Tag Archives: Backhousia citriodora

Plant Collector: Backhousia citriodora or the lemon myrtle

The graveyard specimen is in completely open conditions and looks happier for that, despite it originating from rain forest areas of Australia

A friend posted a photo of Backhousia citriodora on Facebook, asking if anybody knew what it was. I was promptly reminded of my plant and rushed out to pick some of the leaves to flavour the batch of kombucha I was just preparing. For it has one of the strongest lemon scents of any plant I know – eclipsing even grated lemon peel  – and is edible.

It is an Australian tree, the lemon myrtle. Its natural habitat is tropical rainforests of central and southern coastal Queensland but it is also an important commercial crop, grown for its very essence of lemon. Fortunately for us, it is not so tropical that it needs to be grown in frost-free conditions though it is presumably happier in milder areas of this country. Apparently it can reach 20m in height though that may be it stretching itself to reach the light in forest locations. In a more open position, ours is hovering around 3 metres but I do cut it back from time to time to keep it more compact. It does not seem to mind being trimmed.

There are more distinctive trees, if I am honest. We used to grow both B. citriodora and its relative B. anisatum (now Syzygium anisatum) and the less popular aniseed flavoured myrtle had the more attractive foliage. But at this time of the year, the lemon myrtle is in full flower and I came across this specimen in the Te Henui cemetery yesterday. It was alive with bees and a wondrous sight and sound. The fluffy clusters of flowers and stamens have their own charm, in a gentle sort of way.

Covered in flowers and alive with bees at this time of the year

I have used the lemon scented leaves to flavour milk-based dishes that lemons would curdle and added it to my fresh harvest of green tea. The kombucha won’t be ready for another five days so I can’t comment yet on how strongly lemon flavoured it is but I see no reason why it will not be effective. I have not tried drying the leaves but the ever-handy internet tells me they retain their lemon aroma when dried. Indeed, Wikipedia gave the following helpful advice: “The dried leaf has free radical scavenging ability”. So now you know.

It appears that lemon myrtle is particularly vulnerable to the dreaded myrtle rust in Australia which has implications for commercial growers and for the plant in its natural habitat. It remains to be seen whether rust-resistant varieties appear but I have not heard reports of it being spotted in NZ yet. Mind you, it is not a common tree here but it is worth growing one in the edible garden alongside the more common but dull bay trees – Laurus nobilis. Unlike the bay, which gets thrips, I have never seen anything much attack the backhousia and I find I need lemon flavouring way more often than I cook with bay leaves.

Flowering this week: Backhousia citriodora

The lemon fragrance from Backhousia citrodora has to be experienced to be believed

I would be the first to admit that the creamy fluffy floral clusters of this small(ish) tree are not showstoppers though they are pretty enough in their own way and make a change for autumn flowering. Nor are the long narrow leaves eye-catching though the red-brown velvety new growth is very tactile. In fact, the visuals of this plant are remarkably modest especially when you consider it is an Australian from the coastal rainforests of Queensland and northern New South Wales. The knock-you-dead aspect is the lemon fragrance when you crush or even brush past a leaf and the flowers also exude wafts of lemon. It has quite the most delicious lemon scent of any plant I know, bar none. This is apparently because Backhousia citriodora, commonly referred to as the lemon myrtle, has higher concentration of citral (lemon oils) than many other plants, including lemon verbena. In fact it is harvested commercially for lemon flavouring. I have to admit that I have not tried it in a culinary context but I will do so. You can apparently use the leaf whole (like a bay leaf) or chopped and it will give a lemon flavour without the problems of curdling, even in milk puddings. So I have read.

While not overly hardy, if given some protection when young, the backhousia should be able to grow throughout most of our area. I have seen it in a protected valley in Canberra Botanic Gardens where apparently it can survive frosts of 8 degrees. It is a member of the myrtle family and it can be clipped. This may be a plant to put alongside a bay tree in the vegetable garden or plant it by a path so you can pluck a leaf to sniff when you pass.