Plant Profile- Atherton Raspberry

When I first moved from the beach to the hinterland my mind raced with all the possibilities. That little bit of altitude and cooler winters opened up the possibility that a range of temperate fruit that had tempted me in plant catalogues from down south for years might finally be possible. Among those were the brambles, genus Rubus, including blackberries, raspberries and various cultivated forms. I ordered as many types as I could get my hands on to increase my chances of getting a little bit of success. Even on the margins of my original intensive vegetable garden most of them showed pretty unremarkable vigour. Only boysenberries both grew, flowered and fruited well. The first flush of fruit in spring were perfect but the large and soft berries quickly attracted the attention of fruit fly. On top of that the vines were floppy, requiring me to construct supports and to regularly train the vines onto them. Inevitably some escaped the trellis and when the garden was eventually abandoned (as all gardens must be in time) the vines created a horrible mess with painful thorns. At that stage I was happy to add Rubus to the list of plants not worth bothering with.

We did have a couple of native species in the genus that grew locally and started regenerating on their own as the cattle were excluded from the waterways and dam edges. Rubus rosifolius forms a dense mass of thin stems with recurved thorns to about 50 cm tall. It produces a few red fruit that look appealing but taste like dry cardboard. The other, Rubus mollucanus, was less common and preferred shady forested places. It produced long arching canes with slightly less vicious thorns, and whatever fruit it produced seem to be snatched by the birds before I ever saw them ripen. Browsing our local land-care I stumbled upon something new- Rubus probus, the Atherton raspberry. This species grows in the mountains from central to north Queensland. I told myself I was being silly but chucked it in the corner of my new veggie garden and forgot about it. After a couple of years it formed a self-supporting shrub about 1.5 m tall (no trellis required) with fairly modest thorns that scratch a bit but don’t sting. The fruit turned out to be 2-3 cm across provided soil moisture was adequate and they actually tasted like raspberries. Not the lollies of the same name by the way, but definitely pleasant eating. Finally I had found something worth growing.

I transplanted some suckers to the edge of a dam. This species also only forms fairly dense clumps, so no mass of suckers spreading far and wide to worry about. This new clump grew to about 3 m in diameter, fruited once, and then appeared to die off during a prolonged wet spell. I thought it was gone but it has since regrown and expanded and this year produced about 2 kg of fruit every couple of days. Like most raspberries the fruit detach with barely a touch when ripe. Birds seem to take some but leave plenty for us and fruit fly shows no interest at all. The fruiting season from mid-winter to mid spring is nice and long, which is ideal for a home grower and fills a gap in the annual fruiting roster nicely, coming in just as the last citrus are fading and bridging the gap to strawberries and blueberries later in spring. I have since worked out how to extract seed from the fruit. Each seed is held in a tiny pocket of flesh. By soaking the coarsely mashed fruit in water for a day or two, interspersed with periodic mashing and filtering, the majority of the seeds will be freed and sink to the bottom, allowing the pulp to be decanted off. Fresh seed germinated readily and I am now selling spare seedlings at the local markets, while saving a few to plant out in a few extra places (though we already have about as much as we need, but I want to hedge my bets in case the large clump collapses again from being too wet). I also occasionally see self-sown seedlings spread far from the original plant in the vegetable garden, probably spread by rodents.

The genus Rubus is very large, with several hundred species, so perhaps there are a few other gems waiting to be discovered. Beyond that the species are broadly interfertile, so I might experiment with hybridisation in the future. Who knows what possibilities await us?

Juicy Atherton raspberry fruit, with hand for scale

Berries ripen progressively over a long period

A glimpse of my raspberry thicket near the dam, with the morning’s haul of fruit