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Small Evergreen Conifers for Winter Gardening

 

Kohout’s Ice Breaker Korean fir has beautiful silvery and blue-green foliage that stands out in winter gardens.

I grow “miniature” or “dwarf” plants with caution*. Living and gardening in the Pacific Northwest, I have found that plants seem to grow larger than many of the plant tags indicate. I have had many experiences where plants get larger than the literature states and many gardening friends tell me that they have had the same experience. Perhaps it is our generally mild weather, rich soils, and regular rain that make for some nearly ideal growing conditions. (Sometimes, I tell myself that the plant does not know what the tag says!) So, growing guidelines can be helpful, and lists of truly tiny plants, in this case, evergreen conifers, useful.

Miniature and Dwarf Conifers Defined

Fortunately, the American Conifer Society has established size categories for conifers that attempt to address the continuous growth of supposed miniatures. While it is not perfect, it is a step in the right direction. The four categories are based on approximate growth per year and include:

  1. Miniature conifers: less than 1 inch
  2. Dwarf conifers: 1-6 inches
  3. Intermediate conifers: 6-12 inches
  4. Large conifers: more than 12 inches.

Of course, the region, climate, and culture will also play a factor in growth. Sometimes home gardeners have the opinion that a dwarf conifer will grow to ten-year dimensions and then stop growing. This is NOT always the case. Woody plants, including dwarf conifers, will continue to grow for the life of the plant–some more than others.

The Best Miniature and Dwarf Evergreens

Chamaecyparis obtusa ‘Hage’ is a truly tiny specimen plant that grows well in containers or rock gardens.

Recently, I visited the gardens of several different friends that grow small evergreens, and here are some truly slow growers that are recommended by the experts. (In my garden, I do not have many dwarf or miniature evergreens. Some that I have had, grew more than I had expected, and I gave them away.)

Miniature Korean fir (Abies koreanaKohout’s Ice Breaker’, Zones 5-8) offers brilliant silver and blue-green foliage throughout the year. This grows in a globose or rounded habit. The foliage has curled needles that show off the silvery-white undersides. Growth is 1-3 inches per year which makes this ideal for small gardens or rockeries. It was awarded the Award of Garden Merit from the Royal Horticultural Society, and in 2014 it was the American Conifer Society’s Conifer of the Year.

Dwarf Columnar Common Juniper (Juniperus communis ‘Compressa’, Zones 4-9) is a narrow, upright, evergreen shrub with foliage that is tightly packed with blue-green needles that are prickly to the touch. The foliage tends to turn to a copper-bronze shade in the winter. It can reach 1-5 feet after ten years and is another Award of Garden Merit winner.

Juniperus communis ‘Compressa’ has a neat, upright habit.

Miniature Hinoki False Cypress (Chamaecyparis obtusa ‘Hage’, Zones 5-9) is a compact pyramidal selection of Hinoki cypress. This foliage also turns bronze-ish in the winter in cold climates. After ten years, it might be about 16 inches tall.

Dwarf Black Spruce (Picea mariana ‘Nana’, Zones 2-8) has needles that are silver-blue-gray and very small that grow from thin branches that stay distinctive throughout their growth. As it grows, it develops a dense round habit, and in ten years it might reach 18 inches tall.

Dwarf Mugo Pine (Pinus mugo ‘Jakobsen’, Zones 2-8) is a clump-forming mugo pine with somewhat irregular branching. Specimens can look almost like bonsai. The needles are very dark green and held tightly together. It can reach 1-4.5 feet after ten years.

Dwarf Cedar of Lebanon (Cedrus libani ‘Hedgehog’, Zones 6-9) has very dark green foliage and forms a dense mound. The needles are prickly and can give the impression of a hedgehog. Expect it to reach 1-4.5 feet after ten years.

Whipcord is a stylish evergreen for small spaces.

Dwarf Western Red Cedar (Thuja plicata ‘Whipcord’, Zones 5-8) is one that I have in my garden, and I love it. I actually have two plants, and both are in matching urn-shaped containers. A description I once read about it said that it, “looks like a firework of stringy foliage”. That is a good description because the green branchlets radiate in all directions. It is low and mounding. After ten years it can reach 1-5 feet.

The selection of small growing evergreens is vast, so it is easy to begin to start collecting them. For those with small-space gardens or a deck, patio, or balcony, many of these make ideal potted plants that look good all year long.

*Writer’s Note: For the past few years, I have been fascinated with the genus Ginkgo. My garden property could certainly not contain a standard Ginkgo which could reach 50 feet or more. Several years ago, I bought Ginkgo biloba ‘Marieken’ as I had been told that it was a dwarf form. It is a beautiful plant with soft green leaves that have ruffled edges and turn brilliant golden yellow in the fall. After about five years, it has a width span of about 6 feet and that is not what I would call ‘dwarf’.

Create a Succulent Seascape Rock Garden

Well-chosen and placed succulents in picturesque rock gardens can have an underwater, seafloor appeal. The design key is selecting various dryland treasures with anemone-, coral-, and urchin-like forms and textures in shades of blue green, silver, gold and red. When arranged against a setting of bold rocks, lined with a ripple of pebbles and seashells, the effect is cool and inviting.

I created such a garden at my Delaware home to complement a stone and pebble patio being built along the south-facing wall of my 1920s Cape Cod house. The bed was constructed in four steps, and the plants were selected for their seascape appearance.

Most of the hardy succulents I chose for the project were purchased from the online nursery, Mountain Crest Gardens. Not only do they sell lots of hardy hens & chicks (Sempervivum spp.) and stonecrops (Sedum spp.), but they also offer hardy cacti (my favorite for spectacular spring flowers). And their succulents arrive thriving and ready to plant.

 

Rock Garden Materials

Nestle plants within crevices and gaps, making sure you leaves spaces for spreading succulents. (Sedum SUNSPARKLER® Dazzleberry and Sempervivum ‘Thunder’ shown)

My rock garden required the following materials:

  1. Sharp spade
  2. Trowel
  3. Large plastic tub
  4. Thick garden gloves
  5. Large rocks (my garden is 4’ x 5’ and required 10 rocks)
  6. Black Gold Garden Compost Blend and Black Gold Cactus Mix to amend the garden’s soil
  7. Pebbles and shells for topdressing
  8. Slow-release fertilizer
  9. Succulents

 

Bed Design and Construction

Once I had my rocks in place, I amended the fill soil and started planting!
  1. Sod and Soil Removal: The first step to preparing my garden was to remove the sod. Thankfully, my soil is high in organic matter, so removing the top layer of grass was relatively easy. I then skimmed a 2-inch layer of natural soil from the new bed layer to use as fill. I put the sod in a wheelbarrow for removal and the fill dirt in a plastic tub to keep the area tidy.
  2. Rock Placement: Then I placed my rocks. The natural dark grey and tan stones I chose are prevalent in my area, so they were a good fit for my yard. They also offered a pleasing color contrast to the plants and pebble. I set the largest rocks high against the concrete and stone base of my home for maximum visual appeal and gradually layered the smaller rocks down to patio level. I placed them close together at the top for a tight fit, so they would hold soil without erosion.
  3. Filling: Once my stones were in place, I mixed a liberal amount of Black Gold Cactus Mix and Garden Compost Blend into my fill. The final fill was pebbly and organic for excellent drainage and good water-holding ability. Then I filled in all the gaps between rocks, leaving enough space for my plantings.
  4. Plant Placement: Finally, I placed my plants, arranging them based on height, texture, and color, and prepared to plant.

 

Plant Materials

Most of my succulents were purchased online from Mountain Crest Gardens.

Aside from making sure that my plant selections would survive Delaware winters (USDA Hardiness Zone 7), I made sure they met a suite of aesthetic requirements. I chose a few taller textural plants, several cascading stonecrops, and other selections that were mounding and prickly. All are remarkably drought tolerant and tough, able to take the high heat and sun of the garden. My plant picks included:

Hybrid Prickly Pear (Opuntia ‘Coombe’s Winter Glow’, Zones 5-10). This hardy cactus has smooth paddles that lack the large spines of most, but beware those small spines! It has spectacular magenta blooms in late spring, and its paddles turn shades of rosy purple in winter.

Rosularia (Rosularia platyphylla, Zones 5-10): This spreading succulent looks like a tiny hens & chicks and creates a mat of sea-green rosettes.

Hens & Chicks (Sempervivum ‘Bronco’, Zones 5-10): This large hens & chicks has red and green rosettes that turn rich red in winter.

Hens & Chicks (Sempervivum ‘Thunder‘, Zones 5-10): The summer rosettes of this larger hens & chicks are grey-green tinted with lavender. In winter, they turn shades of deep lavender and rose.

Cobweb Hens & Chicks (Sempervivum arachnoideum ‘Pittonii’, Zones 5-8): This small hens & chicks has cobwebbed gray-green rosettes edged in dark purple.

Hens & Chicks (Sempervivum calcareum ‘Greenii’, Zones 5-10): The medium-sized, blue-green rosettes of this sedum have maroon tips.

Tiny Buttons Stonecrop (Sedum hispanicum ‘Blue Carpet’, Zones 5-9): This low, spreading sedum has tiny buttons of blue-grey foliage.

Hybrid Stonecrop (Sedum SUNSPARKLER® Dazzleberry, Zones 4-9): Purplish leaves and summer-long flowers of deep rose make this a winning sedum.

Hybrid Stonecrop (Sedum SUNSPARKLER® Jade Tuffet, Zones 4-9): This small, upright sedum has slender, dark green leaves and summer-long pink flowers.

Chinese Stonecrop (Sedum tetractinum ‘Coral Reef’, Zones 5-9): This pretty sedum has yellow spring flowers and bright green leaves that turn pinkish with age.

Adam’s Needle (Yucca filamentosa ‘Color Guard’, Zones 5-10): The gold-striped leaves of this 18-inch yucca are bright and bold.

My seascape rock garden includes stonecrops, hens & chicks, and other dryland succulents with coral-reef looks.

I put on my garden gloves and started planting the largest plants at the top, then moved down. During planting, I gently loosened the roots of any pot-bound plants, and dug a hole just big enough to ensure each plant’s roots were just at soil level. Then I sprinkled a small amount of slow-release fertilizer into each hole before planting. Once all of the plants were in the ground, I covered the soil with light pebbles and placed seashells here are there for a complete seascape look.

 

Garden Development

In just a couple of months my bed was blooming and growing, just as anticipated.

Within just a couple of months, my new garden started to take shape. The prickly pear put on new pads, the stonecrops and hens & chicks started to spread, and the SUNSPARKLERS began blooming beautifully. Come next summer, the full seascape effect should be in full sway, adding sunny, succulent interest to my new patio!