Vegetable

Winter Leafy Vegetables: How to Grow – Vegetable of the Month

Winter Leafy Vegetables stats/requirements at a glance

Ease of Raising: 1/5 – Daily Check-ups
Water: 3-4/5 – Every 2nd day to daily
Sun: 3/5 – Full sun, dappled shade
Training: 2/5 – Minimal; dead, diseased & damaged
Fertilise/Feeding: 4/5 – Fortnightly
Time to Harvest: 1-2/5 – Immediate (purchase) to Soon (from seed)
Frost Hardiness: 3/4 – Moderately tender (can’t cope with severe frost)
Uses Culinary
Most Problematic Nemesis: Dry, hot conditions & Aphids
Container Plant: Yes

 

Lettuce & Spinach Botanical Print    Plaque 1: Botanical Lettuces Horticulture; Jardin potager et jardin fruitier 1870, Vintage Printable  Plaque 2:  Spinach, Flora von Deutschland Österreich und der Schweiz 1885, Kurt Stuber Online Library  Plaque 3: Botanical Lettuces Horticulture; Jardin potager et jardin fruitier 1870 Vintage Printable
Lettuce & Spinach Botanical Print                                                Plaque 1: Botanical Lettuces Horticulture; Jardin potager et jardin fruitier 1870, Vintage Printable
Plaque 2:  Spinach, Flora von Deutschland Österreich und der Schweiz 1885, Kurt Stuber Online Library
Plaque 3: Botanical Lettuces Horticulture; Jardin potager et jardin fruitier 1870 Vintage Printable

 

Quick intro

Given the success I had with the winter leafy vegetables (spinach, pak choi and lettuce); I decided it needed a posting. Leafy vegetables are hard to grow during the hot and dry South African summer, since they bolt (go to seed before producing crop) – the exception being chard. This at least puts some use to the bare vegetable plots in winter. I am going to discuss the cut-and-come again varieties and not the head forming varieties.

 

Winter Leafy Veg plot spinach pak choy lettuce loose leaf


History

The ancient Egyptians knew about lettuce (4500BC) and cultivated it for its leaves and seed oil. Later it was cultivated by the Romans and Greeks. Lettuce was introduced to Britain by the Greeks. In Europe many new lettuce cultivars were developed during the 1800s.

Pak Choi’s origin lies within China and has been cultivated there since the fifth century AD. It isn’t as widely cultivated in the Western countries as it is in Southern China and South-East Asia.

Spinach is quite the ancient traveller. Originating in Iran (ancient Persia) it was brought to China (600AD) via India, it spread to Spain in the 1100s, then to Japan and Korea in the 1400s-1700s and finally made its way to Europe in the 1800s.

 

Science Stuff

Lettuce, Lactuca sativa, belongs to the Asteraceae family, which includes daisies. Lettuce is classified into two categories; cabbage and cos. Cabbage lettuces have rounded heads with soft/crispy leaves, whereas Cos lettuces have elongated, upright heads. Sometimes a third category is suggested for loose lettuces (leaf lettuces) that don’t readily form heads and are the cut-and-come-again/perpetual varieties.

Slammer green oak Lactuca sativa
Slammer green oak, Lactuca sativa

Pak Choi, Brassica rapa (Chinensis group: Brassica chinensis), is a member of the Brassicaceae (Cabbage & Crucifer family) and more related to the turnips than cabbages. Now the Asian greens have similar common names and this can be very confusing. Some of the other names for Pak Choi include; Bok Choi, Chinese chard, Chinese mustard, celery mustard, spoon mustard and Choy Sum. The main classifying feature of the Chinensis group is the fact that is does not make a head.

 

Pak Choy, Brassica rapa, Chinensis Group
Pak Choy, Brassica rapa, Chinensis Group

Spinach, Spinacea oleraceae, is classified within the Amaranthaceae family (formerly the Chenopodiaceae; Beet & Goosefoot family). 

 

Baby Dash Spinach Spinacia oleracea
Baby Dash Spinach, Spinacia oleracea

 

Growing Winter Leafy Veg

All the leafy vegetables listed here require the same conditions to grow. I had them in the full sun (maybe I should put the pak choi in the partial shade next winter…). Anyways, you can also try growing them in full shade in summer, but I have given up on growing them in summer as they are weak, stringy things that bolt.

Sow the seeds once the heat of summer has passed, preferably temperatures below 20oC (68oF). You can stagger your crop by planting at three week intervals, but I don’t think the SA winter is long enough for that – we only sowed once. Five of the Pak Choi (it is verrryy prolific!) and 8 of each of the others should be more than sufficient for the average family (of three-four people). The leafies can be sown directly into the garden or as start-up punnets and transplanted once the first ‘true leaves’ appear.

 

Loose leaf lettuce mixed Lactuca sativa seedlings
Loose leaf lettuce mixed, Lactuca sativa

Keep them well watered, else you’ll have bitter leaves – or worse, bolting leafies! I fed them every two weeks with Starke Ayres Nutrifeed as a half-strength liquid feed.

 

They are generally are trouble-free as few pests are active during this time of year. I did notice however, with some warming temperature, that the aphids get to them. If these are a real problem, just zap them with my anti-aphid organic home remedy.

 

Other Winter Leafy Vegetable Tips

  •  Mulching will help with water retention.
  • Thin out too densely planted leafies to prevent fungal disease.
  • Even though I had sown these in winter, the pak choi still went to seed when the day temperature goes above 15oC (59oF).

 

Pak Choi Bolting
Brassica rapa
Chinensis Group



Leafies can be grown in all the weird tiny spots of the garden or as a catch/fill-in crop between slow-growing vegetables (where they also mark out where the slower-growing vegetable has been planted).

 

Harvesting and Storing

The general rule is that you can harvest up to half of the plant at a given time. Harvesting regularly also stimulates the plants to produce more. Leafies are best harvested in the morning when they haven’t wilted yet and leaves cut with a knife or scissors.

You can’t really store the leafies on their own. All leafies can be left in a cup of water for 5-7 days. I also noticed that leaving them in the water for a day after harvesting takes away any bitterness. The Spinach and Pak Choi can be frozen, but then to go sloppy – so instead freeze them away as part of a ‘meal’. Such as, soups or stews, then it won’t matter too much if they are sloppy.

 

Winter Leafy Veg Harvest Pak Choy loose leaf lettuce baby dash spinach
Winter Leafy Veg Harvest


Propagation

All leafies will go to seed when the weather warms up and the days become longer. If you can spare the space, let them set their seeds for easy collection.

Lettuces are self-fertile & self-pollinating meaning they do not need a pollinating partner. Seeds are harvested when dry and store in labelled glass jars. Seeds are viable for a whopping 6 years! The seeds are dormant after collection and can be used for next season’s plantings. Seeds need to be at 10-15oC (50-59oF) to germinate, higher temperatures (25oC+; 77oF) induces dormancy.

 

Pak Choi flowers are pollinated by insects (the bees appreciate the late-winter flowers when others are scarce). They need to be exposed to cold period in order to flower. Pak Choi may cross with other Brassica rapa spp., such as mustards and turnips – so hand pollinate and cover individual flowers for seed. Seeds mature from the bottom of the inflorescence upwards and the bottoms ones may burst before the top ones are ripe. Pick ripe pods (brown) and leave in a warm, dry place to cure. Pods burst open once ripe and seeds are separated from dried pods with a sieve. Seeds are held in 50oC (122oF) water for 20 minutes prior to sowing.

 

Pak Choi Flowers and Seed Pods
Brassica rapa 
Chinensis Group

 

Spinach plants bare either male or female flowers. Males are borne on long and spindly stalk, whereas females are tight forming clumps at the base of the leaves. Females are wind pollinated. Seeds reach maturity once the plant leaves begin to yellow. Once plants are dry, strip the long stalks of seeds by pulling it through your hands from the base. Prior to sowing, hold spinach seeds at 50oC (122oF) water for 25 minutes to control seed borne disease.

Spinacia oleraceae Afbeeldingen der artseny-gewassen met derzelver Nederduitsche en Latynsche beschryvingen 1800 Kurt Stuber online library
Spinach Male & Female Flowers        Spinacia oleraceae, Afbeeldingen der artseny-gewassen met derzelver Nederduitsche en Latynsche beschryvingen, 1800, Kurt Stuber online library

 

My Winter Leafy Vegetables

I have a mixed seed pack of Starke Ayres loose-leaf lettuces:

  • ‘Dorado’: Red loose leaf cos lettuce
  • ‘Wahoo’: Green tango/curly loose leaf lettuce
  • ‘Slammer’: Green oak loose leaf lettuce

The other two are also Starke Ayres seeds:

  • Spinach: Baby Dash
  • Pak Choy

 

Do you grow specific vegetables in the winter? Or are you able to grow cool-season vegies year-round?

3 thoughts on “Winter Leafy Vegetables: How to Grow – Vegetable of the Month

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