10 Veg Seeds You Should Sow In June
June ushers in Summer and brings us the longest days of the year. The weather isn’t too desperately hot (for us temperate Brits at least) and the air is still full of moisture that can fall and work its way into the soil. That means this month has the perfect growing conditions for so many plants and there are lots of veg seeds to sow June.
If the year had more than 12 months you could start just about anything now (whichever side of the world you lived on) but it’s starting to get a little late to grow peppers, aubergines and bigger tomato varieties from seed – those you’ll need to buy from a garden centre.
For everything else, try growing the vegetables below from from seed – I’ve included links to some varieties I’ve grown before. Or if you’re pushed for time, you can watch this video of my Top 3 Seeds To Sow In June.
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1. Sweetcorn
June is a great time for sowing sweetcorn. The frost risk should have passed which means you can direct sow sweetcorn in most areas. Sweetcorn dislikes being transplanted which makes late May & June the best time to get sowing so you can enjoy freshly barbecued sweetcorn later in the summer.
That being said, I tend to start my sweetcorn inside using the paper towel method to ensure germination and then I’ll go outside place the seed and its single root in holes I make with my dibber. Sweetcorn is best grown in dense blocks because it’s wind pollinated and if any ears of sweetcorn are too isolated, the tassels won’t get fertilised and you’ll have missing kernels in your cobs.
I plant my sweetcorn in 45-60 cm spacings but I plant them in a hexagonal arrangement to fit the maximum number of plants in by increasing the planting density (and hopefully improve pollination). It’s a bit nerdy but if you take a regular grid and offset a row by half a grid spacing and then bring the rows together a little, you can then make the grid smaller without the plants getting closer (it’s just Pythagoras) and achieve the maximum density. The theory is for spheres and disks but I suspect it works for plant root spread too and you can squeeze a few more plants in but being more densely packed should help you get perfectly formed cobs.
Varieties like Conqueror (F1) taste great, Swift* will be ready for harvest very quickly (as the name suggested) and Glass Gem* produces traditional multicoloured cobs and store and grind well.
Read this article to find out everything you need to know to grow sweetcorn from seed.
2. Carrots
Carrots are definitely not my favourite food but after having my first glazed Chantenay carrots at a work Christmas dinner, my view of them completely changed. They are much shorter than regular carrots and I guess that makes them a lot sweeter and therefore much more palatable.
Varieties like Chantenay Red Cored* can be grown in containers which makes harvesting much much easier. Growing in containers also means you can avoid carrot fly issues as, despite the name, they aren’t great at flying and a tall trough will help keep them out. You can also lift the container indoors when it’s time to thin your carrots so that the smell doesn’t attract the pests or you can go one step further and germinate your carrots indoors under cling-film and then relocate the container outside after the seedlings emerge and have been thinned.
3. Cauliflower
Cauliflower makes the list for June because it’s getting to the end of the sowing window so you’ll need to get your boots on and sow them quickly if you want a harvest this year. Otherwise you can wait until the autumn and harvest in the Winter.
Cauliflower also tends to bolt if it gets too stressed by the heat and that’ll be more likely if the plant is immature. So sow your seeds in the first week of June if possible and hope for cooler weather. I usually sow one seed per pot and then transplant the seedlings into my no-dig begs (plants should be spaced 45-70 cm apart) but you can also direct sow them in drills less than an inch deep and cover with a fine layer of compost or coir and thin them out as needed.
I absolutely love Romanesco Precoce* because of its beautiful geometric florets but it also has a nutty smell and taste and you should be able to harvest towards the end of the year. It might struggle in a very wet or cold winter but you could also harvest some early next year.
It’s a similar story with Di Scillia Violetto* which grows deep purple heads while varieties like All The Year Round* are cold hardy and make better winter harvests, although you can save sowing these until after the worst of the hot weather has passed if you prefer
4. Beetroot
June is a great time for sowing beetroot seeds. For me, that’s mostly because the start of the year is overloaded by tomatoes, peppers and plants with a long growing season, but also because this plant can be harvested before bolting becomes an issue – sometimes as quickly as 40 days.
Old and woody roots don’t taste as good as the fresher younger ones so late spring and summer are a great time to start sowing and, as they are hardy, you can keep growing them through the winter too – although expect production to slow.
You can sow beetroot direct or indoors – dealers choice, I don’t find much of a difference – and you could probably even grow them entirely in containers too as their footprint is very small. Harvest them when they somewhere between the size of a ping-pong ball and a tennis ball.
You can grow varieties like Bulls Blood* which is grown primarily for its gorgeous deep red leaves, which are also edible. Or you could grow varieties chosen for their bulbs like Chioggia* which is an Italian heirloom variety with very distinctive pink rings running through its core.
5. French Beans & Runner Beans
French beans and runner beans are completely intolerant of frosts which means most gardeners in the UK need to wait until the end of May or June to plant out their climbing beans. You can start plants indoors earlier but I find it only takes about a week, maybe two, before they start to get too big for their pots and need something to climb up. It’s also commonly said that they don’t like having their roots disturbed at all which is why many gardeners chose to direct sow at the start of June.
I personally prefer to germinate indoors in coir and then move the sprouted seeds into holes in the ground made using a dibber, situated at the base of bamboo poles that the beans can climb up. The suggested spacing is 45 cm for climbing beans and 30-45 cm for dwarf or bush varieties but I find you can afford to bring them closer if necessary – in my first year of growing I put them about 20 cm apart in the corners of plastic moving boxes and four boxes gave me more pods than I could ever eat.
Be sure to harvest the pods when they are young so you can enjoy the best texture and encourage even more pods to form. You could also grow beans to store over winter but if you’re short on space, I’d opt for enjoying the fresh pods and blanching & freezing any excess.
Last year I grew french bean varieties like Blauhilde* which produces cylindrical purple pods and Neckargold* which produces flatter yellow ones but there are so many other colours and shapes and textures to choose from, Scarlet Emperor* (green, runner), Borlotto* (red, dwarf French) and Cobra* or Python* (green, French) being quite popular.
6. Chard
Chard is probably the most under-rated plant in the veg patch. I think it can stand up to ornamental plants and, on top of that, the entire plant is edible. The leaves are crunchy and firm, making them great burger fillers or spinach replacements (perpetual spinach is closely related), the stems are chunky and earthy, making them a celery alternative (but with good taste) and great for bulking out stews, and the root is edible too – apparently tasting similar to beetroot (again, being closely related). Chard is also a ‘cut-and-come-again’ plant, re-growing stalks that you pull away, and it’s very cold hardy, meaning one plant could keep producing for 18 months.
Chard should be sown continuously through the summer because plants can be prone to bolting when stressed by heat and drought and will need replacing. I like to let one or two plants go to seed because they form spindly, alien-like plants, which make a great focal point through the late summer and into the winter. The ones that don’t go to seed or the replacement plants you grow, will keep you fed through the winter.
Rainbow Mix* and Bright Lights* are the most common varieties you’ll find and I like to allow 45 cm between plants, as the leaves do tend to quickly fan out and they do so quite significantly too. Pull leaves to eat from the bottom and they’ll keep getting replaced as you work upwards.
7. Summer Squashes
Summer squashes are quick to grow and they can be eaten while immature, meaning that you can get a relatively quick harvest from them.
You can start them earlier in the year in pots so that they produce throughout the entire summer (as the name suggests). But as they are another annual plant that’s unable to withstand any frost and dislike their roots being disturbed, I don’t normally recommend that until late May at the earliest and June is the perfect time to sow some more and get them in the ground.
They come in all shapes and sizes from the small round compact Summer Squashes* pictured above to the outrageously elongated Tromboncino*. Squashes left on the plants will ripen, develop thick skins and store for a long time and varieties of winter squash like Butternut Squash are grown for this reason, but the immature fruits are often still edible so you may find some great storers that taste great young. However it tends to be the case that summer squashes don’t have a long shelf life (this is the main distinction between the two groups of squashes) so it’s best to eat them fresh if you can. The good news is that this means summer squash plants will produce more fruits than winter varieties if you keep on picking them young.
8. Courgettes (Zucchini)
Yes, okay… These are technically summer squashes too but they get their own listing here because they’ll probably get their own shelf in the fridge by the end of the month if you aren’t careful!
These are very prolific croppers and, if your diet was 100% courgette, a few plants could keep you fed all summer. If you went big on the spiralizer craze of the mid-2010’s, then you and your long-suffering family are in for a courgetti-shaped treat. In other parts of the world they call them Zucchini and miss out on this delightful name for the spaghetti substitute and, instead, they have to settle for ‘zoodles’…
They might produce a lot of food but they are also heavy feeders, so space out your plants and top up your garden beds with compost before planting. If you’ve got a patch of lawn that is looking bare then consider putting down a one square metre piece of cardboard, piercing the centre, covering with compost, planting a courgette plant and turning that unproductive patch into a backyard gold rush.
Which is apt because Gold Rush* is a great variety producing inordinate amounts of delicious yellow fruits and varieties like Black Beauty* produce very dark green courgettes.
9. Winter Cabbages
May and June are the best months for sowing winter cabbage. The young seedlings aren’t big enough to bolt and go to seed under the heat pressure during the height of the summer and can grow big and and robust in time for winter. You’ll need to cover them to avoid caterpillar issues later in the year but otherwise if they are planted in part-shade, they’ll do fine and give you harvests from December onwards.
You’ll need to ensure that you use cold-hardy Savoy varieties like January King* and Tundra*. You can start in pots or sow direct into shallow drills about 20 cm apart. It’s common to start plants in a separate seedbed before transplanting cabbage plants into their final position but that sounds like a lot of work so I’ve not tried it.
When grown, the cabbage heads can be left on plant for several months and cut off of the plant when needed. If you spread out your seed sowing then, in principle, it’s possible to have a supply of cabbage all year round. Oh and the rest of the plant is edible too!
10. Rocket (Arugula)
And last but not least we have my favourite salad leaf – although, being so low on this list, you can probably tell that I’m not a leafy green guy.
Rocket (or Arugula) is a fast growing salad leaf which comes in both wild and salad varieties. Wild rocket* is a perennial that keeps coming back year after year (even through the record cold spell of 2022 which went down to -10°C, it’s super hardy!) and it only gets spicier each time. And much like basil and tomato plants, it releases a distinct smell when you brush past it. All of these benefits along with it’s unique spiky shape make it my favourite salad leaf to grow.
You can also get tamer cultivated or salad rocket seeds*. They are less robust than the wild kind and the leaves are frillier but all of the plant is a little easier on the tongue. I’ve not had much experience with this kind as I started by scattering wild rocket seeds and creating a patch that seems to keep growing back and even self-seeding here and there throughout the garden.
In my first year of growing, I had a problem with flea-beetle through the middle of the year so dot this around the garden and either plant sacrificial plants nearby to protect the rocket or use rocket to protect your most prize crops.
And Many More
June really is an exceptional time of year. As well as the above, you could be sowing so much more including peas, spinach, lettuce, kale and other salads to replace the ones that might begin to struggle in the July heat, and you could be putting in more potatoes, herbs like basil to plant between your tomatoes, and edible companions like nasturtium and marigolds. And you can keep sowing fast growing crops like radishes and harvesting until the year is out.
Happy Gardening!
