by Heather McCargo

Window boxes in BarcelonaMy family lived in Barcelona a few years ago, and I was smitten with the ubiquitous Spanish balcony. Almost every urban apartment had one. They provided a much needed connection to the outdoors for apartment dwellers and a great view of the vibrant street life below. Many balconies were filled with pots of plants, and though they were often the same mass produced annual flower and foliage plants now grown world wide, I saw the potential to bring nature into every urbanite’s dwelling with species native to the area. These indigenous plants would attract the birds and pollinators that still reside in the wild lands on the outskirts of the city.

Here in New England, balconies are less frequent, but many urban apartment dwellers have a small decks, doorways with steps, window boxes or access to a piece of rooftop that gives them the opportunity to grow plants outdoors. I imagine corridors of natives in planters and pots, with butterflies, bees and hummingbirds flitting up and down the streets, foraging at ground level and rising up multiple stories, mimicking the vertical habitat of a cliff.

If you are an urban dweller who has no piece of earth to call your own, growing natives in pots is a great way to get to know some of these plants despite your landless situation. And, if you need to move, just bring them along. These plants will become your family, and will make each new apartment feel like home and give you a daily connection to a piece of nature.

How to Do It

Many native plants grow well in pots. Small shrubs and trees add year round interest, and the woody branches provide overwintering habitat for small fauna. Some may eventually outgrow their pots and need to be planted in the earth, but in the meantime you can be enjoying their presence.

Native perennials can be grown as a mass of a single species or mixed with others with similar requirements. Ferns and native grasses are also dramatic in pots.

Very tall perennials sometimes get too leggy to look good in a pot, so choose species under 2 feet. That said, with a very large pot, some large perennials like Joe-pye weed or perennial sunflowers will look great.

Potted plantsGeneral planting principles:

The bigger and deeper the pot, the stronger the plant and the less time between watering. Pots can be hand made cedar boxes, clay or cement (heavy), plastic, fabric grow bags, old tin buckets or trash cans (with drainage holes). The possibilities are many, depending on your imagination and budget. Large pots begin at 18-24” wide by the same depth (or larger, if you have the space). Medium pots are 14-18” and small pots 12”.

Daily watering in summer is the most demanding chore of plants in pots. It can be pleasurable but can not be neglected. If you need to go away for a few days and do not have a reliable neighbor to water while you are gone, there are many creative solutions.

Organic potting soil grows the healthiest plants, but any pot mix can be improved with compost or a regular watering with liquid seaweed. If weight is an issue, perlite (expanded volcanic rock that looks like little white balls) will lighten the mix.

Mulch the soil in the pots with leaf litter, rotted bark, or sand/fine gravel for dry land species. Natural mulches protect the roots and provides habitat for overwintering and ground nesting pollinators.

Planters in exposed locations may need to be protected in the winter with an insulating tarp, depending on what you are growing in them.

Here is a small sampling of some natives to grow in planters:

For a shady balcony

Plants in potsWoody shrubs in large pots
Witch hazel Hamaelis virginiana
Highbush blueberry Vaccinium coryumbosum

Perennials for medium pots
Ferns – Christmas fern Polystichum acrostichoides, Maidenhair fern Adiantum pedatum, Lady fern Athyrium felix-femina
Solomon’s seal Polygonatum biflorum
Cranesbill geranium Geranium maculatum
Baneberry Actaea rubra or A. pachypoda
Jack-in-the-pulpit Arisaema triphyllum
Columbine Aquilegia canadensis
Jacob’s ladder Polemonium reptans*
Small’s penstemon Penstemon smallii*
False Solomon’s seal Maianthemum racemosum
Blue lobelia Lobelia siphilitica
Cardinal flower Lobelia cardinalis
Wood asters– Symphotrichum cordifolium, Eurybia divaricata, E .macrophylla
White snakeroot Ageratina altissimo

Small perennials for window boxes or small pots
Woodland stonecrop Sedum ternatum
Alum-root Heuchera spp.*
Violet Viola blanda, V. cucullaria,
Wintergreen Gaultheria procumbens
Wood phlox Phlox divaricata *and P. stolonifera*

Potted plantsFor a mostly sunny balcony

Small trees in large pots
Shadberry Amelanchier canadensis, A. laevis
Black haw Viburnum prunifolium*

Shrubs for medium pots
Viburnums Viburnum cassinoides, V.dentatum
Coastal sweet-pepperbush Clethra alnifolia
Yellow bush-honeysuckle Diervilla lonicera
Mountain laurel Kalmia latifolia
Fothergilla Fothergilla gardenii*
Fetterbush Leucothoe axillaris*
Virginia sweetspire Itea virginica*
Hazelnut Corylusamericana, C. cornuta

Perennials in medium pots
Swamp or common milkweed Asclepias incarnata, A. syriaca
Canada anemone Anemone canadensis
Bleeding heart Dicentra eximia*
Heart-leaved Alexander Zizia aptera*
Rose coreopsis Coreopsis rosea
Coneflowers Rudbeckia hirta, R. triloba *or Echinacea species*
Cardinal flower Lobelia cardinalis
Foxglove penstemon Penstemon digitalis
Asters Symphotrichum laevis, S. oblongifolia*
Wreath goldenrod Solidago caesia
Grasses: Switch panicgrass Panicum virganum ,Wild oats Chasmanthium latifolium*

In a hot, sunny exposed balcony

Woody plants for medium to large pots
Beach plum Prunus maritima
Chokecherry Aronia melanocarpa
Low blueberry Vaccinium angustifolium
Bayberry Morella pensylvanica
Wild rose Rosa virginiana, R. carolina
New Jersey tea Ceanothus americanus
Meadowsweet Spirea alba, S. tomentosa
Bearberry Arctostaphyos uva-ursi

Perennials for small to medium pots
Wild strawberry Fragaria virginiana
Violets Viola pedata, Viola adunca
Blue-eyed grass Sisyrinchium spp.
Pussytoes Antenaria spp.
Bunchberry Chamaepericlymenum canadense
Sundial lupine Lupinus perennis
Scotch bellflower Campanula rotundifolia
Butterfly milkweed Asclepias tuberosa
Nodding onion Allium cernuum*
Foxglove Penstemon Penstemon digitalis, Penstemon hirsutus
Black-eyed Coneflower Rudbeckia hirta
Dryland asters Lonactis linariifolius, Symphotrichum laevis, S. oblongifolia*
Goldenrod Solidago puberula, S. sempervirens
Little bluestem grass Schizachryium scoparium

*These species are native to eastern North America but not the state of Maine

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