Winter’s Green

Recently in Around the Grounds, we featured native shrubs that add splashes of color to the winter landscape. (Read our Winterberry and Red Osier Dogwood posts here.) While brilliant berries and colorful bark are important for winter interest, evergreen shrubs are the backbone of the garden, providing structure throughout the year. And, as we remind ourselves, green is a color, too! 

Unfortunately, our suburban landscapes tend to use a very limited repertoire of evergreen plants. We think there are better and more interesting choices than boxwood and taxus for residential foundation plantings. Take a look at some of the evergreens we’ve used at the Nature Center:

Inkberry shrubs define the edge of our patio garden all year

One of our favorites is the native Inkberry (Ilex glabra). Inkberry resembles boxwood, with similar dark green, shiny leaves. And, like boxwood, it can be pruned into a hedge, or a sphere, or any shape Edward Scissorhands might fancy. We prefer to let it take a natural, rounded shape with dense branches as hiding places for songbirds.

Inkberry looks similar to boxwood or Japanese holly, but is hardier

Unlike boxwood, Inkberry is adapted to our climate because it is native here. Boxwood originated in southern Europe, northern Africa, and western Asia; all climates very different from ours. Gardeners here are advised to wrap boxwood with burlap in winter to protect it from cold, wind, and salt – not a great look for “winter interest.”

Unlike Inkberry, boxwood needs protection from winter weather

Inkberry is not only cold-tolerant, even to temps below zero, but it enjoys our acidic soil and doesn’t mind sitting in water after heavy rainfalls. It is deer-resistant and salt-tolerant. It does prefer full sun, but can handle some shade. The straight species will get 6 to 8 feet tall, but it can be sheared and shorter cultivars are available.  

Heavily-pruned boxwoods

We’re not sure why so many suburban dwellers like plants pruned into ball shapes, but we do know a native evergreen that will take that shape without any help! Growers have developed cultivars of our native Arborvitae that grow naturally into a ball shape without pruning. 

Globe Arborvitae grows in a spherical shape

Arborvitae (Thuja occidentalis), also known as Eastern or Northern White Cedar, is very familiar as a tree; often used as a hedge or screen. It is native to our region and has wildlife value as a nesting site and seed supply for birds. Be advised that it is also famously attractive to deer. Some sellers of Globe Arborvitae claim the shrub is more deer-resistant than the tree, but we planted it close to a busy patio just in case. There are numerous cultivars of Globe Arborvitae available, with varying maximum sizes and slight color variations. Because we always prefer native plants, we would choose this little shrub over either boxwood or taxus – and we don’t have to prune it!

On our patio, Globe Arborvitae echos the rounded form of Inkberry 

Another delightful evergreen shrub developed from a native tree is Pinus strobus ‘Soft Touch’ or Dwarf Eastern White Pine. ‘Soft Touch’ makes a great foundation plant. It is slow-growing, eventually taking a flattened shape no more than 2 feet tall, and wider than it is tall. It stays a lovely bright green all winter long. Its needles really are soft to the touch, and it’s hard to resist giving it a pat every now and then.

Dwarf White Pine ‘Soft Touch’ at the Manor House foundation

At the entrance to the Nature Center, we use another dwarf evergreen as a container plant. Dwarf Alberta Spruce (Picea glauca ‘Conica’) also was developed from a very large native tree, the White Spruce. This dwarf variety is very slow-growing and maintains its classic Christmas tree shape without pruning. It can live for years in containers, but should eventually be given some space in the landscape. It can become a 10-13 foot tree in time, so we will have to turn ours loose on the grounds in a few more years.

Consider adding winter’s native greens to your landscape

This blog is authored weekly by Cathy Ludden, conservationist and native plant educator; and Board Member, Greenburgh Nature Center. Follow Cathy on Instagram for more photos and gardening tips @cathyludden.

Deck the Halls…and Gardens

Every landscape needs “winter interest,” and several of our favorite native shrubs are real show-offs this time of year. 

Without a doubt, the star of the season is Winterberry (Ilex verticillata). Winterberry is a holly, but unlike most hollies, it is deciduous – meaning it loses its leaves in the fall. And that’s a good thing! The berries start turning red in October while the leaves are still green. Weeks later, the leaves drop off revealing brilliant clusters of berries that remain all winter. 

Winterberry in late October
Winterberry in mid-December

Or, at least, the berries could remain all winter unless the local birds have other ideas. We assumed for a long time that the berries needed all winter to ripen, because neither rain nor snow nor dark of night caused them to disappear until robins returned in the spring. 

Winterberry after a February ice storm

But in some years, mockingbirds, blue jays, and cardinals seem to celebrate the holidays with Winterberry snacks. So, we can’t totally promise the berries will remain all winter. But the robins definitely will finish up whatever is left in the spring.

If you have a boggy area on your property, Winterberry is a great choice – it will live in standing water and will happily send out shoots to form a thicket. So, it’s a great choice for a rain garden or a problem wet area. It does well in average garden soil as well, with full sun and regular moisture, and can be controlled easily by removing new shoots. 

Like other hollies, Winterberry is dioecious, meaning both male and female plants are necessary for berry production. Bees visit the flowers on the male plant and carry the pollen to the flowers on the female plants to fertilize the ova and produce berries. Your local nursery will sell you a male shrub to plant somewhere near the female so bees can find both plants when they bloom in the spring. The flowers are small and white and not very noticeable, but the shrub is a lovely deep green all summer long.

Winterberry can grow 8 to 12 feet tall, but can be pruned for shape and size. There are cultivars that naturally stay much smaller – ‘Red Sprite’ takes a rounded shape and stays 3 to 4 feet tall. You’ll need ‘Jim Dandy,’ the male pollinating plant, to get berries on ‘Red Sprite.’  We suggest avoiding the recently-introduced Asian hybrids of Winterberry. The value of their berries for native birds and the risk of them becoming invasive are unknown.

Full-sized Winterberry in front of the Manor House at the Nature Center
‘Red Sprite’ is a compact form of the native shrub

This time of year, you may find whole branches of Winterberry mysteriously disappearing when it’s time to decorate for the holidays. The Garden Club of Irvington recently collected Winterberry and other foraged materials from our grounds to decorate the Nature Center. The impact of Winterberry on our fireplace mantles is spectacular! (Word of caution: the berries can be toxic to dogs, cats, and toddlers, so it’s best to keep them out of reach.)

A member of the Garden Club of Irvington decorates the Manor House mantel 
Deck the halls with boughs of Winterberry

Winter solstice is nigh, and the Winterberry is bright!

This blog is authored weekly by Cathy Ludden, local expert and advocate for native plants; and Board Member, Greenburgh Nature Center. Follow Cathy on Instagram for more photos and gardening tips @cathyludden.