Red Mustard leaf – Brassica juncea – is a interesting edible. It has a hot spicy mustard flavour bite to it and is great used as an addition to salads or used in cooking to add flavour such as for wrapping parcels to steam or BBQ.
The leaves can get to about 40cm long and 30cm wide and the plant grows to about 1.5m high quite fast so you can get a huge variety of leaf sizes along the stems – which are also edible.
It will grow in just about any soil in any weather but seems to like the slightly colder months as long as it gets lots of direct sun. The colder the weather the better the flavour I think. Warm temps seem to bring out the sulphurous flavours more. They also like plenty of water but also seem to thrive in fairly arid environments too as long as there is water under the soil surface. You can tell when they need watering as the leaves just simply start to sag.
The small yellow flowers also have a nice taste but they drop petals very fast so it’s only viable if you pick and eat them almost immediately. The seeds can be crushed and eaten too as a mustard paste. Again this really only viable for taste if it’s very fresh seed.
They self seed very easily. To collect seed you just wait for them to form the pods and let them start to dry out on the plant. At that stage you can trim them off and drop them in a bag to completely dry and break open or whack the bag and collect the seeds from the bottom.