered by forgetting to water. The solution that worked for me, ironically, was getting more plants - as this motivated me to look after them better.

4. Using poor quality compost / potting mix

The compost / potting mix is as important as the foundations of the house. It’s essential for strong, resilient plant growth. The problem with the cheapest brands is that they tend to be more inconsistent - sometimes OK but the chances of a poor bag are high. What’s available varies from shop to shop and region to region. Ask for advice in a good independent garden centre or from other gardeners in your area to find a good one. All you need is a good quality multipurpose peat free compost or potting mix.

5. Not feeding

As a very rough rule of thumb, a new bag of potting mix will contain enough food for around six to eight weeks. After that, your plants will need feeding for optimum growth. My book, the Vertical Veg Guide to Container Gardening, goes into detail over 13 pages on what and how to feed container plants. However, you don’t need all this information to make a successful start - sometimes keep everything simple is the best way to get going. If you just get liquid tomato feed for all your fruiting crops and a general purpose organic liquid feed like Nugro for everything else, your plants will grow stronger and yield more.

What do you need to invest in?

Two things in particular I recommend not skimping on:

1. A good quality peat free potting mix / compost (see above).
2. Fresh seeds from a reliable seed merchant. Look for one that sells seeds grown in the region or country you live or one that professional organic growers use. In the UK, good choices include Vital Seeds, Reel Seeds and Tamar Organics.

Good quality organic feeds are also a good investment. You’ll need a tomato feed if you are growing anything that fruits. And a general purpose liquid feed, like liquid seaweed (or the Nugro mentioned above), for your other plants.

If you are looking to cut costs, recycled containers like old veg crates, recycling bins or the plastic buckets flower sellers use are a good option. Keep an eye out as these often turn up when you’re not looking.

You’ll get more choice in terms of aesthetics and size if you buy your containers. Remember that larger containers are generally easier to grow in - although they are also heavier and need more potting mix to fill. Avoid the flimsy cheap plastic containers, often sold in budget stores, as these quickly become brittle and crack. Also avoid the small terracotta pots as they dry out too quickly - the larger ones are OK though, particularly for Mediterranean herbs.

As you gain experience in growing, you will discover more ways to cut the cost of growing. You can save your own seeds, make your own organic fertilisers, and grow plants from cuttings, for example. But often it is best to take things one step at a time and learn new things as and when you feel ready.

Good quality compost / potting mix underpins successful container gardening

I don’t know enough - how do I learn?

People often delay growing because they think they need to know everything before they start. But the good news is that the basics of gardening are simple and you don’t need to know much. Put a seed in good soil with enough sun and water and it will normally grow - in essence, that is all there is to it.

That said, a little bit of the right information can make a big difference - like being aware of the common pitfalls listed above. But you really don’t need to know a lot and you will learn so much by actually growing. Everyone has different learning styles but often it makes sense to start growing as soon as you can and to learn as you go.

How do I start?

The best way to learn is often to give it a go with an open mind and a relaxed attitude - and not to worry if things don’t all work out. Try to see it as a learning experience, as a fun adventure into the unknown.

Decide what you want to grow, when you want to start, gather the pots, seeds and potting mix you need and put a date in the diary to get it all set up!

In my next post we’ll look at some of the edible plants that are easiest to grow first - although few plants are too difficult, provided you can offer them the warmth and sun they need.

Your questions? Your experience of starting? 

If you are hoping to start growing this year, what other questions do you have? More experienced gardeners: do you have any other advice or observations you can offer those wanting to grow?