Spinacia oleracea
My favourite nickname for spinach is the Prince of Vegetables, from Persia (now Iran), whence it originated two thousand years ago. The dark green leaves are synonymous with good health and can be eaten either raw or cooked. Plants grow slowly through winter in temperate regions, when the leaves become sweet.
- Spinach is in the same subfamily, Chenopodioideae, as beetroot and chard, and, like them, is biennial. It is commonly grown for a few months only, but longer is possible!
Leaf water content is 91%, compared to 95% in lettuce – for green leaves, the 9% dry matter is high and helps them to survive freezing. Spinach has 4% carbohydrate and 3% protein, and is famous for its iron content. However, it also contains enough oxalates to reduce the body’s ability to absorb iron.
All good reasons to be wary of nutrition charts that list percentages, as though they are all readily available. Microbes are never listed, yet they play a part in how minerals are absorbed in the gut.
- Homegrown spinach gives us these microbes as well as all the other percentages you read about.
Harvest period
- Days from seed to first harvest: 45
- Harvest period depends massively on the sowing date – it is only four weeks from sowing in mid-spring.
- Best climate is almost any except tropical, where I would grow Malabar spinach – see ‘Other types of spinach’ below.
Why grow them
Spinach plants can be productive, and for a longer period than is often realised. Spinach has an unfair reputation for going to flower, but that is the fault of gardeners not of the spinach plant. Too often they sow in the spring, just before its flowering season. Seed packet advice is often not clear about this.
- Best time to sow is late summer, and from that one sowing you can enjoy up to eight months of picking leaves.
- During cold weather, the leaves turn noticeably sweeter. By early spring, in particular, some leaves can be sugary.
Spinach is an efficient plant to have in your garden for repeat picking, and is excellent to eat both raw and cooked. I love it raw, as part of a mixed salad.
Pattern of growth
Spinach leaves are soft and plants look tender; however, they are hardy and tolerate winter weather well, including gales and heavy rain. The worst damage I have ever seen in winter was from hail.
- The natural period of growth starts with germination during late summer. Plants establish through autumn, to survive winter with strong roots and usually not many leaves.
- Spinach is hardy to cold and stands temperatures as low as -15 °C/5 °F for sure, probably lower and depending on wind, plus any snow cover helps insulate plants and their roots.
- Regrowth resumes in spring and until flowering initiates in late spring. Stems appear in early summer, with clusters of seeds.
Flowers are barely visible, pale yellow, and the resulting seed clusters need time to dry on the stems for up to a month.
Suitable for containers/shade?
Spinach grows well in shade, just make sure there aren’t any slugs lurking nearby.
It is also well suited to growing in containers, especially when you are growing it for salad leaves. Plants then never grow too large, because of regular picking, not cutting.
Space as close as 10 cm/4 in. Even in a container, this allows enough root run for plants to crop for several months, especially from a sowing in late summer.
Other types of spinach
The word spinach is used for many plants growing leaves that can be cooked to eat. Here are some examples:
Malabar or Ceylon spinach, Basella alba, is my favourite of these, but needs heat to grow – ideally days above 30 °C/86 °F. I had some harvests in a polytunnel.
- Sow in early summer and give support; pick the leaves through summer and serve them like spinach.
- The flavour and texture are similar to normal spinach, and an option is raw leaves chopped into salads, for a citrus bite.
New Zealand spinach (Tetragonia tetragonioides) can grow new leaves in midsummer when true spinach is flowering. This plant is in the fig-marigold family, a clue to the flavour of its leaves, which is unusual for a vegetable and certainly not like spinach.
Good King Henry (Blitum bonus-henricus) has the nickname Lincolnshire spinach; I am unsure why. Its triangular leaves are slightly succulent, but in taste and texture feel to me like eating paper! Then the plant flowers readily and can become a weed, growing everywhere unless you keep removing the flower stems.
Orache (Atriplex) and saltbush (Atriplex patula) are in the large Amaranthaceae family, which includes weeds such as fathen (Chenopodium album) – this is edible too. You can cook orache or eat leaves raw – the texture is dry and the flavour is alright, but not excellent. Its chief attribute is its deep colour, especially on the undersides of leaves.
Tree spinach grows gorgeous shoots, with a pink colouring that rubs onto your skin when picking. We use them to colour salads but not for their flavour, which is similar to orache. From sowing in early spring, plants can reach 1.8 m/6 ft high. Best remove them in early autumn, or they drop seeds widely.
Varieties
Medania is, in my experience, the all-rounder you need for harvests both early and late. The leaves are tender and quite dark, though sometimes also lighter, and with good flavour.
F1 hybrids come and go in terms of availability. Two that have stood the test of time are Missouri and Emilia. I value them mostly for spring harvests, from sowing very early when their vigour can make a difference, in comparison to Medania.
Giant Winter is best sown in late summer and grows pointed and pale green leaves, but with no extra hardiness that I have noticed.
Sometimes listed with spinach in seed catalogues is beet or perpetual spinach – this is one to avoid if you want true spinach because it is a chard – see Lesson 11, Course 3A. This lesson is all about true spinach.
Clear
This is quick and simple – with your hand around each plant, rotate the main stem until it breaks off at soil level. This leaves most roots in the ground and you are then ready either to plant again, or to spread compost before planting again.
Follow with
Spinach finishes by early summer. Spring sowings are almost a ‘catch crop’, allowing the main dish to follow.
There is time to transplant almost any vegetable as a second planting, from kale and cabbage to leeks and beetroot. Beetroot is the same family as spinach but I have not found any problem with that.