Textarea

To use the custom form group inputs you don't need to import the custom made component, you can use it like this:

<md-field>
  <label>About Me</label>
  <md-textarea v-model="aboutme"></md-textarea>
</md-field>
<script>
  export default {
    data: () => ({
      aboutme: null
    })
  }
</script>

Note: For more details about the textarea please see the Input & Textarea section from vuematerial.io