On a recent garden tour, someone asked me what I do about black spot on my pawpaws.

“I chop down those trees,” is the answer.

The first year we were here, I propagated and planted fifty or more pawpaws.  They’re easy to propagate, fast to grow, short lived, and I needed nursery trees to pave the way for my (expensive) bought fruit trees.  The seed came from trees that had done well in a drier, more inland climate of a bit further north. But here, about 80% of them suffered from a bad case of black spot.

There are lots of tricks online to treating plants and fruit for black spot, but I’m a lazy gardener. It’s all a lot of work, that makes homegrown pawpaw expensive in time and labour.  Instead, I cut out all the trees worst affected and saved seed from the plants least affected. And I’ve been doing the same each year since.  Over time I’m building up a landrace pawpaw variety that is relatively immune to blackspot and tastes amazing.

ABC Gardening Australia presenter, Jerry Colby-Williams, wrote a great post on social media this morning, about the value in saving your own seed.  “By saving seed from your best plants each year you can improve your crops, creating localised cultivars adapted to local soils and conditions.” He tells a great little story about creating a Chinese celery cultivar suited to his sub-tropical garden within a few years.

“The seed came from a private grower in Tasmania and the plants grew well until their first hot, wet, humid Queensland summer when most developed bacterial leaf-spotting – a very common disease – and to die back. I saved a few seed from the sole surviving plant. By the fifth year of saving seed from my best, most leaf-spotting disease resistant plants (they all carried some disease) I had my very own dependable, subtropical adapted cultivar of Chinese celery.”
 
It’s called “landrace gardening”,  and it is how you create unique varieties suited to your climate.