In Production Today: Subtropical Spring

Arrowroot/ Comfrey Challenge: which plant is most productive in the subtropics?

The Comfrey/ Arrowroot Challenge: Which is most productive in the subtropics?

Sweet spring: Do you find that when you are picking certain seasonal plants from your garden that life somehow seems sweeter? Right now, my winter sown chervil and watercress have such soft, juicy, delicate, fresh growth in my garden they are a delight to handle.

I grew up with these two crops, there always seemed plenty in my grandparents London garden. Like mint, they escaped from positions dedicated to their cultivation and their seed found its way into all the nooks where they were happy to grow themselves. All we needed to do was pick and enjoy them. Culinary bliss!


Cold damage on tropical plants is often slow to surface. I’ve spent about four days this month trimming and pruning back tender plants that were damaged by a wintry East Coast Low weather system last month.  The Mexican tree spinach (Cnidoscolus aconitifolius) entirely defoliated, and the Pandan (Pandanus amaryllifolius) has yellowed and many leaves are unuseable. Chilli fruit stopped swelling, my numerous ‘Piri Piri’ chillies are tiny, like red dots.

The cool really suited my annual nettles (Urtica urens) which made nettle soup, I’ve got one bag full of Arrowroot (Canna edulis) rhizomes waiting to be cooked. The mild-flavoured Chilli ‘Corno di Toro’ (bull’s horn) made a mouthwatering chilli jam which only lasted a fortnight before it was all eaten.

Pigeon pea (Cajanus cajan) have been late, I’ll pick them later this week after filming with Gardening Australia.

In this garden I grow Queensland arrowroot (Canna edulis) for mulching and compost making because it grows so reliably. So many visitors have asked why I don’t grow Comfrey (Symphytum x uplandicum) for compost-making and mulching. I guess the reason is because Comfrey, a cool climate perennial, has been popularised by northern hemisphere gardeners who cannot grow a decent crop of Canna edulis, a warm climate perennial.

So I cleared a bed where I will trial equal plantings of both. Over the spring to autumn growing season I hope to demonstrate which species – either Comfrey or Queensland Arrowroot – uses the least amount of water to grow successfully, and which produces the greatest amount of organic matter. I dug the bed over, working in well-rotted horse manure into the top soil. After planting, I mulched the surface with layer of Sugar Palm flowers (Arenga pinnata). This palm bloomed in autumn and left a pile of fallen flowers big enough to fill three wheelbarrows. The trial bed is pictured, above.

The Stinking Roger are tall, delicate and flowering their hearts out. Time to make ocopa with huacatay sauce!

Now to finish mulching my spice border with home made compost. Here’s my spring menu:

Edible roots and shoots

Aerial potato, Dioscorea bulbifera;
Arrowroot, Canna edulis;
Cassava, Manihot esculenta;
Cassava, Manihot esculenta ‘Variegata’;
Cocoyam, Xanthosoma saggitifolia;
Sweetpotato, Ipomoea batatas ‘Ace of Spades’ (small, tasty tubers);
Sweetpotato, Ipomoea batatas ‘Marguerite’;
Yam, winged, Dioscorea alata;

Edible leaves

* Basil, lemon, Ocimum x citriodora
* Basil, sacred, Ocimum tenuiflorum;
Cabbage, Ethiopian, Brassica carinata;
Cha-plu, Piper sarmentosum;
Chickweed, Stellaria media;
* Chicory, Cichorium intybus;
Chicory, Cichorium intybus ‘Red Dandelion’;
Chinese celery, aka smallage, Apium graveolens;
Chervil, Anthriscus cerefolium;
Chives, Allium schoenoprasum;
* Coriander, Coriandrum sativum;
Curry bush, Helichrysum italicum;
Curry leaf, Murraya koenigii;
Dandelion, Taraxacum officinale;
* Dill, Anethum graveolens;
* Endive, Cichorium endivia ‘Green Bowl’;
Eschallot, Allium cepa var. aggregatum;
Fennel, Florence, Foeniculum vulgare Azoricum Group ‘Zefa-Fino’;
Garlic chives, Allium tuberosum;
* Green Amaranth, Amaranthus viridis;
* Huauzontle, Chenopodium berlandieri;
Japanese parsley, Cryptotaenia japonica;
Kaffir lime, Citrus hystrix;
* Lagos spinach, Celosia spicata;
Landcress, Barbarea vulgaris;
Lebanese cress, Aethionema coridifolium;
Lemongrass, Cymbopogon citratus;
* Lemongrass, Native, Cymbopogon flexuosus;
* Love-lies-bleeding, Amaranthus caudatus;
Love-lies-bleeding, Amaranthus caudatus ‘Green’;
Lettuce, Lactuca sativa ‘First Fleet’;
Marjoram, Origanum marjorana;
* Mint, Corsican, Mentha requienii;
Mint, native, Mentha satureoides;
Mint, Moroccan, Mentha spicata;
Mizuna, Brassica juncea var. japonica ‘Red’;
Mizuna, Brassica juncea var. japonica ‘Ruby Streaks’;
* Mustard, Brassica juncea ‘Osaka Purple’;
* Mustard, Brassica juncea ‘Giant Red’;
* Nasturtium, Tropaeolum majus;
* Nettle, annual, Urtica urens;
Old man saltbush, Atriplex nummularia;
Onion, Tree or Egyptian Walking, Allium x proliferum;
Onion, Welsh perennial, or perennial spring onion, aka scallion, Allium fistulosum;
Pandan, Pandanus amaryllifolius;
* Parsley, Petroselenium crispum ‘Italian flat-leaved’;
* Purslane, Wild, Portulaca oleracea;
Radicchio, Cichorium intybus;
* Rocket, Wall or wild, Eruca saliva;
Society garlic, Tulbaghia violacea ‘Variegata’;
Society garlic, Tulbaghia violacea ‘Fairy Stars’;
* Stinking Roger, Tagetes minuta;
Sweetpotato, Ipomoea batatas ‘Ace of Spades’;
Sweetpotato, Ipomoea batatas ‘Marguerite’;
Thyme, Variegated, Thymus serpyllum ‘Variegata’;
Variegated four seasons herb, Plectranthus amboinicus ‘Variegatus’;
Variegated four seasons herb, Plectranthus amboinicus ‘Bayside Beauty’;
Vietnamese mint, Persicaria odorata;
Watercress, Nasturtium officinale;

Edible petals

Bedding Begonia, Begonia semperflorens;
Begonia, Begonia ‘Dragon Wings’;
* Cranberry Hibiscus, Hibiscus acetosella (excellent for tea);
Canna, Canna iridiflora;
Goldenrod, Solidago sp.;
* Stinking Roger, Tagetes minuta;

Edible seed

Chilean wine palm, Jubaea chilensis;
Fennel, Florence, Foeniculum vulgare Azoricum Group ‘Zefa-Fino’;
Pigeon pea, Cajanus cajan;

Fruit and pods

Banana (ripe), Musa x sapientum ‘Java Blue’;
Banana (green), Musa x sapientum ‘Ladyfinger’;
Banana (green), Musa x sapientum ‘Goldfinger’;
Bean, climbing, Phaseolus vulgaris ‘Purple King’;
Capsicum, Capsicum annuum ‘Corno di Toro’;
Chilean wine palm, Jubaea chilensis (preserved in pandan-flavoured syrup);
Chilli, Capsicum annuum ‘Hungarian Hot Wax’;
* Chilli, Capsicum annuum ‘Long Red Cayenne’;
* Chilli, Capsicum annuum ‘Piri Piri’;
Kaffir lime, Citrus hystrix;
Lime, Tahitian, Citrus x latifolia;
* Mouse Melon, Melothria scabra;
* Pawpaw, Carica papaya ‘Southern Red’;
Pepino, Solanum muricatum;
Tomato, Lycopersicon esculentum ‘Apollo’;

Medicinal / Spices

Aloe vera – leaf juice used to heal sunburn, scratches, and for shampoo;
Bulbine frutescens – leaf juice used to treat burns, rashes, as an infusion for sore throats;
Brahmi herb, Bacopa monnieri – aids cognitive function;
Cardamom, Eletteria cardamomum;
Cardamom, False, Alpinia nutans;
* Catnip, Nepeta cataria; the juice left by rubbing elbows and ankles with fresh leaves helps deter mosquitoes;
Galangal, Alpinia galangal – spice used like ginger with similar properties;
Ginger, Culinary, Zingiber officinalis – spice that helps decongestion of catarrh, aids digestion, blood flow;
Ginger, Shampoo, Zingiber zerumbet – from Seed Savers. Juice from leaves and roots (rhizomes) used to wash hair;
* Greater celandine, Chelidonium majus – stem juice kills warts on hands;
Krachai (root), Boesenbergia rotunda;
Rosemary, dwarf, Rosmarinus officinalis ‘Benenden Blue’;
Rosemary, fastigiate, Rosmarinus officinalis ‘Miss Jessopp’;
* Skullcap, Blue, Scutellaria lateriflora;
Turmeric, Curcuma longa – spice with anti-cancer, anti-stress properties;

* denotes a volunteer crop

Total 104 taxa

Jerry Coleby-Williams
24th August 2015