Oenanthe javanica, productive, low toil, crop

I've found the plant Oenanthe javanica (Water Dropwort, Vietnamese Celery, Water Celery) to be a highly productive perennial crop in my temperate garden, so far, I've found only Vietnamese Mint (Persicaria odorata) to be more productive and tasty.  Leaves grow back quickly after picking and it spreads quickly. It can be continuously harvested over spring, summer and autumn, much less productive in winter. I grow it in tubs as an aquatic, I have also noticed it escape into moderately moist soil nearby in the garden.

It will grow in full sun but growth is more luxuriant and leaves are noticeably softer and better to eat with some shade, 2-3 hours direct sun a day seems to be optimal.

The stems and leaves have a pleasant taste, somewhat like carrot, also seem somewhat metallic or mineral to me, in a good way. I don't think I have encountered the "white floating rhizome" which has been valued highly as food (1). I have encountered what looks to me more like a modified stem, pale green, running along the surface of the soil under the water spreading out roots as it goes, it has the same taste and texture as the stems.

I rarely if ever have to weed the tubs with this plant in it, it tends to monopolize an area, at least when grown in water (in Wellington, New Zealand). Seems like a perfect "low toil" species, requiring little or no care, ideal for "modern" gardeners, generally less accustomed to physical work than their ancestors.

Suitable for a small space such as an apartment balcony.

Government conservationists have very recently become concerned with the vigor of this plant in native water systems in New Zealand (2). I would argue the benefits of this plant outweigh the costs so hope it is never banned from home gardens. Many perfectly good aquatic food plants are already frustratingly banned in the name of supposedly virtuous native purity. Trying to restore pristine native aquatic ecosystems seems futile to me, the "weeds" have won as far as I can see.

  

1. Edible Water Gardens. Growing water plants for food and profit. Nick Romanowski. 2007

2. https://www.stuff.co.nz/environment/123694247/pest-plants-invade-richmond-waterways-go-ballistic-across-new-zealand