Plant Profile- Eggplant

Eggplant is something of an acquired taste for those who have learnt to love it. The fruit itself is very low in nutritional content and often contains bitter alkaloids that most people have an aversion toward. At its best eggplant is a mellow backup singer that harmonises with and supports the lead (normally bacon in our house). To really shine eggplants need to be young and immature, picked before their seeds develop and turn bitter. We use eggplant in stir fries through the summer and to bulk up stews in the autumn. They need a minimum night temperature to set fruit, so typically production stops around May depending on the weather. With our rare and light frosts we can easily keep the bushes growing through the winter, meaning they are ready to start producing again as soon as the weather warms up and sufficient moisture is available. A good variety should persist and produce well for several years in the subtropics. This is a superior approach to trying to start new plants in our dry springs since the seedlings struggle to build up a frame, meaning those sowed in late summer often fruit around the same time anyway.

There is a reasonable amount of genetic diversity in the species most people call eggplant (Solanum melongena). Like most modern vegetables there are a number of distinct species in the genus that are used in similar ways around the world. This excellent website summarises the group for those who are curious (http://www.plantnames.unimelb.edu.au/new/Sorting/CATALOGUE/EGGPLANTS-intro.html). Among these are the pea fruited species from south East Asia that grow into large, long lived shrubs. The smaller fruit require more work to pick and prepare, but the plant requires less work to grow (a trade-off that we see in pretty much all plants). From this group of species one came to dominate and be gradually bred and selected to suit human needs, in the process having its sharp spines and bitter chemicals that protected it from pests and diseases stripped away. This process reached its extreme as this tropical vegetable was gradually bred to grow during the brief summers in Europe, leading to well-known commercial varieties like black beauty. This variety was also bred to produce massive fruit that are economical to harvest, and with a thick skin that makes transportation easier. By contrast the best Asian varieties produce fruit with thin skin that can be left on during cooking but resulting in fruit that can be tied in a knot after a day in the fridge. After failing with black beauty I achieved reasonable success with Lebanese bunching. This convinced me to do a more thorough variety trial of about a dozen diverse types, leading to discovering Ping Tung. This East Asian variety produces strong bushes that sail through drought and last several years. The fruit are 4-9 inches long but quite thin in a pleasant medium purple. The flavour is incredibly mild compared to other varieties. Thinking about back yard growers struggling to grow cold and commerce adapted black beauty in the subtropics when wonders like Ping Tung exist makes me so melancholy.

One quirk of eggplant is that it is one of the few crops that I routinely start in pots. For one thing if you are buying seed then you will usually get tiny packets of seed of dubious vigour. Don’t waste your precious space and time in the garden waiting for dead seeds to emerge. Sowing in a pot first means you only waste the time and space there if nothing grows, plus you can start them much earlier in late spring or early summer if you want. The other issue is that eggplant seedlings are very delicate when they first emerge and can be wiped out overnight by herbivores like snails. After a week or two they thicken up and can defend themselves. Now I have a larger quantity of my own seed I have found that direct sowing can work, though I tried putting a circle of biochar around each position (though a few I left without any worked as well). At any rate eggplant love charcoal and a periodic dusting of ash as they grow, especially as they are waking up from cold weather to fruit again. I typically sow bought seed in group pots, then transplant small seedlings to individual tubes. This reduces root disturbance during transplantation into the bed. I now also sow my own seed direct into tubes (3-4 seed each) then thin to the strongest plant shortly after germination. This allows me to fill in gaps in my beds from direct sowing, and even rescue the year’s crop if I happen to have snails wipe out all the direct sowed seed.

Seed saving is a little different to other crops as well. They are mostly self-pollinating but if you have native bees active might outcross. The fruit needs to hang on the bush for a long time to mature. Most varieties turn yellow when ready, though you can see hard seeds inside when you cut it open. I leave my last crops of autumn on the bush into winter for many weeks until I am ready to process the seed. The fruit can be simply cut open and the seed scraped out of the flesh with a spoon, though they tend to fly everywhere. I find the best method is to peel the fruit, cut into strips lengthwise then soak in water. The fruit will soften, allowing the seed to be easily extracted by smushing the pulp, allowing the seed to sink to the bottom and the pulp to be scooped off and decanted away. The danger is that seed will begin germinating when floating in the water, unlike tomato that goes through a similar process. If you see tiny root tips emerging then the seed is no good for dry storage. Processing in the cooler weather of winter gives a longer window to get the timing right. In summer seed can germinate in a few hours of soaking, while in winter 24 hours is normally safe (though shallow containers are better to keep oxygen levels high and discourage rotting).

Now that the rains have returned we are picking eggplant, snake bean, shallots or garlic chives and rosemary every day for our stir fry dinner. I weighed the harvest today and it came in at about 700 g, enough for two people to feel like they are getting enough veggies. This daily harvest doubles through mid-autumn to mid-winter, then gradually declines through to the end of the year depending on how dry spring is. If we assume today was an average that means the garden produces about 250 kg of vegetables a year, at roughly $5 per kilogram (ignoring the improved quality versus store bought, but also ignoring the extra time to grow and harvest every day) that means the garden produces about $1250 worth of value, a pretty poor return on the space and time in most people’s eyes. It is worth remembering that this garden gets no imported fertility, turn our goat manure waste into a resource, and never gets watered at all. The soil is still mostly unimproved clay that most people would assume could not produce anything. It is also very difficult to compare good home grown to store bought produce however. My partner and I both remark on how empty vegetable dishes taste when we get desperate during the end of a drought and buy vegetables. And simple analysis of the time spent in the garden is also flawed. All the convenience of the industrial world and all the time and labour it saved just resulted in people sitting around watching television and sitting in traffic jams. Perhaps in leaving behind industrialised society we also have to leave behind its tendency to try to measure and evaluate everything. I now have a relationship with this particular strain of eggplant that will hopefully continue throughout my life and be shared into the lives of others.

The daily vegetable harvest headed to the frypan for dinner with eggs and brown rice, topped with soy sauce.

An old bush sowed three seasons ago in 2018, flushing with fruit once again after a light prune

A longer row of plants mostly direct sowed in 2019. I wonder if they will keep producing as this bed cycles into green manure?