Spring

• Mix early bloomers for the first colors of spring and continue planting as the weather warms to keep urns bright with flowers. Violas and primulas are pretty and hardy. Transplant potted hyacinths, coral bells and early crocus. Plant a whole urn full of daffodils for a mono-color garden. Tuck low- to mid-height tulips in a mixed planting around April as it gets sunnier, and ring the urn with pansies that will flower until the real heat wilts them in summer.
  
  

Summer

• Petunias and trailing petunias can thrive in a concrete urn placed in a sunny spot and keep their colors bright all summer and into the fall. Mix them with green Euphorbias and add Euphorbia diamond frost, which erupts into fragile white flowers that will survive some drought or missed watering dates. Gerbera daisies in the center of the pot will add height and tremendous color. Verbena comes in many colors and the plants will spill over the rim of the urn and cascade down the side. Avoid flowers with very tall stalks or stems like many daylilies, as they are difficult to balance visually in the urn. Mounding is a good look but spiky and tall doesn't work.
  
  

Grasses

• Planting a concrete urn with ornamental grasses is a striking treatment. The grass mounds high over the urn and trails loosely over the side. It often changes color with the seasons, going from green in summer to red or pink in autumn and brown in winter. Winter grass is architecturally interesting and you should leave it in place to avoid having bare planters. Purple fountain grass is colorful and fountain-like in shape so it turns your urn into an ice cream cone. Japanese blood grass first grows green and then turns blood red.
  
  

Herbs and Veggies

• Why not grow edibles in your concrete urn? Leaf lettuces and spinach are fat or bushy and green. Radishes will grow in a large, deep urn. Miniature squash are attractive when green, have briefly charming flowers and produce interesting and tasty fruit. Marigolds and nasturtium protect vegetables from garden pests and mix well with the greenery. Parsley, dill, cilantro, basil and mint will all thrive in a container as long as you are attentive to watering. Try tiny cherry tomatoes, green onions and chives. As an added bonus, the urn removes the veggie patch from some of the more common ground insects and pests.