Spring’s well advanced here now, daylight is stretching into the evenings, it’s a lot warmer – and have you noticed how plant growth seems to be doubling by the week?
But if you’re worrying about falling behind already, please don’t! There’s still plenty of seeds to sow in spring: several summer staples, two of the most useful vegetable garden flowers, and my favorite leafy green of all – which isn’t just green, but a rainbow of cheer!
Sowing Sweet Corn
What do you reckon is the highlight of your gardening year? Picking the first pea pods? The first tomato? Or unearthing those gorgeous, smooth-skinned salad potatoes? They’re all up there, but for me it might just be sinking my teeth into a crisp, juice-popping cob of sweet corn. Yum!
Sowing sweet corn direct is nice and simple – there’s no potting mix needed, and it saves time potting on and transplanting. It’s simply a matter of sowing into warm, fertile soil. A position facing the afternoon sun is ideal, because corn loves plenty of sunshine and warmth.
Dib a hole about an inch (2-3cm) deep with your finger into loose soil. You can sow a couple of seeds in each hole and thin to leave the strongest seedling to make sure you get a plant at each position. Drop in your seed then cover it over. Space each seed about a foot or slightly wider (30-40cm) apart, in a grid pattern.
It’s really important to plant corn in blocks rather than long rows because it’s pollinated by the wind, so by planting in a block you’ll have more chance of success no matter which way the wind blows. Nighttime temperatures really need to be above about 50ºF (10ºC), so if it’s still a bit fresh at night, pop a row cover of garden fleece over the sown area to trap a little more warmth. Keep this in place for as long as you can to protect the young seedlings.
Now, having said all that, I’m not confident enough to sow corn outdoors direct like this. Spring where I live just isn’t reliably warm enough, so starting off this way risks patchy germination. But if I wait until later to sow, my corn won’t have a long enough growing season to produce a crop before the weather turns cooler, so I start the seeds in plug trays instead.
I like to use plug trays that are a bit deeper than usual to encourage deeper roots, which will help my corn seedlings be more self-reliant. Any reasonably deep pot would be fine – even toilet paper tubes. I add a handful of perlite to peat-free potting mix to help with drainage and keep it nice and light. Corn dislikes its roots being cold, claggy and wet, so it will appreciate a free-draining mix like this.
Simply push one seed per plug down into the potting mix to a depth of about half an inch (1cm). Place them on a sunny, warm indoor windowsill or on a heat mat to germinate. Once they’re up they can go out in the garden to grow on, initially under the warmth and shelter of a greenhouse or cold frame. Plant them at the same spacing as direct-sown seeds once there’s no danger of frost and the soil has warmed up a bit.
Don’t let your seedlings get root-bound in their pots. If it’s still too cold to plant when their roots have filled their containers, pot them on into bigger containers so growth doesn’t stall.
Sowing and Planting Climbing Beans
Beans, glorious beans! Again, you have two options – sow in containers away from the final growing area for peace of mind, or sow direct. I reckon beans are a safer bet for direct sowing than corn.
But why not sow into pots if it’s going to improve chances even a smidgen! Just like corn, beans grow fast and really prefer it nice and cozy, so it pays to get the conditions right. Of course, you could sow beans directly where they are to grow too – just wait til the soil’s nicely warmed up.
There are two main types of climbing bean you can start now – snap beans (aka fine beans, French beans or filet beans), and runner beans. The flowers alone make climbing beans worth growing – in fact, beans were originally grown as an ornamental plant rather than for their edible pods.
Push the seeds into their plugs to around a couple of inches (4-5cm) deep. Keep both beans and corn lightly watered once they’re up. Plant your beans against their supports after there’s no danger of frost, spaced about 6-8in (15-20cm) apart. Once they’ve started growing up their supports, top up the soil with a lovely mulch to keep the roots cool and moist – an essential consideration, because beans are very thirsty.
Growing Self-Blanching Celery
Do you have a vegetable that’s a bit of a thorn in your side – a nuisance-of-a-crop that’s always throwing up one challenge or another? Well, mine’s celery. I used to grow it no problem at all, but now it often gets ravaged by leaf miners.
Leaf miner pupae overwinter in the soil, so my trick for this season is to grow my celery well away from areas where I’ve grown it in the past to avoid the pupae finding my crop as soon as they emerge. I’ll also be growing them under insect mesh to stop the adult flies dropping by from elsewhere.
Moving things around a lot can get confusing, but the Garden Planner can help you keep a track of what you grew where in previous seasons. You can try it out for free – no payment details required.
Celery is less likely to bolt (flower and go to seed) if it’s sown when the weather is a bit warmer, so it’s important not to sow too soon. Earlier sowings can sometimes bolt because cold snaps trick the young plant into thinking they’ve been through a winter already, and the plants naturally want to flower in their second year. But if they do bolt, leave the delicate frilly flowers as a food source for the beneficial bugs.
Choose a self-blanching variety if you can, because that way there’s no need to make trenches or bank soil up against the stems to get those lovely crisp, crunchy stalks. By growing the plants fairly close together – around 9in (23cm) apart in a block formation – they’ll naturally produce blanched stems. It saves a lot of faff versus the traditional method. Self-blanching varieties include favorites such as 'Golden Self Blanching', 'Green Utah', 'Victoria', 'Granada', 'Celebrity', 'Loretta', 'Blush', 'Tango', and 'Tall Utah'.
Sowing’s super easy. Just sprinkle the seeds into a pot of pre-moistened seed-starting mix, then cover with clear plastic to keep it warm and humid. Tiny celery seeds need light to germinate, so there’s no need to cover them. Once they’re up and big enough to handle, carefully prick them out and transfer each seedling to its own plug.
Celery loves super-moist soil, so plant into enriched soil and keep it well-watered at all times. This a fantastic choice if you have an area to plant that tends to stay damp. They’ll also appreciate a good mulch as they get going to keep soil moisture locked in.
Edible Blooms
Still to come, my favorite leafy green…but first let’s give the bees something to buzz about with two easy-growing, always happy power flowers!
Beautiful Borage
The first time I grew borage I was amazed by how quickly it grew and how much our striped and fuzzy, buzzing friends loved the sky-blue blooms. And, as an added bonus, you can eat the flowers – they give a lovely refreshing quench to just about any summer drink.
Borage prefers sun but will do okay in dappled shade too. Start by forking over the soil to fluff it up, then sow the seeds lightly across the surface. Tickle them in with a rake.
The seedlings will need to be kept watered in drier weather, but the other great joy of borage is that’s it’s pretty self-reliant. It’s not an especially hungry plant, so it won’t need feeding, and it does well in slightly poor soils.
Reliable Nasturtiums
Another reliable annual flower that pollinators love is nasturtiums. Just poke seeds into the soil here and there where you want it to grow. You can get varieties that are quite compact, or trailing varieties that are great for sprawling down a slope or clambering up supports to add a beacon of color. You can eat peppery nasturtium flowers and leaves in salads, and even eat the seed pods in moderation, so they are a super useful flower.
I’ve had people comment that once you’ve introduced nasturtiums to the garden you’ll never be rid of them. And, certainly, I find it does self-seed pretty well and can grow very quickly. But this is a joyous plant that’s easily gathered up and pulled out where it’s not welcome. And just look at it – who wouldn’t welcome this sort of life-affirming cheer!
Colorful Swiss Chard
Swiss chard is my favorite leafy green – it’s a real winner with its seductive combination of luscious leaves and stupendous stems. Turn hard times into chard times with this easy-to-grow crowd pleaser!
There are two sowing windows for chard: in spring for leaves throughout the summer and into autumn, then again around midsummer for plants that will overwinter ready to launch into leaf production the following spring.
Like celery, a cold snap early on can result in chard bolting, so don’t be tempted to sow too early. Again, we have two options: sow direct, or into pots or plugs to plant at a later date.
Plant chard into soil that has been improved with organic matter such as garden compost. Lightly fork over the surface then drop two seeds into each position, setting each pair of seeds about 8in (20cm) apart. You will probably find that a few seedlings sprout in each position because each ‘seed’, as with chard’s close relative beets, is in fact a seed cluster capable of producing two or three seedlings.
My advice when growing chard is to choose a colorful variety – one with shocks of color to its midribs and veins. These types of chard look gorgeous, particularly when backlit in the morning or evening sun – food for the soul and the body in my opinion! Choose one color or a mix, which you can often find sold as ‘Rainbow Mix’, 'Bright Lights' or similar.
Keep your chard gently watered, and mulch the plants as they grow with garden compost and perhaps some dried grass clippings to protect and gradually improve the soil.
Now is a great moment in the sowing calendar. There’s still time to sow squash-family crops, broccoli, beets, and so many other vegetable garden staples. Check out last month’s sowing video if you missed it, because everything featured in that video is also good to sow now – see, you’re not behind after all!