Perennials — in Containers?

close up of gray planter with red begonias, ferns, and fuschia

You might not normally think about using perennials in containers, but I encourage you to think outside the (planter) box.  I’ve seen a lot of photos of planters lately using heuchera and hosta lately, and I love them!  Perennials only cost a few dollars more than most perennials, and if you dig them out of your garden, they are free.  In the fall, you can choose to plant them in the ground, overwinter them right in their pots, or pretend they are just another annual and pull them out.  If you want to give it a try this year, here are some things to consider:

  1. Choose well behaved perennials. By that I mean choose ones that don’t get overly large or aggressively spread everywhere.  Smaller perennials that make neat mounds, are tall and skinny, or ones that climb or trail are good choices.
  2. Choose perennials with great foliage. Since perennials usually don’t bloom all summer, choosing ones that look great even when they aren’t flowering is a must.  Think of the flowers as a bonus, not the most important thing.
  3. Keep in mind that potted perennials often won’t grow to their full potential. They are a little constricted and tend to stay a little smaller in pots than they would if planted in the ground, especially the taller ones.
  4. Use big pots. Perennials often have larger root systems than typical annuals, so they need a little more room. And if you do overwinter them in their pots, the extra soil will provide a bit more insulation from the cold.
  5. Make sure your perennials won’t get waterlogged by using a lightweight potting soil mix and choosing a pot with good drainage holes.

 

If you want to overwinter your perennials in their containers, these tips may improve your chances of success:

  1. Use perennials that are hardy to about two zones colder than where you live. We are in zone 5a, so choose plants that are listed as being hardy to zone 3.
  2. Use pots that can withstand Wisconsin winters. Clay and ceramic are likely to break as the soil inside expands and contracts with the changing temperatures in late winter.  Fiberglass, plastic, and other composites are good choices, as well as whiskey barrels and other wooden containers. 
  3. Bring the pots into an unheated garage, or another sheltered area. The east side of a building usually provides good shelter from winter winds.
  4. If you are keeping them outdoors, cover the plants with evergreen boughs or leaves.
  5. Don’t keep them on a deck or concrete patio where the cold can easily come from underneath.
  6. Tip the pots on their sides. This makes sure that the roots won’t get waterlogged during early spring weather, where there is usually a lot of moisture, and their soil is still partially frozen.
  7. If you have a lot of pots, group them all together with the most sensitive plants in the middle of the bunch.
  8. Partially burying your pots in your flower bed is another good option.
  9. Or just leave them just where they are. Take your chances with Mother Nature and savor the sense of possibility that comes with spring — wondering if they made it through. Gardening is a form of gambling in some sense.  Go with it and enjoy!

 

Which perennials tend to do well in pots?  In addition to the previously mentioned heuchera and hosta, try yarrow, smaller clematis, coneflowers, ferns, salvia, catmint, lavender, sedum, astilbe, or lady’s mantle.  If you give it a try, we’d love to see photos of your containers!  Send your photos to bridget.rolek@pleasantprairiegreenhouse.com, message us via Facebook, or simply tag Pleasant Prairie Greenhouse in any Facebook or Instagram post.