Thursday, December 13, 2012

Evergreen Perennials In New England, Not Just A Flower!

I started working professionally in the horticultural field while living in Northern California, and the range of evergreen plants and perennials was unbelievable.  Without the freeze, plants and gardens could look great year-round.  There was always a down period in the winter, but that is when I picked my Meyer Lemons and Clementines.  Many of the wonderful sub-tropical annuals that we use in New England are actually perennial in warmer climes like California and some can deliver year-round interest.

So often we think of perennials in New England as plants that flower in the summer and then leave big gaping holes in our garden, but it doesn't have to be that way.  Following are some images and summaries of perennials that deliver during the off-season too.  It is not an exhaustive list...just some of my favorites.  These plants are great to use around entrances and walkways where there is year-round traffic and a desire to keep the gardens interesting and not beds of mulch.

Heuchera v. 'Citronelle' in front of Epimedium grandiflorum
Epimedium grandiflorum 'Lilafee' (Barrenwort)
Another BFF perennial that has delicate, early flowers and has rugged foliage that often goes through a range of colors during the season.  Here it turns a nice bronzy-red in the fall.  This image was also taken a few days ago.  Another great plant for massing as it spreads and looks great most of the year until  it flowers early in the spring and sends out a new flush of foliage.  It prefers shade, but will perform in all but the hottest sun.

Alchemilla mollis
Alchemilla mollis (Lady's Mantle)
This is one of my favorite perennials for its versatility, as I have mentioned before, and it looks good until the snow covers it up.  Not the sexiest plant, but in groupings it spreads and self-sows and has beautiful scalloped leaves.  The chartreuse flowers are fantastic and last for two months in the late spring.  This image was just taken in December and they really keep space filled in the beds when most other perennials have been gone for a month or two.  It performs in shade and sun and will need ample moisture if in a hot sunny space.  The flower display will dissipate in deep shade.

Silver Scrolls in mid-December
Coral Bells have been around forever, and many have been of marginal quality, but I love the new villosa hybrids that are quite vigorous.  The Citronelle plants above, in front of the Epimedium, were small divisions in the early summer and quickly became full-sized.  There are so many shades and colors to choose from (some are quite unnatural looking) that they form great masses of foliage with varying textures.  If you trim them up a little they will look great all year and they do well in sun to shade but prefer a little shade.

Dianthus in front of the border
Dianthus gratianopolitanus 'Firewitch' (Pinks)
Dianthus is a full sun-loving perennial that carries its grass-like foliage year round.  Many of the newer cultivars will flower throughout the season after their big spring flush.   Don't spend much time caring for this plant, it seems to thrive in hot sun and dry soil.  Cut back the spent flowers and it will spend some energy on its foliage and flower sporadically.  Great edge of the border plant and along walls and pathways as it spreads and spills over.  This picture was taken yesterday.

Helleborus orientalis in Bloom (Van Berkum)
Heleborus orientalis 'Royal Heritage' (Lenten Rose)
This is such an under-utilized perennial that can look great during the off-season and flowers early in the year with the spring bulbs.  It takes a little time for these plants to get established, but when they are, the glossy, leathery foliage is a wonderful textural addition to the perennial bed.  They come in a broad range of colors from white, yellow, pink and reds to maroon and 'black'.  The above link refers to a comprehensive article on Hellebores by Plant Delights Nursery, one of the finest perennial nurseries in the country.

Bergenia turning in fall (Van Berkum)
Bergenia cordifolia (Pigsqueak)
You have to love a plant with the common name of Pigsqueak.  Another decidedly un-sexy plant, but it forms wonderful mats of heart-shaped(cordifolia means heart-shaped foliage) leaves, when planted in groups. The foliage turns a bronzy color in the fall.  It also flowers early in the season with the spring bulbs, and prefers a fair bit of shade in woodland settings.  A nice surprise for those who think perennials are just for the summer.

Sedum reflexum a blue and yellow  (Stonecrop)
There are so many forms of Sedum, from the upright stalwarts of the fall garden to the creeping evergreen groundcovers here.  These have been in their stone container outside for five years and look great with an occasional clean-up.  In sunny beds they will form beautiful mats of foliage year round.  They all have a great flush of flowers in the summer to add to an already interesting foliage plant.  They like it hot and dry and thrive on neglect. Who would want more!

When designing with perennials, we are always looking for the color and pizazz they provide, but often we overlook the value their foliage can provide, especially in the off-season when most perennials are in dormancy.  These good foliage traits can allow you to use perennials in the most visible areas and not worry about holes in your beds in the off-season.  Often these plants are at their worst in the spring, but if you intersperse with spring bulbs, they will take your eye off the plants as they regenerate for the new season.

Pieris x 'Browers Beauty' a favorite shrub in Fall and Winter
for it flower buds that will open in spring and the foliage color

I loved this photo from two weeks ago of Acer griseum in color by
the front door.

1 comment:

  1. I agree with all your choices! I grow all but the cordifolia in my own garden, and i think I must add that one too. I really like your heuchera/epimedium combination.