Dreams dictionary: Thorns
Dreams dictionary: Interpretation 1
To see thorns in your dream suggest that there is a prickly situation that you need to overcome. Thorns also symbolize past trauma or some physical suffering. You may be putting up your defenses. Also consider if someone is being a pain or a "thorn by your side.
Dreams dictionary: Miller Dream Interpretation
To dream of thorns, is an omen of dissatisfaction, and evil will surround every effort to advancement. If the thorns are hidden beneath green foliage, you prosperity will be interfered with by secret enemies.