This idea has worked for me for many years. I started with one but now have over a dozen !
Buy a sturdy tomato cage & vinyl coated chicken wire fencing & coco coir bowl shaped liner. Drive the cage into the ground in your chosen area (a permanent spot for this year's growing season). Form a bowl out of the vinyl chicken wire and fold over the top of the tomato cage to secure firmly. Line the bowl with coco coir or cloth or landscape weed barrier fabric. Plant your annuals of choice.
Tips:
Push that tomato cage into the ground accurately & deep, those prongs will be supporting the planter surprisingly well on windy days.
When forming the chicken wire bowl-make it deep rather than shallow, it will retain moisture better.
The planter & bowl can remain fastened together for off season storage (I hang mine, prongs facing up, on nails way up on the shed walls)-they last for years if you buy a well made tomato cage.
When buying the tomato cage double check the welded joints.
This next picture shows two planters in full shade located in an otherwise 'no bloom' area of the garden. Begonia corms were directly planted into the soil of one planter. The planter in the foreground (hard to see the planter!) was planted with a well established lofa plant. See how nicely it cascades over & down? So...when buying tomato cages - think big & little, tall & short cages.
Succulents seem to really love being in these planters. A real showpiece when you add a few sparkling rocks or fairy ornaments.
Oh, I can already tell your gardener's brain is smoking with ideas !
Craw ! A thoughtful gift that I will plant !
!!! I have very little garden space so this is just the thing! Also, I'm thinking that it's a great fix for places where I have summer-blooming plants but would also love to have something in there for the spring! These will be great to have while those summer-bloomers are just starting to peek through the soil. Plus, all the parts are available at our local box store! I can pick up decent tomato cages for only a dollar or two! 
