Normal ?...Well, I think it's surprising just how hardy these plants actually are, I've seen these plants growing out of old wall and cracks in paving,surviving some pretty harsh weather!
The snapdragon or antirrhinum is an old cottage garden favourite grown since victorian times which was introduced from warmer climes as a garden plant and in gardening terms it's considered as a 'half hardy annual' in our usual climate. They are usually taken out after the growing season, as many varieties are prone to the fungal disease known as rust and this practice would hopefully break the cycle. Good luck and Happy New Year. Tbird+