Spinach Growing Masterclass

Spinach is a winner thanks to its speedy growth, long list of health benefits and, of course, its plentiful harvests. Spinach can be tricky to grow unless you know the tips I’m about to reveal, but get it right and you can be harvesting bowlfuls of delicious leaves right through the year. Let’s go!

Where to Grow Spinach

I can’t think of many vegetables with as many culinary strings to their bow as spinach. Whether used fresh in salads, lightly steamed, whizzed up into smoothies or folded into soups and curries, spinach is up for it, which makes growing a few rows well worthwhile!

Spinach can tolerate light shade, and if you’re gardening in a hot climate then shade during the warmest parts of the day will be very welcome. Hot, dry conditions can cause plants to prematurely flower, or bolt, which means fewer, smaller leaves to pick – and we want to avoid that!

Make sure your soil is nicely rich – a barrowload of well-rotted manure or compost, applied during the winter (or any time up until planting) will give it a good start. A handful of a general-purpose organic fertilizer such as blood, fish and bone, scattered at planting time, will really supercharge growth.

Spinach is easy to sow direct where it’s to grow, but if you’re an impatient sort like me you can also sow them indoors in plug trays to get a head start on the season. When transplanting, space the seedlings about 8in (20cm) apart in a block formation. Make a hole for each seedling with a dibber or a trowel (or just your fingers), pop in the plant, and firm the soil down lightly around it. If it’s a bit cool or breezy at planting time, you can plant them a tad deeper, so the top of the hole helps to shield the young plant from the wind. Finish by giving your plants a good drink of water, ideally rainwater.

It’s tempting to think that you’re finished now but not so fast! Spinach seedlings are very attractive to birds such as pigeons early in the season, so covering them is a smart move. You can use a cloche or a row cover of garden fleece – making sure to remove it on hot days – or stretch netting over the bed, held up off the plants with canes. It’s important to stretch the netting taut to avoid birds getting trapped or tangled up in it.

Later in the season we’ll need to protect against slugs and snails too – more on that later.

How to Sow Spinach

I make my very earliest sowings of spinach at the end of winter, sometimes in milk jugs and kept outside before transplanting the seedlings into their own plugs when they’re big enough.

A more conventional way to start early spinach off is to sow into plug trays of screened all-purpose potting mix. Make shallow depressions into the surface of the potting mix with your fingertips before sowing two to three seeds into each. Cover over with a little more potting mix, and keep them in a greenhouse or cold frame until transplanting time.

The advantage of sowing into plug trays is that there’s minimal root disturbance. Just grow them on till they fill their plugs, then transplant them outside – there’s no need to thin the seedlings. If all seeds germinate, they can just go out as little clumps, no problem.

As well as getting a head start on the season, sowing into plug trays can also protect seedlings from attacks by slugs or birds, which is more likely early on in the season. And it means you can overlap crops, starting your spinach off while an earlier crop finishes off in the garden.

From mid-spring, once the soil has warmed up and dried out a bit, sowing direct outside is faster and more convenient because there’s no transplanting needed. Mark out rows in the soil around half an inch (1.5cm) deep, and space rows 8in (20cm) apart. For short rows, a bamboo cane is perfect for ensuring a straight row, but for longer rows you could use a stringline.

Drop one seed every inch (3cm) or so. If it’s warm and dry when you sow, water into the little trench you’ve made before sowing to create a nice, cool microclimate around the seeds. Cover the seeds with soil, and pat it down with the back of the rake. Give them a good drink of water to settle the soil in around the seeds.

Once the seedlings have popped up, remove any excess in stages until they’re about 6in (15cm) apart within the row. Don’t throw the thinnings away – they can be eaten as microgreens. Restaurants charge a small fortune for microgreens, but you can grow them youself for free!

Spinach also makes a fantastic container crop. Opt for a pot at least a foot (30cm) in width, and fill it with any quality, all-purpose potting mix. Scatter the seeds right across the surface, leaving about 3in (7cm) between seeds. Cover them with more potting mix and give them some water. There’s no thinning needing – just let them grow into a dense carpet of baby leaves for regular picking.

Growing Spinach

Spinach isn’t a fussy vegetable. Keep it free of weeds and well-watered in dry weather and plants will soon fill out. Consistent soil moisture is essential – these are leafy crops that lose a lot of water on warm days, so check regularly and give spinach a little extra water if in any doubt. Water in the morning if you can, so plants have plenty of moisture to draw on throughout the day as they put on growth.

Those luscious leaves won’t go unnoticed by slugs and snails. Pick off any you find, and set up defenses such as beer traps if you’re particularly slug prone.

Spinach can bolt (flower and go to seed) when planted early in the season, so avoid letting the soil dry out and protect them from very hot sun. It’s also worth seeking out bolt-resistant varieties that are slower to stretch to flower. This will prolong how long you can pick leaves, so here are a few variety suggestions to get you started:

Bolt-Resistant Spinach Varieties

• Apollo
• Celesta
• Correnta
• Lizard
• Medania
• Mikado
• Seaside
• Spinner
• Tyee

In very wet, humid conditions plants can become susceptible to mildew, a disease that turns leaves pale before making them die off. Proper spacing and regular picking will ensure good airflow between plants, reducing this risk. When watering, try to aim water at the base of plants rather than wetting the leaves, particularly on still, overcast, muggy days.

Spinach Alternatives

We’ll get onto picking those sumptuous leaves shortly, but first let me share a few spinach alternatives that are worth considering if spinach doesn’t grow well for you. These all have ‘spinach’ in their name, though they’re botanically unrelated.

First up is New Zealand spinach (Tetragonia tetragonioides). This soft-leaved, tender plant is a great choice for warmer climates and fares much better that ordinary spinach in full sun. If you suffer hot summers, this might be a good one to try.

Then there’s the really rather remarkable sprawling and clambering malabar or Indian spinach (Basella alba), which has fleshy, almost succulent leaves. Again, this is a solid choice for warmer climates.

Tree spinach (Cnidoscolus aconitifolius) is a taller plant with pink to red new leaves, while perpetual spinach is a fantastic choice for poorer soils and for cropping almost year-round.

Perpetual spinach (Beta vulgaris subsp. cicla) is more closely related to Swiss chard and grown in much the same way.

How to Harvest Spinach

Speed is a major selling point of spinach – as if it needed one! Start picking the smallest leaves for salads as soon as a month after sowing, or wait a few more weeks for good-sized leaves that are perfect for cooking.

I like to pass over my spinach rows every couple of days and take just a few leaves from each plant. This way I can make repeat pickings before plants inevitably bolt.

Bolting is usually what finishes play when it comes to spinach. Plants will eventually bolt, no matter how much you coddle them! For this reason, it’s worth making repeat sowings of spinach maybe once a month to keep those harvests coming, as this is a short-lived veggie. Once plants do bolt, just pull them up and throw them onto the compost heap.

Keep sowing throughout the growing season if your summers aren’t too hot. Make a final sowing in late summer using a winter-hardy variety to give a few leaves in autumn, and then more from early spring.

Winter-Hardy Spinach Varieties

• Atlanta
• Giant Winter
• Kolibri
• Renegade
• Rubino
• Space
• Sunangel
• Tragopan

If you’d like a planting schedule for spinach or indeed any crop, tailored to your specific location, check out our Garden Planner. Tinker with your garden layout to your heart’s content by taking advantage of our completely free, no-obligation, 7 day trial. If you’ve got any questions, just click on the Live Chat button to ask our experts.

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Spinach Grow Guide

Spinach (Malabar) Grow Guide

Spinach (New Zealand) Grow Guide