Toxic Growth

Summon a deadly growth of thorns in front of you. Enemies caught in the growth must make a dexterity saving throw against DC of 13. On a failed save, those caught in the growth are trapped. The creature still takes the take toxic damage regardless of being saved. This spell can be imbued into a projectile, such as arrows and crossbow bolts, and can grow them at the maximum range of the weapon the arrow or bolt is fired from. Wherever the arrow lands is where the thorns grow. The range of the growth is a circle with a 5-foot radius. The growth itself does 1d4 piercing damage and 1d8 poison damage. To calculate damage: roll 2d6, half is piercing, and half is poison. The growth lasts 1 round.

While the spell cannot be upcast, the spell upgrades with player level, regardless of whether the player is multiclass'd. Here are the upgrades:

1. At player level 5, the growth now has a 10-foot radius.
2. At player level 8, you can utilize the spell twice in the same action. 
3. At player level 11, the dexterity save DC is now 16.
4. At player level 14, the growth now remains on the field for 3 rounds; the damage ticks at the start of the caster's next turn (roll damage every round). Creatures can remake the dex saving throw at the start of their turn as a bonus action. 
5. At player level 17, all damage from the growths is doubled; roll like normal, double final value.