Spinach is a really wonderful vegetable that has a variety of uses and is super healthy. But is there a secret to growing spinach without bolting?
If you have ever grown spinach during summer, you probably encountered the problem of bolting (which means the plant sets seeds).
It’s annoying when this happens, because it means that you will have no more crops, as the leaves will taste bitter and no new leaves will grow.
Bolting is a very common problem with spinach but in this article I will tell you how growing spinach without bolting is possible, even in the hottest of UK summers.
If you know all about starting spinach from seed and just want to know the secret to preventing bolting, go straight to How To Grow Spinach Without It Bolting.
How To Grow Spinach From Seed
If you want to know about growing spinach without bolting, you first have to know how to grow spinach.
Choosing Your Variety
When growing spinach, the first step is to select the variety that suits your needs. Modern F1 hybrids are often very quick growing but produce a crop over a short period.
Heritage varieties are usually slower growing and produce a crop of leaves over a longer period.
There are also cultivars that are bolt resistant, which means they are less likely to bolt early, for example, Missouri and Amazon.
Sowing Your Spinach Seeds
Spinach likes to be sown in soil that is rich in organic matter and holds moisture. Add 2.5cm (1in) of rotted manure to the bed at least two weeks before planting.
Seed sowing can begin as early as February if some protection in the form of cloches or a fleece is provided. The main sowing season begins in March and continues until late September.
A break from sowing should take place in June and July as plantings in these months will go to seed quickly.
The seeds should be sown thinly less than 2.5cm (1in) deep in rows that are 20cm (8in) apart.
Germination should take 5-7 days. Keep sowing seeds every 4 weeks to get a year-round crop.
Spinach Plant Aftercare
After germination, the plants should be thinned to 7.5cm (3in) apart.
Small spinach plants are like magnets for birds who will eat the seedlings to the ground. Covering with a net for a few weeks after planting to prevent any problems is worth the effort.
The first four weeks after germination are usually a good time to weed the plants. After this, the leaves should have grown a canopy which will stop any new weeds growing.
Spinach that has been overwintered, will benefit from being fed with nitrogen-rich liquid feed once new growth is starting again. This is most likely to happen in March or April.
From October onwards, your spinach might need some form of protection against the cold, depending on where in the UK you live. In milder areas, your spinach might be fine, otherwise cover it with a cloche or horticultural fleece.
In warm and dry weather, mainly in summer, water your spinach plants regularly.
Harvesting Your Spinach Plants
Harvesting can be done in two ways, either by picking individual leaves or harvesting the entire plant.
If picking leaves individually, harvesting small leaves can begin after 4 weeks.
Plants will continue to produce leaves for several months or more if they are harvested regularly. This method is ideal for salads or small continuous harvests.
Harvesting the entire plant was very common in the past. If you are wanting to harvest many leaves for steaming or boiling, this is the best method. The plants are usually ready for harvesting at 8 weeks.
Do not allow the plants to remain in the ground much longer than this as they will begin to take on a bitter taste.
How To Grow Spinach Without It Bolting
Now that you know the basics, let’s talk about growing spinach without bolting.
While bolting, or setting seed, is a natural process that every spinach plant will eventually go through, you don’t want your spinach to do so prematurely.
Because once it starts to grow flowers, it will not produce any new leaves and the ones still on the plant will taste bitter.
This means all you can do is pull it out and throw it on the compost. The good news is, it’s not difficult growing spinach without bolting.
If you follow these three steps, your spinach will be less likely to bolt:
- Provide shade – spinach prefers cool temperatures, so during summer provide shade, maybe sow seeds that will grow during summer in a shady spot.
- Water regularly – spinach is more likely to bolt when the soil is dry, so making sure you water on a regular basis will keep the soil moist.
- Bolt resistant variety – choose a bolt resistant variety, which will be less likely to set seed in warm weather.
Growing spinach in pots can also help, because you can move the pot to a cooler area, when the weather gets warmer. Read our step-by-step guide to find out how to grow spinach in pots.
Grow Perpetual Spinach
Alternatively, you can do what I did and grow perpetual spinach. This is a foolproof way of growing spinach without bolting.
Admittedly, perpetual spinach is not actual spinach, but a member of the chard family. However, it tastes very much like spinach and is just as good for you.
But it has other advantages too:
- Does not bolt – like real spinach, perpetual spinach prefers cooler temperatures, but it can tolerate dry and warm weather and won’t bolt.
- Longer growing season – because it’s a biannual, it will produce crops for almost a year.
- Leaves won’t get bitter – unlike real spinach, the leaves of perpetual spinach will not become bitter if they grow bigger.
- Vigorous growth – perpetual spinach will grow vigorously, which means you will get a fabulous yield.
These are all reasons why, this year, I decided to give it a go.
There are various varieties of perpetual spinach, but I have chosen one called “Leaf Beet“, because it is a summer/winter vegetable. This means it can be harvested from summer and on into winter the following year.
To prepare the vegetable bed, I added a good amount of organic matter, in the form of compost. While perpetual spinach is not very fussy, it will thrive in soil with plenty of nutrients.
However, if you have a shady spot with poor soil, and you are looking for something to grow, perpetual spinach will do.
I have sown the seeds directly into one of our raised beds in mid-April.
Top Tip: Whenever you sow seeds into a bed, make sure you give it a good soak afterwards.
I wanted to make sure that we have enough spinach to eat it every week, so opted for two plants. As I thought that one per person would suffice.
Because perpetual spinach can grow quite vigorously, I left about 20cm (8in) between the plants.
The seedlings germinated after 14 days, which is within the normal range of 12 to 20 days.
How I Cared For My Perpetual Spinach
Because perpetual spinach likes moist soil, I watered the plants regularly.
Especially as we got into summer, and it got warmer.
We had a really dry and hot summer this year, with some days reaching temperatures of almost 40°C (that’s 104°F in old money).
And this heatwave has proven that growing perpetual spinach is the best way of growing spinach without bolting, because our plants did not set seed.
However, we did water the spinach plants a lot during this hot period. Sometimes twice a day, once in the morning and once in the evening. As we did with all our plants.
After 4 weeks, when the plants had started to grow well, I gave them a liquid feed. I used the liquid fertiliser that we get from our wormery.
But this seaweed liquid feed will work just as well. I used it before we started our wormery.
- Seaweed plant fertilizer promotes strong growth, increased crop yields and lush foliage
- Multi-purpose fertiliser which includes extra iron and plant based amino acids that feed garden plants and improve yield
- Suitable for use on lawns, fruit, vegetables, flowers, trees and all garden plants
At the start of summer, I noticed black aphids on my perpetual spinach, which even seemed to be “farmed” by ants.
This is one of the few pests you have to contend with growing spinach and perpetual spinach.
Because part of our garden is a wildlife garden, I decided to wait and see if natural predators, such as ladybirds, will take care of it.
I checked on my spinach plant every day though, to make sure the aphids would not destroy them.
The plants kept on growing very well despite the pesky little creatures. I just had to make sure I rinsed the leaves very well before eating them.
And as summer progressed, I saw fewer aphids. We are now in September and there are no pests on our spinach plants.
This goes to show that you don’t need to buy expensive pesticides to keep your veggies safe from pests.
Just encourage natural predators and let them do their thing.
Harvesting My Perpetual Spinach
I harvest mine with the cut-and-come-again method. This means I just go out and get some leaves from each plant and add them to my meals.
Because perpetual spinach grows quite big leaves, which you can eat, it doesn’t matter if you don’t harvest too regularly.
I had enough for two meals every week so far. And I call that a very good yield.
And I hope to continue to harvest into the beginning of next year too.
Now that you know the secret to growing spinach without bolting, have a go and enjoy your healthy greens. Happy Growing!