When my husband and I first went blackberry picking about six years ago I emailed Canberra Connect asking for information. If you want to go blackberry picking I suggest you find out the current ACT Government policy on blackberries, but this is along the lines of what they said at that time: Because blackberries are considered a weed the ACT Government regularly sprays poison on blackberry canes throughout the ACT. However, they signpost the poisoned areas and never poison during fruiting season.
This is what I've learnt from several years of Canberra blackberry picking: The best blackberries come after lots of Spring and early Summer rain. The biggest and juiciest ones are always deep in the middle of a huge clump of very spiky canes, so wear old clothes and know when to stop going deeper! I find it easier to take several small containers rather than one big container. Once you get home and have eaten your fill of fresh blackberries and made jam, freeze your remaining blackberries and they should keep until you want to make hot crumbles and tarts in winter. To freeze blackberries: wash and drain them, line a tray with baking paper and spread a single layer of blackberries on the tray. Freeze them overnight and the next day pour the frozen berries into a ziplock bag. Freezing them in a single layer means they won't clump together and are much easier to use straight from the freezer.
As for where is a good place to go blackberry picking - you don't think I'm going to give away my top spots do you?!
Frozen berries packed up for the freezer.