Starting an edible windowsill garden: step-by-step
Just because you don’t have any outdoor space doesn’t mean you can’t satisfy your green-fingered tendencies. Our step-by-step guide to starting an edible windowsill garden will have you up and running before you can say “loose leaf lettuce”.
5 minutes to read
What do I need when starting an edible windowsill garden?
I know that a lot of you will already have some gardening supplies to hand, but if you’re starting an edible windowsill garden from scratch, here’s a comprehensive list of everything you’ll need:
- First on the list, and the most important; you’ll need a nice, sunny windowsill. One that gets at least 4 hours of sunlight per day (preferably more) is best.
- A selection of pots and containers with good drainage holes. I’ll cover exactly the kind of containers needed for specific plants later in this post. A good starting point though is some cardboard toilet roll tubes and a tray, and some sustainable pots such as clay or bamboo. Alternatively, we love this idea for recycled tin can plant pots.
- Peat-free potting compost. Why peat-free? The RHS has a great article explaining why more gardeners are turning to peat-free potting products.
- Seeds or small plants
- Fertiliser – see individual instructions for specific fertilising instructions.
- Water (and a good memory or reminder on your phone so your new garden never dries out).
What should I grow when starting an edible windowsill garden?
As we always say here at Ailuna, start small! Don’t try growing 20 things all in one go because you’ll probably run out of steam. So pick two or three from the list below and see how you go. Remember, some won’t succeed the first time around so keep trying or select something different. You’ll soon find your groove (and the things you love harvesting and eating the most.)
Starting an edible windowsill garden – easy to grow ideas
How to grow lettuce on your windowsill
Check the pot and put water in the saucer if the soil starts to look dry. Germination usually takes 10-14 days.
Rotate the pot daily so your seedlings get an even amount of light and harvest the leaves when they are 10-15 cm tall.
How to grow pea shoots on your windowsill
Pea shoots have a deliciously delicate flavour and are perfect in salads and stir-fries.
Soak your seeds in water overnight and then sow them in a low tray with a peat-free compost, fairly close together. There is no need to cover the seeds as they can germinate sitting on top of the compost. Water very lightly and cover the tray with a piece of cardboard or equivalent to exclude a bit of light. Keep them slightly moist and warm and in 3-4 days you should see little sprouts appearing. Remove the cover and place it on the windowsill. You can harvest and enjoy them when they reach about 15-20 cm tall.
How to grow tomatoes on your windowsill
If you’re starting to grow tomatoes in your edible windowsill garden, you’ll need to sow seeds in March. If it’s later in the year, though, you can always buy starter plants instead of seeds to give yourself a headstart.
For indoor growing, it’s best to choose a dwarf variety such as minibel. They produce lovely bushy plants that can support themselves so there is no need for canes.
If you’re using seeds, sow them initially in small pots. Toilet roll tubes are great because they allow you to avoid disturbing the roots when you move the plants into bigger pots later on.
Sow them 2 cm deep in moist compost in a warm spot – tomatoes love heat to germinate. Keep the compost watered and grow the plants in the toilet roll pots until they have 3 true leaves. Then carefully remove the paper (slice or cut carefully and not too deep into the compost) and repot into a 10 cm diameter pot. When the plant has grown nice and strong, move it into the biggest pot your windowsill allows. Your tomatoes should be ready to harvest between August and October. If you have space, you can also move your tomato plants outside in a sunny spot once they’re strong enough. Start feeding you tomato with a tomato fertiliser when the second flower truss* appears.
*A truss is a group of smaller stems on your tomato plant, where flowers and fruit develop.
How to grow spinach on your windowsill
Spinach doesn’t need quite as much sunlight as most of the other plants on this list, so if you have a windowsill that only gets morning sun, this is for you!
You should sow the seeds 1 cm deep and 5 cm apart, or use toilet roll tubes again so you get individual plants. It’s important to use a well-draining soil and not to let it get waterlogged because spinach is not a fan of too much water cramping its style.
It’s also a good idea to feed your plants once a week with a high nitrogen feed, to keep them strong and healthy.
When your spinach has 5-6 leaves, you can harvest some of the outer ones whilst leaving the ones in the centre to keep growing.
How to grow chillies on your windowsill
Fancy a spicy little number to pep up your cooking? Then chillies are a great addition to your new windowsill garden.
It’s a good idea to choose plants with smaller fruits such as birdseye for a nice, sunny windowsill – chillies like warm conditions to thrive. Sow a few seeds 1 cm deep in your new favourite plant pots – toilet roll tubes, or in a 10 cm pot. Like spinach, chillies like soil that drains well. Even though they like it hot, make sure you don’t let the compost dry out completely. You can create a hot, damp environment by placing a plastic bag over the pot and fastening with an elastic band.
If you sow more than one seed in the pot, you should re-pot into individual 10 cm pots when the seedling reaches 3-4 cm.
When you can see the roots in the drainage holes at the bottom of your 10cm pot, you can repot into an 18-20 cm pot and watch your plants flourish! When the plant is 20-30 cm tall, pinch out the growing top to encourage branches.
The plant will flower and produce chillies through the summer. Feed weekly with a multipurpose fertilizer to keep them in tip-top condition. Bonus hint: remember that you can dry the chillies if you end up with too many.
How to grow garlic on your windowsill
This is probably the one requiring the least time and effort because you can just re-grow from a bulb of garlic you’ve bought from the supermarket! Break up the bulb into cloves and plant them pointy end up, evenly spaced out in a pot. Keep them moist and once in a while, you can snip 5cm off the leaves, to use in salads or sandwiches. Leave them to grow until the leaves dry up, then dig up and harvest the garlic bulb.
If you’d like to know more about regrowing food from scraps, our recent post on reducing food waste will be right up your street.
How to grow basil on your windowsill
Basil needs a lot of sun to grow indoors. Using a small pot or your trusty cardboard toilet roll tubes, sow your seeds sparingly. Basil likes to have plenty of personal space so avoid overcrowding. Our resident windowsill gardening expert Helene has found that 1-2 plants in a 15-20 cm pot over summer is enough. Cover the seeds with a thin layer of soil, press down to firm the soil, and then water. Because the seeds are so small you can also use a spray bottle to water them in.
Cover the pots with a plastic bag, or if you are producing many seedlings you could invest in a small propagator which is like a windowsill-sized greenhouse that can be reused year after year.
Place your pots or propagator on the sunniest windowsill you have and in 7—14 days you will see small seed leaves appearing.
When the seedling has 2-3 sets of true leaves you can start pinching off the topmost leaves and stems (and eating them) to promote more growth and a bushier plant. Pinch off any flowers too, to keep your plants from going to seed.
How to grow parsley on your windowsill
Start by soaking your parsley seeds overnight, then sow 2-3 seeds in a toilet roll tube, with soil just covering the seed. Contact with the soil is important, so firm it down to aid germination. Water the seed in or use a water spray to keep the soil moist.
Cover the tubes and be patient while the seeds work their magic.
Start to fertilise with a weak multipurpose solution when the seedlings have true leaves. Most parsley plants will be ready to start harvesting after 70-90 days – make sure you cut from the leafy stems at the bottom of the plant to promote further growth and a larger plant
Looking forward to starting your edible windowsill garden? Show us your seedlings!
We’re very lucky in the UK that it’s possible to find and eat locally-produced fresh food all year round. Even in the middle of winter!