first published 5th July 2019 | updated 24th July 2023
Here are 6 plants that can withstand heat and high humidity without collapsing into sad little smears of slime, and that you can put in a salad without alienating your salad eaters.
The 7th plant on the list, doesn’t fit the tropical perennial profile but can be found in shaded, moist niches all over the world. It’s very small in stature, but it packs an amazing nutritional punch and can fill a salad bowl all by itself.
This post was first published in July 2019; updated June 2023.
Do you struggle to grow tender salad plants because of heat and/or high humidity? This post is about substitutes for lettuce that will grow in tropical and sub-tropical areas.
Our area of North Queensland is known for its reliable rainfall and beautiful waterfalls – which also means that for half of each year everything is covered with mold and the only things growing in the garden are tough tropical perennials and rampant weeds.
So, through our wet months we eat salads made from tropical and sub-tropical perennial plants that can withstand water-logging and high humidity without succumbing to mildew, being devoured by slugs, or dissolving into slime before your eyes.
Here are 6 I’ve been mixing up to make lunch and dinner salads, and a 7th that can make a nutritious and delicious salad all by itself if you have damp shady corners for it to grow in.
Other common names: Timor Lettuce, Indian Lettuce. Scientific name: Lactuca indica
Indian Lettuce is a relative of lettuce but grows faster and taller and can cope with heat and high humidity.
The older leaves are bitter and make good fodder for goats, cattle, pigs, and chickens — but the young leaves taste (to us anyway) so much like regular lettuce that we can base a salad on it and think we’re eating the real thing.
Here’s a link with some info about the variety we’re using in our salads – Serrated Tree Lettuce. (You have to scroll down the page quite a ways to find it, it’s named “Timor Lettuce,” fourth from the bottom.)
Other names: Katuk, Sweetleaf Bush, Star Gooseberry, Tropical Asparagus. Scientific name: Sauropus androgynus.
This shrubby plant thrives in warm, wet conditions, likes a bit of shade, and can (should) be pruned into a thick, edible hedge. If you fail to eat it’s tips often enough, it will grow straggly and messy, so put it near a path where you’ll see it every day.
The more it’s pruned, the more delicious, crunchy, tender green tips it produces, and these are what we put in our salads throughout the warm growing season. (They also make a great crunchy green in a quick saute or stir fry, which I described in “One Garden Meal Per Day.”)
Some references suggest going easy on the consumption of raw sweet leaf; I play it safe by making sure that our salads are well coated with an oil and vinegar dressing (see the note on this near the end of this article) before we eat, and by putting only the most tender young tips into salads. I cook the older leaves.
Other names: Goa Bean, Asparagus pea. Scientific name: (Psophocarpus tetragonolobus.
Winged bean is a perennial tropical climber which produces pods with four “wings” along their length.
The small young pods, chopped, provide an interesting star-like shape in the salad, and add crunch and body. The flowers make a delicate, sweet decoration on top (unless you or your children eat them before they make it back to the house).
If you miss the pods when they’re small and they get to medium sized, they can be cooked as a vegetable. Don’t bother trying to eat the large older pods (unless you’re starving). Goats and cattle will eat the older pods willingly, or you can save them, dry them, and then use the seeds inside as you would use any other dried bean.
More information and an image that includes the flower can be found all the way at the bottom of this page.
Choko tips & sweet potato tips
Choko (Sechium edule); Sweet potato (Ipomoea batatas)
The choko vine’s contribution to the salad bowl are its tender tips, curly tendrils, flowers, and also the smallest fruit, from almond sized to a bit bigger, sliced. I’ve learned not to underestimate the humble choko vine.
I also use the tips of sweet potato vines in salads.
I don’t think you’ll win any cuisine awards by serving a salad made from the tips and smallest new leaves of the sweet potato vine. But if you put just a few of them in no-one will notice, and you’ll be raising the nutrition profile of your salad as well as making better use of an-always-ready plant that’s just begging to be better used. If you like you can soften the sweet potato tips by sitting them in the salad dressing for a bit before adding the rest of the greens and serving.
Choko’s can be a bit tricky to get going, but once they’re established they are zero-maintenance and very abundant. I use excess runaway vines to feed to the pigs, and the spent vines at the end of each growing season to mulch the ground around the vine. Image by author.
Sweet potato – an attractive, zero-maintenance ground cover. Every part of the plant is edible, though the tough older leaves are not very palatable to people. All of our animals will eat them, though: chickens, pigs, cattle, goats and horses are all happy to handle excesses sweet potato runners.
Other names: Stonecress, (Aethionema cordifolium)
Lebanese cress is a low-growing perennial with fern-like leaves which forms an attractive ground cover. It likes to be moist and will grow very happily at the edge of water. It will cover a large area so long as there is adequate moisture and a bit of shade.
In a salad, Lebanese cress is on the chewy side, so use just the tips and if you like you can let it sit in the salad dressing to soften a bit before adding the rest of the salad, tossing, and serving.
Lebanese cress is a great salad ingredient, with a faint carroty flavour.
Other names: Water Spinach (Ipomoea aquatica)
A ground-covering, water loving Thai vegetable that likes moist soil and can also thrive in standing water. It’s related to sweet potato and looks similar when it covers an area. Its tips are more tender than sweet potato tips. Young leaves, stems and tips are said to be good cooked in a stir-fry or steamed, but my favourite (easiest) use of it is to put the youngest leaves and the tips into a salad bowl.
Kang kong, looking a bit straggly during the cooler weather.
The first part of Chickweed’s botanical name—Stellaria—means “stars,” and to me that’s just what the tiny white flowers of chickweed look like – little stars scattered in a green sea of salad just waiting to be transferred to my harvest basket.
This special, delicate, low-growing plant is a bit different to the others in this article, in that it doesn’t fit the tough/hot/tropics profile. Chickweed grows all over the world where-ever there are cool/shaded, moist, fertile conditions (thats right: lawns are ideal chickweed habitat). This article talks about harvesting chickweed in an English winter (it also shares good information on chickweed’s nutritional profile and medicinal uses) and here I am harvesting it throughout cooler months in Far North Queensland.
You won’t find a more generous, abundant, delicious ground covering salad plant. It’s also a LOT more nutritious than lettuce i .
I very often go out to the garden late in the day to collect a basket of chickweed, nothing else, for a salad that is very nourishing and that everyone in our family, children included, enjoys.
Chickweed creeps into cool, moist little niches and makes a wonderful ground cover. Here, it’s volunteering among the strawberries. Snipping off these leafy tips for your salad bowl will encourage it to grow back thicker and with larger leaves. It self-seeds with wild abandon and the lawn industry spends a fortune on trying to control it.
Get more nutrition from your salad greens
A note on predigesting your salad greens
Susun Weed suggests that we consider eating some of our meat raw and all of our vegetables cooked. She explains that plant cells have a tough wall around them (as opposed to the thin membrane around animal cells) that needs to be “cooked” or processed in some way using heat, freezing, dehydrating, fermenting, or dressing in oil and vinegar – any of which will break down the cell wall and allow us to access and digest the nutrients therein.
Ruminants—the planet’s most successful herbivores—“cook” green plants by fermenting them in the rumen (or “foregut,” an “extra stomach”) before trying to chew and digest them (“chewing the cud”).
Lacking a rumen and not wishing to cook our salads, we can pre-digest them with an application of oil and vinegar in a salad dressing to make raw greens more digestible and their nutrients more available.
Don’t be afraid to dress your salad a little while before you’re going to eat it – it will look less crisp but be more digestible and you’ll increase the availability of its nutrients.
I often put the tougher greens (sweet potato tips and Lebanese cress, for example) in the salad bowl with dressing first and let them sit for a bit before adding the more delicate things, tossing, and serving.
Even an overnight dunking is ok. We often save a dressed salad in the fridge and eat it the next day, soggy but nourishing.
Salad dressing recipe
Here’s the homemade salad dressing we use:
• Olive oil
• Naturally fermented soy sauce
• Apple Cider Vinegar (homemade herbal vinegars are good because they’ll add a healthy dose of minerals in addition to the minerals that the vinegar mobilizes from the greens in your salad… who needs mineral supplements?)
• Optional – finely grated garlic, and/or ginger, and/or turmeric, and/or other herbs of your choice
Fill a jar about half full with olive oil. Add small quantities of the other ingredients.
Shake, taste, adjust.
Douse your salad greens and enjoy.
i. A study found that chickweed topped the charts in a comparison with a number of other wild greens and kale. In fact, kale was at the bottom; chickweed at the top, and other wild greens ranged in between – scroll down for Tables 7 and 8, here.