Yes. In your console (F5) type "spawn" followed by any of the following:

Pickable_Barley

Pickable_Barley_Wild

Pickable_Carrot

Pickable_Dandelion

Pickable_Flax

Pickable_Flax_Wild

Pickable_Mushroom

Pickable_Mushroom_blue

Pickable_Mushroom_yellow

Pickable_SeedCarrot

Pickable_SeedTurnip

Pickable_Thistle

Pickable_Turnip

Thusly:
spawn Pickable_Dandelion 6
(The number being how many you want to spawn. )

Disclaimer: I haven't actually tried this. It may just spawn picked ones lying on the ground ready to be picked up rather than growing plants. It's worth trying in any case,