Understanding The Growing Requirements of Native Plants

By Chief Horticulturist David Salman

Incorporating native plants into your landscape and landscape designs can be a very gratifying experience.The key to success with native plants is learning where the plants are from to understand the climate and growing conditions of their native habitats.

Many of the non-native perennials that dominate our landscapes have been widely cultivated for many years in Europe and the United States, and have very wide tolerances as to the type of climates they enjoy and their cultural needs in the garden. This is in large part because over the years, plants that were difficult to grow and propagate using traditional methods disappeared from the trade.

Many native plant introductions are very new to the gardening public, and their cultural needs less understood. However, we are already finding that many natives are also easy to grow and propagate, and have become common in gardens across the country. Our general knowledge about a native plant's soil preferences, sun exposure, moisture needs, and tolerances must be understood. Once you know your native plant's needs, you can easily grow resilient, beautiful plants in your garden.

• Gardening With Native Plants: Moisture Compatibility
• Gardening With Native Plants: The Right Soil
• Native Plants of the Midwest and Northeast
• Native Plants of The Great Plains

The compatibility of a given native plant to your local area is highly dependent on that plant's need for moisture. The amount of precipitation that plants receive in their habitats is a very important piece of cultural information. Looking at a precipitation map of the United States the pattern shows us that, in general, as we move west from the eastern seaboard toward California the terrain becomes drier and drier. Thus plants native to the various desert regions of the western United States will not be well suited to average garden conditions in moist midwestern or eastern states. Ohio. However, in my experience, a native plant from Ohio, for example, may do fine in Santa Fe's high desert climate if given enriched soil, sufficient irrigation, and afternoon shade to avoid heat stroke.

Soil chemistry and soil drainage are two other critical factors in plant growth. My experience has been that native plants from the East and Midwest make the transition to western growing conditions more easily than western natives transition the other direction. It would seem that many western plants are more specialized and closely matched to the harsh, dry conditions of their habitats and are less adaptable to richer soils and more moisture. But like all generalizations there are notable (and often surprising) exceptions.

• Western soils tend to be very mineral (low in organic materials) and alkaline.
• Many Midwestern soils are humus rich and their pH ranges from neutral to acidic.
• Eastern soils can be much more variable, but in general are acidic.
  
  

Moving western natives to eastern gardens: Gardeners with acidic soil conditions must raise the soil pH using additives, such as lime and wood ashes, to provide the alkaline conditions required by many western natives. Many western natives also need higher trace mineral levels and benefit greatly by using trace mineral fertilizers like Planters II (rock dust in organic gardening circles).

Moving eastern natives to western gardens: moving eastern plants to the west can be accomplished using lots of greensand and soil sulfur to bring down the soil alkalinity. However, acid-loving plants are very difficult to grow long-term without constant acidification efforts and use of rainwater to irrigate. (Many western regions have very hard, alkaline well water.)

Soil drainage is a critical but often overlooked factor in growing native plants.

Moving western natives to eastern gardens: Many western natives require dry, fast draining soil. When moving western plants to wetter climates, sandy and sandy/loam soils provide drier, faster-draining conditions than clay. It is more challenging when we move dry clay lovers from west to east than vice versa. Eastern clay soils that stay wet from plentiful rain and snow will be deadly for dry clay lovers from the west. A sand/gravel/clay soil mixture used in a raised bed or berm is often the best solution to this dilemma. Learn More: How To Create Well-Drained Soil

Moving eastern natives to western gardens: Natives that like moister, high humus soils can be accommodated out west by incorporating generous amounts of compost and Broadleaf P4 water retaining crystals into the soil, and irrigating more frequently. Clay loving plants are common in all areas of the United States.

I'm not as familiar with native plants from the Midwest and eastern United States, as I don't often have the opportunity to see and study these plants in their native habitats; so I look to the many native plant experts in these regions and trial their introductions in Santa Fe. Interestingly, these regions offer many summer- and fall-blooming species that are invaluable for coloring the garden when the many late spring and early summer blooming natives have past. (Remember, the compatibility of a given native plant to your local area is highly dependent on that plant's need for moisture.)

• Solidago (Goldenrod): Solidago rugosa 'Fireworks' and S. sphacelata 'Golden Fleece' are two standouts valued for their late summer yellow flowers. 
• Asters: The novae-belgie and novae-angliae Asters from back east are parents to a huge number of hybrids and selections. A favorite selection originally found in the wild is Aster n.-a. 'Purple Dome'. An aster relative that has proven itself as a valued source of long lasting cut flowers is the white daisy flowered Boltonia asteriodes "Snowbank". 
• Eupatorium (Joe Pye Weed) (found in Unique Plants) can be a difficult genus in the high, dry desert of northern NM, but Eupatorium maculatum "Gateway" is a wonderful exception. It still needs regular irrigation and rich, moisture-retentive soils but will grow well in non-bog conditions.
• The same is true for several of the Monarda (Bee Balm) cultivars like Monarda x 'Violet Queen'. This hybrid has outstanding mildew tolerance and thrives in drier conditions. 
• Liatris (Blazing Star or Gayfeather): Liatris ligulistylus is a superb Gayfeather with long showy purple flower spikes.
• Of course the Coneflowers (Echinacea) reign supreme in the summer garden. Echinacea purpurea and its various cultivars ('Magnus' and 'White Swan') are well known. Less familiar but equally deserving a place in the garden are the rare yellow flowered E. paradoxa (Ozark Coneflower) from the Ozarks of Missouri and Arkansas, and the graceful E. angustifolia, native to the prairies of the Midwest and eastern Great Plains.

Almost all of the above natives are highly valued nectar sources for adult butterflies.

The Great Plains provide a treasure trove of tough but beautiful native plants. These plants are adapted to surviving extremes of temperatures and moisture as well as grazing animals. They favor well-drained, not-too-rich soils with a neutral to alkaline pH. Their natural climatic precipitation arrives during the winter, spring and sporadically during the heat of the summer months.

• My favorites include the duet of Scutellaria resinosa, a mounding blue-flowered beauty and Hymenoxys scaposa (Thrift-Leaf Perky Sue), a gray, thread-leaved little gem with yellow daisies.
• I like to plant these species with plains cacti like the magenta flowered Coryphantha (Escobaria) vivipara and the yellow-green flowered Echinocereus viridiflorus. Our native cacti are some of our most spectacular but overlooked wildflowers. I encourage their inclusion when planting other xeric (drought resistant) perennial native flowers.
• Callirhoe involucrata (Poppy Mallow), a flowering perennial from the Great Plains, grows well in a wide range of soil types.

Phemerosa calycinum: A Native Garden Favorite

Another outstanding succulent from the plains is the everblooming, magenta-flowered Phemerosa calycinum (Talinum), also known as Fame Flower. This quirky little native's odd behavior is an excellent example of why some folks avoid native plants, thinking they are too hard to grow—but it's actually a showy, easy-to-grow plant once you understand its needs. I recommend it to everybody.

Talinum likes dry, sandy or sandy/loam soils. It is very slow to wake from its winter slumber, waiting until the late spring frosts have past. It also withers (goes dormant) before frost, using short days as its dormancy trigger. If you didn't know better you would think the plant either died suddenly in the fall or didn't make it through the winter. However it easily survives the cold winters as a shallow rooted succulent crown (stem at the junction of the roots and above ground stem) that looks like a fat twig. Be patient in the spring because it returns to get bigger and showier every year.

Other Native Garden Favorites From the Great Plains

Other indispensable flowering perennials from the Great Plains include:

• Berlandiera (Chocolate Flower)
• Calylophus serrulatus (Sundrops)
• Callirhoe involucrata (Poppy Mallow)
• Liatris punctata (Dotted Blazing Star)
• Various grasses like Schizachyrium scoparum "The Blues" (Little Blue Stem) and Panicum virgatum 'Prairie Sky' (Switchgrass).

The Great Plants for the Great Plains program, sponsored by the Nebraska Statewide Arboretum, and supported by Nebraska Extension nurseries that grow and propagate new finds, is an excellent program devoted to bringing natives for the plains into cultivation.

Learn More About High Country Gardens Native Plants

• Agastache Introductions: Superstars of the Perennial World
• Growing Blonde Ambition Grass Across The Country: A Unique Native Ornamental Grass 
• Heroes Of Horticulture: Plant Explorers

Text by Founder and Chief Horticulturist David Salman. © All articles are copyrighted by High Country Gardens. Republication is prohibited without permission.