Top 10 crops for your window box

Image: Windowsill Tomatoes

Don't have a garden? No problem! Even a window box or trough can produce a satisfying crop of home-grown produce. You just need to choose your fruit and veg carefully. If space is really limited, you can also grow microgreens and cress on a windowsill indoors.

According to our expert horticultural team, here are some of the best fruit and vegetable plants for small spaces and windowboxes:

1. Herbs
2. Salad leaves
3. Carrots
4. Sweet peppers
5. Chillies
6. Radish
7. Tomatoes
8. Strawberries
9. Spring onions
10. Rocket

1. Herbs

Chives have pretty pink blooms that pollinators love
Image: Chive seeds from T&M

Herbs are a great choice as they have a multitude of uses in the kitchen. Choose perennial herbs like chives, parsley and thyme for an attractive display. Alternatively, try a selection of annual herbs like basil and coriander. If you want to grow mint, dedicate an entire box to this plant as it will grow rapidly and overwhelm other plants surprisingly quickly!

2. Salad leaves

This tasty mix includes a blend of flavours and colours
Image: Salad leaves 'Speedy Mix' from T&M

Salad leaves are easy to grow in a window box, and a great choice if you fancy snipping a few leaves into your sandwich! Choose a 'cut and come again' variety that can be harvested a few leaves at a time like 'Speedy Mix' or 'Nice 'n' Spicy'. Both of these can be direct-sown from seed. Alternatively, try ordering some 'Little Gem' plants to pop into your container.

3. Carrots

These bite-sized carrots are ideal for containers and window boxes
Image: Carrot 'Paris Market – Atlas' seeds from T&M

You might be surprised that you can grow carrots in a trough or window box. However, it's important to choose the right variety as traditional, long, slender carrots will quickly run out of space in the confines of a container. Carrot 'Paris Market – Atlas' produces short, rounded roots that don't need particularly deep soil to mature. These can be enjoyed as a tasty snack or eaten as 'baby carrots' alongside your favourite meal.

4. Sweet peppers

These compact plants produce over 50 peppers each
Image: Sweet Pepper 'Virtue' plants from T&M

Sweet pepper plants grow well in a windowbox provided they have a sheltered, sunny spot. Opt for a compact variety like Sweet Pepper 'Mohawk' which will gently trail from your windowsill or hanging basket. Or for something a bit unusual, try Sweet Pepper 'Flamingo' which produces sweet, crisp fruits that cycle through yellow, apricot and orange before maturing to dark red. Simply harvest when they reach the colour that most appeals to you.

5. Chillies

This highly decorative chilli pepper is perfect for windowboxes and containers
Image: Chilli Pepper 'Basket of Fire' F1 from T&M

Chillies are a fantastic choice for a sunny outdoor windowsill, as well as being an attractive addition to your garden. If you start your chilli seeds early enough, these plants offer a cost-effective way to enhance your home's kerb appeal while spicing up your home cooking. But don't worry if you've missed the sowing window. Order plants instead - a compact variety like Chilli Pepper 'Basket of Fire' will fill your window boxes with instant wow-factor.

6. Radish

Image: Radish 'French Breakfast 4 - Francis' seeds from T&M

These quick-growing roots are perfect for adding a crunch to your salads. If you sow the seeds little and often, you'll have an ongoing supply throughout the summer and into autumn. Opt for a short, rounded variety like Radish 'Poloneza', or the super-speedy 'Rainbow Mix' which is ready to harvest in just 28 days. Traditional favourites like 'French Breakfast' also grow well in window boxes, especially in slightly cooler spots, where they're less likely to run to seed.

7. Tomatoes

This compact variety is attractive and high yielding
Image: Tomato 'Balconi Red' seeds from T&M

Modern breeding has developed some superb dwarf bush tomatoes that make excellent window box crops. The easiest way to grow tomatoes in window boxes is to buy a few plants: Tomato 'Magnusa' produces vast numbers of sweet cherry tomatoes and requires no side-shooting or pruning. Tomato 'Tiny Temptations' is another good option for window boxes and troughs, tumbling over the edge to create an attractive display. Always keep tomatoes well-watered and feed your plants regularly to get the best yields.

8. Strawberries

This everbearing variety produces lots of bright, sweet and juicy berries in a small space
Image: Strawberry 'Flamenco' (everbearer) from T&M

These easy-to-grow fruits are perfect for troughs and window boxes, producing sweet juicy fruits and a pretty display of flowers too. Strawberry 'Albion' is an everbearer variety that produces dark red berries from June to October. Alternatively, choose a combination of early and late season strawberry plants to provide a steady supply of fruits throughout the entire summer.

9. Spring onions

'Totem' has straight stems that don't bulb
Image: Spring Onion 'Totem' seeds from T&M

For a quick-growing, low-maintenance crop that can be grown in the smallest of window boxes, spring onions are an excellent choice. Easy to grow, simply direct sow the seed throughout spring and summer for a continuous supply of tasty scallions. Try Spring Onion 'White Lisbon' for punchy flavour, or Spring Onion 'Totem' which produces long, bulb-free stems that won't need thinning.

10. Rocket

For a flavour-packed, easy-to-grow salad leaf, you can't go wrong with rocket.
Image: https://www.thompson-morgan.com/p/wild-rocket-seeds/705TM

Regular rocket (Eruca vesicaria subsp. sativa) like 'Discovery' has a unique aromatic taste that's popular in salads and sandwiches. Wild rocket (Diplotaxis tenuifolia) has a stronger flavour and attractive deep green, serrated foliage that can be eaten raw or treated like spinach. Both are ideal for window box or container growing.

We hope this helps you to keep your window boxes filled with attractive and edible crops throughout the year. Find more ways to make the most of a small space garden in our guide to growing berries in pots and containers and our herbs masterclass.

Written by: Sue Sanderson

Plants and gardens have always been a big part of my life. I can remember helping my Dad to prick out seedlings, even before I could see over the top of the potting bench. As an adult, I trained at Writtle College where I received my degree, BSc. (Hons) Horticulture. After working in a specialist plantsman's nursery, and later, as a consulting arboriculturalist, I joined Thompson & Morgan in 2008. Initially looking after the grounds and coordinating the plant trials, I now support the web team offering horticultural advice online.