You will need green and brown worsted weight yarn and a 3.5mm hook. At the end of each row chain 1 and turn.
Begin with 25 Foundation Half double Crochet in green yarn. If you need any help with Foundation Stitches please refer to this post where I provide a detailed tutorial.
Make a total of 7 rows, including the foundation chain, of HDC in green.
For the next 6 rows we will make the turn portion. To get crisp color changes pull up the new color one loop before. HDCx13 in green yarn, then change to brown. HDCx12 in brown yarn. Each of the next 5 rows will have 1 additional brown stitch and one less green until there are 17 brown and 8 green.
HDCx8 in green yarn. Then change to brown, carry the green working yarn, and HDCx9 in brown. Change to green, do not carry the brown working yarn, and HDCx8.
Make 7 total rows of HDCx8 in green, HDCx9 in brown, and HDCx8 in green.
Fasten off and weave in ends!