<div class="container" id="container">
  <div class="item">Potato</div>
  <div class="item">Sprout tomato</div>
  <div class="item">Gumbo beet greens</div>
  <div class="item">corn soko</div>
  <div class="item">endive gumbo gourd</div>
  <div class="item">Parsley shallot courgette tatsoi</div> 
  <div class="item">pea sprouts fava bean</div> 
  <div class="item">collard greens</div> 
  <div class="item">dandelion okra wakame</div> 
  <div class="item">tomato</div>
</div>

body {
  padding: 20px;
  font: 1em Helvetica Neue, Helvetica, Arial, sans-serif;
}

* {box-sizing: border-box;}

p {
  margin: 0 0 1em 0;
}

.container {  
  border: 5px solid rgb(111,41,97);
  border-radius: .5em;
  padding: 10px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  width: 500px;
}

.item {
  padding: 10px;
  background-color: rgba(111,41,97,.3);
  border: 2px solid rgba(111,41,97,.5);
  flex: 1 1 auto;
}