Sunday, June 9, 2013

Native Plants in Containers

Native plants really belong in vast tracts of preserved habitat. There they grow and thrive, spreading their roots as far as they need to and scattering seed on hospitable ground. Those of us that love native plants do appreciate having some of these wonderful and unique plants a little closer to us. We plant them in our yards just as we might incorporate any other garden plant. We even plant them in containers!
I am lucky to have 3 friends that are very talented in creating and maintaining plants in containers. All three of them happen to share my love of native plants as well and frequently use native plants in their containers. This year I am trying my hand at some containers in the hopes that some of their magic will rub off on me.

For my first attempts, I have tried some containers with only native plants and some that have native plants mixed with high quality annuals (that is, annuals that offer plentiful nectar such as Zinnia and Verbena). One container has a coastal native pineland hibiscus (Hibiscus aculeatus) and a non-native annual larkspur (Consolida ajacis). This is a full sun container and it sits on the front porch where otherwise no plants would be - take advantage of every bit of sun!

This year I decided to visit these friends and photograph some of their containers so others can see just how beautiful and versatile native plants can be. They each graciously offered some tips about creating containers.

At Debbie's house, I found containers for both sun and shade. Debbie's containers are scattered throughout the garden and she says that they are often in areas that get watered by the sprinklers (but she still has to water them if it is too hot or doesn't rain enough).

Here is a well established shade loving container with coral bells (Heuchera americana), heartleaf ginger (Hexastylis arifolia), pussytoes (Antennaria), partridgeberry (Mitchella repens) and an ebony spleenwort fern (Asplenium platyneuron).

Tip #1: Group plants together based on growing conditions - shade loving plants with others that like shade or all sun tolerant plants.

Another idea is to go for maximum impact by using a single type of plant in a container. Debbie's planter full of Iris cristata, a dwarf iris, is dramatic and beautiful even when it doesn't have flowers. All 3 of my friends use this approach to good effect.

Take that concept one step further and use similar looking plants. Until you get close up, you might not realize that this wreath that Sheri made uses small coral bell plants (Heuchera macrorhiza) and Sedum ternatum. Clusters of leaves on the Sedum look a lot like a single Heuchera leaf. It has the effect of maintaining different size perspectives even as the bigger plant matures. Click on the picture for a closer look.

Heuchera macrorhiza and Sedum ternatum

Of course combination planters allow you to create containers more like what people expect to see - something with a "thriller, a spiller, and a filler". Sheri's over the gate box planter has two fly poison plants (Amianthium muscitoxicum) for the thriller, with a combo of ferns and Heuchera for the fillers and spillers.

Tip #2: Use materials like sheet moss for a casual look or use colorful ribbons and garden art to make the containers more eye-catching.

Another very successful type of planter allows people to get up close to some of our very special natives - bog plants. Both Debbie and Marcia have very creative containers for pitcher plants and their boggy friends. This group of Marcia's containers sports blooms on both the pitcher plants and the sundews. Click the picture for a closer view.

Use containers without drainage to retain the water and use appropriate materials like peat inside. Marcia says plan to re-do those containers every few years as the peat breaks down and needs to be replenished.

Tip #3: when choosing containers consider weight (concrete versus resin), durability (plastic pots crack in the sun over time), and water retention (plastic holds water longer than clay and smaller holes take longer to drain).

Tip #4: Adding a tray/dish underneath can be attractive, protect your surfaces and keep pots watered longer.

The amount of plants you use in the pot should vary according to your taste. At right is a fully crammed planter that Sheri did for the flower show. If you plan on using the planter for several years, you might want to use fewer plants to allow for growth.

Tip #5: Improve moisture retention by topping the planter with mulch, finely ground bark or even clumps of moss.

Big pots are fun to use. Debbie has a number of pots with shrubs or small trees. She's had these longleaf pine trees (Pinus palustris) in deep pots for several years now. It's a very unexpected choice and very much her style!

Tip #6: Fill up the bottom of the pot with a variety of materials – old leaves or wood chips for smaller pots will add organic material; Styrofoam peanuts, plastic pots turned upside down or even empty plastic water bottles will fill up big spaces but add little weight. Lay a small sheet of landscape fabric over the filler to keep soil from spilling into the area.

The pot creates an artificial environment for the plant and we need to help it do well - particularly in terms of allowing excess water to move through it quickly enough yet still stay moist. Choose your planting soil components wisely.

Tip #7: Sheri recommends soil-less potting medium (if using a purchased potting soil, amend with fine ground bark mulch and sometimes perlite) because garden soil is too heavy and causes most plants to rot. Debbie uses a mix of potting soil, top soil and soil conditioner with a little extra perlite. Marcia prefers an equal combination of potting soil, soil conditioner (or very lightweight garden soil) and perlite. These recommendations do not apply to bog gardens.

Marcia chose a clay strawberry pot for this
arrangement of Heuchera and Lobelia.

Once you've created your container, it's time to take care of it. Watering is an important consideration both in terms of too much and too little!

Tip #8: Water the container appropriately based on the type of pot (clay pots dry out faster), the amount of plants in the pot (full pots dry out faster), how much sun the pot gets (pots in sun dry out faster), and the type of plants in the pot (some plants, like cardinal flower (Lobelia cardinalis), appreciate more water). Group pots together when possible as pots in odd places might get forgotten when it comes time to water them. Put a bright flag or ribbon on them to catch your eye.

Plants in the wild don't need fertilizer because their roots go far and the environment contributes decaying organic material or bug/animal poop to nourish them. Isolated away from those natural processes, you might want to help provide some nutrients.

Tip #9: Organic fertilizer like compost or slow release pellets would be a good choice as generally native plants are not heavy feeders.

After putting so much work into making pots, it's nice to have them stay around for a while if possible. Put them in a good spot for winter, especially clay pots which are sensitive to freezing temperatures, and revisit their contents come spring.

Tip #10: Continue the pots from year to year by removing overgrown plants if necessary and top-dressing with fresh mulch, compost or fertilizer.

If you'd like to try Sheri's wreath idea, I asked her for instructions: buy a wired wreath and line it with green sheet moss. Add the plants (she has used Tiarella in the past as well as just Sedum ternatum) and then pack more moss around the plants to keep them from falling out. The moss also helps to keep plants from drying out too quickly.


  1. Ellen this is amazing advice! I love it!

  2. Hi, Ellen-
    I'm doing a program on small scale natives/natives in containers for Botanical Gardens at Asheville. Would you mind if I use the pitcher plant containers and woodland garden container images (with attribution) in my presentation. Thanks.

  3. I am giving a presentation on native plants for small gardens in the Chapel Hill NC area and would like to include several of your images in a section on containers. I would actually send folks to this website for a fuller treatment of natives/container gardening. Let me know if this is ok? Thanks! Jen Cure, Cure Nursery