The basic pattern would also be great to use on a washcloth or dish towel, or work a bunch on a longer knit piece to make a table runner.
What you needFor the solid coaster I used about 10 yards for the smaller version and 14 yards for the larger version in Red Heart With Love in color Lettuce
For the green and white coaster I used 22 yards total of Red Heart Super Saver
one pair size 7 US (4.5 mm) knitting needles
Shamrock Chart (below)
Gauge is not all that critical for this project, but I got 16 stitches and 23 rows per 4 inches/10 cm in Stockinette Stitch on the solid color coasters and 18 stitches and 23 rows per 4 inches/10 cm on the green and white coasters.
Finished solid color coasters are 4.5 inches/11.5 cm tall and 5.5 inches/14 cm wide for the smaller version and 5.5 inches/14 cm square for the larger version.
The green and white coasters are about 5 inches/13 cm wide and 5.5 inches/14 cm tall.
Instructions for Solid Color Coasters:
Cast on 23 stitches.
Work in Seed Stitch (*k1, p1. Repeat from * across) for 4 rows.
Keeping the first 4 and last 4 stitches in Seed Stitch throughout, work in Stockinette Stitch for 2 rows for the smaller coaster and 5 rows for the larger coaster.
Begin chart, working the shamrock in Reverse Stockinette Stitch (purl on the right side, knit on the wrong side).
Once chart is complete, work in Stockinette Stitch for 2 rows for the smaller coaster and 5 rows for the larger coaster.
Work in Seed Stitch for 4 rows.
Bind off and weave in ends.
Instructions for the Green and White Coasters:
Work as for Solid Color Coasters, but work the chart in the contrasting color. These are only shown in the larger size, but you could work them smaller, too, if you wanted, by working fewer rows of Stockinette Stitch before and after the chart.