Living on a property in the subtropics where I rely totally on rainwater and natural rainfall for watering, I love growing vegetables and at times have been virtually self sufficient, as well as giving excess to friends. However, I am often in full production over the summer and autumn months when it is hot, wet and humid and this is not the time to grow traditional northern European crops.
I am often busy on weekends and vegetables that don’t require constant maintenance are therefore the backbone of my vegetable garden and I suspect these plants are the ones that many other time-poor gardeners would find most reliable. Interestingly most of them were the staple plants grown in my area decades ago, when gardeners relied on their own produce and grew plants that were suited to the local climate.
Here are my top 10 vegetables to grow in the subtropics:
1. Cherry tomato (Solanum lycopersicum var. cerasiforme)
A few months after moving to my current property, and before I started to do much in the garden, a cherry tomato plant appeared in the rocky subsoil on a barren dam wall. Within a month or so it was covered in fruit – very large and delicious fruit. As much as I picked them, the more tomatoes the plant produced. First they were used in salads, then in sauces and finally in delicious tomato soups. Cherry tomatoes lend a distinctive and delicious flavour to cooked dishes. I love the way they burst in your mouth – little bombs of flavour.
Today this same area where the cherry tomato appeared is mulched and the soil is now a rich brown, due to cultivation and the addition of large quantities of organic matter. Whilst I continue to remove tomato seedlings among the groundcovers at the front of the garden, there is always room for a few tomatoes to grow between the establishing shrubs. These plants have continued to grow and fruit copiously despite the 7 months of drought we have recently endured.
Cherry tomatoes are a very different breed to the prima donna tomatoes with the larger fruit. They are vigorous, and generally disease and pest free. This includes the ubiquitous fruit fly, which dislikes the thicker skins of this tomato. They also come in a wide variety of colours and flavours.
2. Pumpkin (Cucurbita maxima and Curcurbita pepo)
I’m a fan of blue pumpkins such as ‘Queensland Blue’, ‘Triamble’ and ‘Oxheart’. I prefer the flavour and consistency of these pumpkins in savory dishes and soups. However blue pumpkins are less widely available these days as many cooks find the hard skin difficult to slice and the pumpkins too big for the dishes they intend to make. Sadly these big blue pumpkins are disappearing from the grocer’s or supermarket shelves and our gardens and being replaced with the increasingly popular “Jap” pumpkin (more correctly ‘Kent’).
As much as I resent the lack of diversity in pumpkins and the dominance of the “Jap” pumpkin in our lives, I have a newfound respect for this cultivar.
A seedling appeared of its own volition at the edge of a garden bed a couple of years ago. I suspect it came up as the result of incorporating some home made compost. Before I got round to removing the seedling, it was off and away and young pumpkins were visible. By the end of the season the plant had produced over 80 pumpkins. Friends often went home with them. The only maintenance involved was directing the growth of the plant over the lawn rather than over adjacent groundcover plants in the garden bed.
I finally cut the plant back last August, after removing the last fruit. However by October this same plant was back again, and before I had a chance to remove it, the first fruit were almost ready to pick.
I still have half a dozen fruit from last year. They are still in good condition but lack the flavour and sweetness of the fresh fruit. I can see why pumpkins were such a mainstay in the early pioneer gardens. They are hardy, prodigious producers and provide a year round crop which is readily stored. The local wildlife don’t seem to like them either. They will give the odd pumpkin a peck or bite, but this is it.
Whilst the “Jap” may be a super star when it comes to production, all pumpkins grow well in the subtropics. They are generally sown in August or September in beds well dug with large quantities of compost and a good handful of fertiliser. Keep the young seedlings well watered and once they are away, remove all but the most vigorous of plants.
Give these plants plenty of room to spread as they can readily cover 3 to 5 metres of ground. An old trick is to keep turning the runners back into the centre of the plant to limit them spreading too far. If you lack space, try some of the compact cultivars such as ‘Golden Nugget’.
Keep the plants well fed and watered during the growing season and stand back!
3. Poor Man’s bean/lablab bean (Lablab purpureus)
The Poor Man’s been was widely grown in northern Australia last century, particularly in rural areas. This heirloom bean was a reliable ‘stand by’ and is grown on farms in my area to this day.
Poor Man’s Bean enjoys a tall frame or teepee upon which to climb. The beans are broad and fleshy, and produced in large quantities. Pick them young and daily to encourage continued production. Unlike the more common green bean, this plant is a lot more drought, pest and disease tolerant. It will also tolerate slightly saline water or soils.
A short-lived perennial plant, it will continues to produce beans for 2 to 3 years. However the best production is in the first year.
This attractive plant also has edible young leaves and edible sweetpea-like flowers. I have used the leaves in both salads and cooked dishes. The flowers make an attractive garnish.
The beans have a stronger ‘beany’ flavour than the more popular green or French beans we know and love. They are particularly well suited to curries, stir fries and stews, where the flavour and texture can complement and stand up to other strong flavours.
Beware, Lablab beans include many different and distinct cultivars. Some have fleshy, flavoursome, edible, young pods whilst others are used as agricultural fodder crops and are quite inedible. Don’t buy the wrong seeds. Seeds of the Poor Man’s Bean are not readily available commercially, but are often grown by senior gardeners or in rural areas. They are often available at organic gardening clubs or events.
4. Choko (Sechium edule)
I escaped the culinary horrors of mid-century Australian vegetable cookery. However I have tried some of the choko recipes from this era. They are simply appalling. No wonder many people cannot stomach the thought of eating this vegetable. Don’t blame the vegetable – blame the cook! The choko may not be a ‘Diva’ vegetable, but it is certainly a talented member of the supporting cast in any dish. Just like zucchini, squashes or eggplant, it absorbs flavours and provides a crisp texture to a dish.
Whilst native to Mexico, I have had delicious dishes utilising this vegetable in South East Asia, France and Italy, where chefs have recognized its great potential. More recently many of our well-known cooks have used their skills to showcase this wonderful vegetable.
The choko’s vigor and ease of growth is legendary. More infamous still is its productivity. Flower initiation and then fruit production are triggered by declining daylight hours. This leads to a feast or famine scenario. Start picking early. Sweet, young, walnut sized fruit are delicious picked straight from the plant, added to salads or lightly cooked in hor d’oevres. Half grown fruit are much more tender than the fully formed fruit sold in the supermarkets and lack the central seed.
Everything about the choko is edible. The young shoots ,which are a popular green vegetable, and the root of younger plants is also widely eaten.
Plants appreciate organically enriched, moisture retentive soils and a large and solid climbing support. A water tank, shed or outdoor “dunny” make great supports and will soon be completely covered.
While there are many different cultivars of choko, a large green cultivar is most widely grown. I grow the white choko, a cultivar that is seldom seen these days. The fruit are a luminous white and less slimy than the popular green variety. The fruit look stunning on the vine and an added bonus is you can find them at twilight or by torchlight if you need to locate some vegetables late in the evening.
5. Ethiopian or Kenyan Cabbage (Brassica carinata)
Most of the Brassicas we grow (cabbages, cauliflowers, broccoli, kale and Brussels sprouts) originate in the cool, moist climates of northern Europe. Whilst they may grow well in the cooler subtropical winter, they quickly bolt to flower as the temperature rises.
The ancient cabbages from North and Central Africa are a different breed and happily grow through the hottest, wettest and humid summers. They form large open heads of delicious sweet flavourful leaves.
Like any of the leafy Brassicas, these plants appreciate deep well-worked, highly fertile moist soils and regular applications of fertiliser. They quickly grow into large leafy rosettes, which are very attractive in the summer garden.
This is the cabbage that provides an authentic flavour to an African dish. However it is also a great substitute for cabbage or kale over the summer months.
6. Sweet potato (Ipomaea batatas)
Sweet potatoes thrive in our subtropical climate. They soon form a dense leafy groundcover. Plants can be propagated from cuttings or from sprouted tubers. They are best planted out as the weather starts to warm in spring.
Sometimes the issue is how to control growth on these plants. Many gardeners trim them back over the growing season to keep plants compact and use the shoots as a green vegetable or as propagation material for further crops.
Another problem is finding tubers at harvest time. Gardeners often place small sticks or stakes next to the newly planted cuttings to mark the spot.
There are numerous cultivars of sweet potato being grown in Australia, with variously sized, shaped, coloured and flavoured tubers. Currently the popular orange ‘Beauregard’ is most widely available. This intrigues many overseas visitors as these orange cultivars are generally used for sweet rather than savoury dishes overseas. Like potatoes, the varied sweet potato cultivars are often suited to specific dishes.
The main enemy of the sweet potato is the bush turkey. They will destroy a crop overnight. Many people plant their cuttings under pegged chicken wire to protect the juicy tubers. Sweet potato weevil can also be a problem in some areas.
7. Luffa (Luffa cylindrica)
The luffa plant is a vigorous vine well suited to training over a pergola or large trellis. This highly productive plant can look quite ornamental when covered with hanging fruit.
The fruit can be used in a diversity of dishes, as a substitute for zuchini. The fruit is a little moister than a zucchini and has a distinctive but attractive flavour.
Luffa plants are certainly a lot easier to grow than zucchinis and suffer from few, if any, pests or diseases. Being a large vine they are less sensitive to periods of dry weather or heat. However like all vegetables, you will be rewarded for additional watering and feeding by the increased production of these delicious fruit.
If you can’t keep up with all the fruit on the vine, leave them mature and you will produce your own bathroom sponges. Wash of the flesh from a mature fruit and this is what you are left with.
8. Sweet Leaf (Sauropus androgynus)
My favorite vegetable, with the most delicious ‘greens’ you can ever eat, grows on an ornamental shrub. The leaves are true to their name and have a delicious nutty flavour which many people compare to peas. The leaves can be eaten from the bush, added to salads, or lightly cooked in a dish.
The plant naturally grows as an attractive, open, willowy shrub 2 to 3 metres tall by 2 to 2.5 metres wide. However it is generally pruned as a more compact shrub to 600 to 1 metre wide by 1 to 2 metres high.
Plants grow best where they receive morning sun and some protection for harsh afternoon sun. They will also grow well in semi shade or where there is shade for part of the day, which makes them ideal for many urban gardens.
Plants prosper in deep organically enriched soils with regular applications of fertilizer. They appreciate additional watering during dry periods to maintain vigorous growth.
9. Surinam spinach (Talinum triangulare)
You can’t have too much spinach over summer. This plant will surely deliver all the greens you can eat. It is also very ornamental, forming a small bush of fleshy deep green leaves topped with attractive pink flowers….. An ideal plant for an ornamental potager garden.
Being a succulent plant, it will survive through dry periods and then shoot back into vigorous growth as the warmth and moisture returns over summer. It will also grow well in semi-shade or areas shaded for part of the day.
Leaves should be only lightly cooked and added as the last ingredient to the dish. Many people eat both the leaves and flowers raw, however they do contain oxalic acid, so eating large quantities of the raw leaves is not recommended.
10. Basella, Malabar Spinach (Basella alba)
This vigorous climbing plant produces large edible, broad, fleshy leaves. It soon cavers a trellis or frame and one well-grown plant can produce enough spinach to feed a family.
There is secret to using the leaves in dishes. Add them after all the other ingredients and cook briefly to maintain the flavor and leaf structure. You can readily overcook the leaves of this plant and end up with green sludge. However many cultures appreciate this glutinous effect and use the leaves to thicken soup or add varied textures to a dish. I find Basella leaves delicious and quite addictive.
The juice from the red berries can be used as a natural, crimson food colouring.
Two forms of this plant are commonly grown. One has bright green leaves and the other has leaves and stems with a reddish brown cast to them. They both taste the same so it is up to you which one you chose to grow.
Basella enjoys moisture and food. If you want a lot of leaves, work lots of organic matter into the soil and then feed and water it well during the growing season.
So there you have it – my top 10 subtropical vegetables. If you are not familiar with some of these plants I recommend you give them a go. They can provide you with some reliable, low maintenance vegetables and can form the backbone for your vegetable garden. You will always have vegetables at hand.