Kitchen Garden: subtropical winter
Arno is a garden designer and writer whose garden in Brisbane is mostly edible.
He is constantly testing the received garden wisdom for its relevance to subtropical gardeners, and trialing new products. Let's see what Arno's growing this winter
The sweet, nutty, crunchy shoots of asparagus, picked minutes before steaming, grilling or frying, are quite unlike anything you could ever buy. Now is the time to plant seedlings, seed or plants of this hardy, long-lived vegetable. A designated asparagus patch is best located at the edge of the vegetable garden where the asparagus roots won't compete with other vegetables and foliage won't overshadow them. Asparagus tends to be evergreen in the subtopics, so a late-winter pruning is required to stimulate production of fat juicy shoots. Stagger the pruning to get a longer harvest season.
To produce the tender, mild-flavoured white asparagus shoots popular in Europe, mound up compost over your asparagus patch to exclude light.
Tomatoes, particularly cherry and currant tomatoes, can be grown year-round in the subtropics. Rotate tomatoes each season and incorporate plenty of compost and balanced organic fertiliser (containing ground rock minerals) into the soil a couple of weeks prior to planting. Tomatoes are the divas of the vegetable world so keep them regularly watered and fed.
Larger tomatoes grown during winter are less subject to pests and diseases. The Russian and cold-hardy European tomatoes do best planted early in winter, while the large American tomatoes grow well and avoid disease and fruit fly damage when planted in late July and removed by November.
Coriander is simple to grow in the subtropics and now is one of the easiest times of year to grow this plant. While it may confound many gardeners, the secret is to grow it from seed in situ, and avoid transplanting plants or seedlings as they will quickly bolt.
Coriander requires an organically enriched soil and regular watering and feeding. Source seed from Asian or on-line organic seed suppliers and look for low-bolt varieties. Sow a few seeds every couple of weeks for an ongoing supply. Remember to let some plants go to seed so you can save some seed to sow. The roots and stems of pulled plants can be used in Thai read and green curry pastes.
Potatoes are traditionally grown during the ‘A months’ (April to August) in the subtropics. Once they are established increase production by gradually hilling up around the plants’ stems with well-composted organic matter. Finding that the root crop harvest of potatoes, Jerusalem artichokes, Chinese artichokes (Stachys affinis) and yacon (sometimes called Peruvian ground apple, Smallanthus sonchifolius) has been decimated by bush turkeys, bandicoots, rats or mice is miserable. So to prevent disappointment, I now grow susceptible root crops under fine chicken wire. Place wire over tubers following planting, extending the wire beyond the crop. Cover with a mulch, 75 to 100mm deep.