At a glance, raspberries and blackberries may seem nearly identical, especially when black raspberries are considered. But they are two distinctly different plants that can be distinguished by several characteristics.
Both blackberries and raspberries are in the brambles category, thorny plants in the Rubus genus. Blackberry plants produce black, roundish fruit and are generally taller, while raspberry plants produce light red or black oblong berries and have more thorns.
If a core, also called the torus or rasp, is left on the vine when the berry is picked, the berry is a raspberry. Blackberry cores will stay inside the berry.
After leaving the core behind on the vine, raspberries will have a hollow center. Blackberries will not have this indentation and thus will be heavier but also more full of seeds.
Raspberries survive much better than blackberries in colder temperatures. Blackberries tend to die off if the thermometer dips below -10 F unless they are insulated by snow.
Raspberries generally ripen in the middle of summer, earlier than blackberries, which follow soon after.