Great big hedge plants

Position available: We are looking for a team of tall (15'), dense (by virtue of evergreen leaves or foliage bolstered by extreme twigginess), low-care shrubs. Applicants must have potential for rapid expansion, be willing to grow in a wide variety of situations, tolerate repeated clipping, and maintain a neat appearance even under stress. Flowers desirable but not required. Apply at west lot line, please turn with your best side facing our home, not the neighbor's.

 

Of course we joke, but with a basic seriousness. Hedge plants meant to provide privacy should be at least 8' tall and often must be 15' tall to screen second story windows. Although evergreen foliage is an asset it's not requisite. Many hedges screen outdoor activities in places that are not frequented in winter, so deciduous plants of dense character serve as well and often fill out more quickly.

Before you invest the dollars and digging to make a hedge, take a look at possibilities by visiting an arboretum or botanical garden that maintains a hedge collection, such as this one at the Morton Arboretum in Lisle, IL.

Before you invest the dollars and digging to make a hedge, take a look at possibilities by visiting an arboretum or botanical garden that maintains a hedge collection, such as this one at the Morton Arboretum in Lisle, IL.

A great hedge is able to sprout new growth from cuts into bare wood and maintains this ability even into old age. All but one of our picks meets this criteria. Ironically, that exception is probably the first plant most people think of when planning a hedge. Since its other qualities are stellar, we include the arborvitae!

 Here is our 12-species short list in answer to that big hedge opening.

 About sunlight and shade: Of these, most perform best in full sun and only tolerate the shade. If the space you're hedging is not receiving at least 6 hours of direct sun per day, yews and leatherleaf viburnum are your best bet but expect even those to grow more slowly than indicated, and be less dense than otherwise.

European beech (Fagus sylvatica) Fast growth, 12-18" per year on young wood. Deciduous but tends to hold its foliage through winter on branches not yet able to flower and fruit (beechnuts). Regular pruning promotes the growth of new wood. If grown unchecked this is a tree to 100' but can be kept much shorter with pruning every two years. Prune hard annually during dormant season with high summer touch-up for the most crisp edge or shape.

European beech trees planted close and clipped regularly once they reach the desired height -- a great, long-lived hedge. The leaves on new wood hang on until spring so the hedge still works as a screen in winter.

European beech hedge at Massachusetts Horticultural Society's Gardens at Elm Bank in Wellesley, MA, recently planted

and ten years later. It's become dense through regular pruning. That has promoted lots of twiggy new growth, and that many more leaves retained through winter.

Beech is quite tolerant of shade but that doesn't mean it will be as dense in shade as in sun. Why is this section thinner? Look up -- trees overhead reduce the hours of light that reach the plants below.

You'll see trees as a hedge, for maximum longevity and height. This beech hedge at Edinburgh Royal Botanic Garden is over 100 years old

You'll see trees as a hedge, for maximum longevity and height. This beech hedge at Edinburgh Royal Botanic Garden is over 100 years old

The trees in the hedge are planted about 3' apart and have been kept to 1/4 size -- 20 feet tall.

The trees in the hedge are planted about 3' apart and have been kept to 1/4 size -- 20 feet tall.

The hedge is about 6' wide at its base, tapering to 3' at the top.

The hedge is about 6' wide at its base, tapering to 3' at the top.

European hornbeam (Carpinus betulus) A 35' deciduous tree that often holds its leaves through winter, especially if frequently pruned. There is a narrow form ('Fastigiata') that may make pruning for width simpler, but hang onto your ladder because it still grows to 35' high unless curtailed. A dwarf, narrow form ('Columnaris Nana') can do without any pruning since it tops out at about 8' but arrives at that height far more slowly.

Even in winter it's a good screen since leaves persist until spring on young branches, and the branches themselves are close set.

Even in winter it's a good screen since leaves persist until spring on young branches, and the branches themselves are close set.

Hybrid yew (Taxus x media, especially 'Hicksii'). A dense, needled evergreen. Yews are probably the most shade tolerant species on this list. Faster to grow than people expect, at about 12" a year if it receives half-day sun or more. The columnar Hicks yew can grow to 20' tall and 6-7' wide but accepts regular shearing with great grace. Thus a row of Hicks yews can become quite a narrow tall hedge. Two important notes: 1) It is totally intolerant of poor drainage. 2) Yews are a favorite food of deer.

You may wonder why yews are on our Big Hedge list if you know them only as the shrubs in a foundation planting that must be clipped regularly to be kept below the windows. Here are two of those foundation yews showing their true nature; they are probably the common varieties 'Densiformis' and 'Brownii.'

No matter which plant you are considering for a hedge, beware the garden center plant tag or catalog listing as an authority on potential size. For instance, Ward's yew (Taxus x media 'Wardii') plant tags usually describe the plant as 3' tall. Plant encyclopedias are more honest, reflecting the size you see here, 6-8' tall, with a 12' wide spreading form.

What appear to be green-brown walls here at Sissinghurst Castle in England are yew hedges.

What appear to be green-brown walls here at Sissinghurst Castle in England are yew hedges.

Yews are very tolerant of pruning but like all plants will become top heavy, with "bare ankles," unless clipped to be wider at the base than at the top. At close range these yew balls are see-through in the bottom 1/3.

Yews are very tolerant of pruning but like all plants will become top heavy, with "bare ankles," unless clipped to be wider at the base than at the top. At close range these yew balls are see-through in the bottom 1/3.

Leatherleaf viburnum (V. x rhytidophylloides). 12 to 15' tall and somewhat less wide. Large, leathery, felt-backed leaves hang on through all but the worst winters. Fast growing. Hard to tame through pruning so best grown as an informal (no-prune) hedge. The second most shade tolerant plant on this list after the yew. Creamy white flat-topped flower clusters in spring; there is sometimes some fall bloom as well. The flowers have a rank odor but thankfully it's a scent that does not carry. Red berries ripen to black and attract songbirds. 'Alleghany' and 'Willowwood' have especially clean, durable foliage.

Leatherleaf viburnum, clipped regularly to keep it half-height. This viburnum's leaves remain green year-round in all but the most severe winters. When it's very cold, the leaves fold down.

Leatherleaf viburnum, clipped regularly to keep it half-height. This viburnum's leaves remain green year-round in all but the most severe winters. When it's very cold, the leaves fold down.

There are many fine viburnums and most could be a good Big Hedge, as you see here. However, most are not so tolerant of shade or as effective a screen in winter as leatherleaf. For a quick reference for selecting among these shrubs, download our Viburnum chart.

Arborvitae (Thuja occidentalis varieties). Also called cedar and eastern white cedar. The classic hedge species, touted as a wonder plant and consequently disappointing because it's been put into a bad situation. Requires at least half sun to grow well. Unlike all the other plants on this list, including the yew, it will not grow back from leafless wood so it cannot be let go then pruned back. It must be pruned regularly to be kept smaller than it can be and also maintain its density. The species grows to 50' but there are many columnar dwarfs available, ranging in potential from 8' to 30' and varying as much in width. (30' 'Nigra', 20' 'Wintergreen', 15' Techny' and 'Emerald'.) Growth rate varies, too, with the largest varieties growing most quickly, up to 12" per year.

 

Arborvitaes are often a gardener's first and only thought when planning a hedge. They deserve a prominent place on a candidate list but there are easier plants to hedge if the situation does not absolutely require evergreens.

Something had to be done after this arb hedge was allowed to creep in size until it rattled in the utility lines and crowded out the garden. The options: start over or prune. Either way it would be years before we would again have a full hedge. We pruned 3' off the trees' tops and also narrowed them by that amount. Arborvitaes cannot sprout from leafless wood so this left gaps. Remaining foliage did eventually grow into the voids.

Old fashioned snowmound spirea (Spiraea x vanhouttei) All spireas make a nice hedge but only Vanhouttei goes to 8' (sometimes 10') and is so dense that you can't see through it even in winter. Sadly, it's tough to find this fine plant since the rise in popularity of dwarf summer blooming species and the (much smaller and less graceful) dwarf snowmound (S. nipponica). However, Vanhoutte is out there at some nurseries and is well worth the hunt. Quite shade tolerant, if you can accept reduced growth rate, size and bloom. Bears white flowers in May. Prune it after bloom each spring and then remove some old wood completely (to the ground) or give the shrub room to be an 8' x 8' mound and simply remove some old wood each year. An interesting "plus": Rarely needs fertilization because so many birds find shelter there and leave their droppings.

Old fashioned snowmound spirea, Spiraea x vanhouttei.

Old fashioned snowmound spirea, Spiraea x vanhouttei.

Privet (Ligustrum species and hybrids) Perhaps best known today as the gold leaf hybrid 'Golden Vicary'. However, those in zone 5 or 4 should not go for the gold but stick with common privet, Amur privet or border privet (L. vulgare, L. amurense or L. obtusifolium). 15' tall and a bit wider than tall if allowed its head. Very fast growth. Willing to be pruned into almost any size or shape. (As for all hedges, just make sure the base is wider than the top or the plants' lower level will thin out). Privet has the reputation of growing "anywhere" but don't believe it -- in the shade it's a pitiful shadow of what it can be. Privet does bloom if minimally pruned. Some people find the flowers' scent offensive, akin to hyacinth gone bad.

Privet deserves its place high on hedge-able plant lists. It's fast, tough and adaptable. Because it can grow several feet each year it's easiest to tend a privet hedge with one very hard cut in late winter and one touch-up in late summer. That, or just let it grow!

Compare this privet hedge to the hedge on the right to see the benefit of keeping the ground clear under the shrubs' full width. The lowest branches can grow and the hedge can remain dense even to the ground.

Ninebark (Physocarpus opulifolius varieties). A native shrub 10' tall and wide that's enjoying great popularity in its purple leaf forms ('Diablo', 'Lady in Red', etc.). Unfortunately it's also being misrepresented as 4-, 5 or 6' tall. It's better to assume that every one will aspire to the species full 10' potential. For those duped into planting ninebark in smaller space, transplant that shrub, split it while you have it out of the ground, and use the pieces to create a 10' x 10' informal hedge. Few shrubs are so easy to grow. Does not tolerate shade except light shade (unless you can tolerate a scraggly plant!) and is very difficult to control with shears. Early summer flowers are small white lacecaps that age to pink seed pods.

Ninebark 'Diablo' is 7' tall even here where large trees shade it for most of the  day.

Ninebark 'Diablo' is 7' tall even here where large trees shade it for most of the day.

Ninebark blooms in early June and if it is not pruned afterward, will wear pink seed pods in July.

Ninebark blooms in early June and if it is not pruned afterward, will wear pink seed pods in July.

If you do not need complete privacy in winter, a deciduous hedge can be a better choice. Most deciduous plants grow more quickly than evergreens of comparable mature size.

If you do not need complete privacy in winter, a deciduous hedge can be a better choice. Most deciduous plants grow more quickly than evergreens of comparable mature size.

Beautybush (Kolkwitzia amabilis) Big (20'), fast, as rowdy as you'd expect a honeysuckle cousin to be, loaded with fragrant pink flowers and butterflies every June, and surprisingly vigorous even in shade. This is the plant on our list you may have to see to understand its value. Many people ask us about them every year, "There's this crabapple tree or something, it's loaded with flowers when nothing else is blooming..." Grow it as an informal hedge -- no pruning except to take out some old wood every year. Shear it and it will sprout every which way but what you expected.

The beauty bush featured in What's Coming Up 45 was taken to be a tree by our reader. That's because it had been pruned to remove most of the low, wide canes. Imagine this full to the ground -- that's a sunny Kolkwitzia hedge. Shaped as you see here, that's the plant's form in more shade.

Burning bush (Euonymus alatus). One of the most shearing-tolerant species around, but its real value is as a 15' tall informal (no-prune) hedge. Realize that dream by giving it room to spread as wide as it is tall, then just hang up your pruning tools and enjoy the privacy. Tolerant of shade but expect less growth with less sun, and diminished or non-existent fall color. Two notes: 1) This is not the dwarf form 'Compacta', which tops out at about 10'. 2) Please check at local garden centers before setting your heart on this one, as the species has been banned from sale in some States for its seed-sown invasiveness.

Prune a burning bush...

Prune a burning bush...

...or just let it grow. Either way burning bush makes a fine hedge.

...or just let it grow. Either way burning bush makes a fine hedge.

Forsythia (F. x media, varieties such as 'Northern Sun' that were selected for better flower bud hardiness). Few shrubs grow as quickly and are so dense as forsythia. It's a shame that they are so routinely hacked beyond all semblance of beauty by gardeners in pursuit of a squared-off hedge. Do yourself a favor and plant forsythia only where you can allow its full 10' height and width. Leave it alone, except to cut out about 1/4 of the canes at ground level each year and it will form a mound that blooms to its tips every year. Tolerant of some shade but don't expect uniform height or bloom from a forsythia hedge that receives different amounts of sun along its length.

For the healthiest hedge and easiest care, create a lawn-free, weed-free bed as wide as the hedge. Removing the lawn below its branches would improve this forsythia hedge. The shrubs would branch to the ground, covering that soil. It's a move that would also delight the mowing crew.

For the healthiest hedge and easiest care, create a lawn-free, weed-free bed as wide as the hedge. Removing the lawn below its branches would improve this forsythia hedge. The shrubs would branch to the ground, covering that soil. It's a move that would also delight the mowing crew.

Peashrub (Caragana arborescens). Bright green foliage, fast growth, great performance in dry, hot or windy spots and in severe cold. 15-20' tall and wide, easily pruned to any size with one firm cut per year. Yellow flowers in spring often lost in the emerging foliage. once a hedging staple, it's now hard to find except in its weeping form (sold as a small tree). Worth looking for the species or the upright, narrower form 'Sutherland.'

Peashrub is not a plant that makes anyone say "Oh wow." It's simply there. A reliable, fast, big, thick, green screen.

Peashrub is not a plant that makes anyone say "Oh wow." It's simply there. A reliable, fast, big, thick, green screen.

Peashrub is not evergreen although its branching is dense enough that the hedge has a winter presence.

Peashrub is not evergreen although its branching is dense enough that the hedge has a winter presence.

There are flowers on peashrub, but you may miss them for being yellow just when the spring foliage is brightest green.

There are flowers on peashrub, but you may miss them for being yellow just when the spring foliage is brightest green.

There are many more plants that make a fine large hedge:
We are pleased with a river birch hedge we planted on Cape Cod.
Chicago Botanic Garden's Heritage Garden is surrounded by a fine 25' bald cypress hedge.
Olbrich Botanical Garden in Madison, Wisconsin has a lush cornelian cherry hedge.
We've admired red leaf Japanese maple as a clipped hedge.
Janet's been bowled over by the scent from a mock orange hedge
We've marveled over sheared pine in an arboretum hedge demo area.
We love the walls of hemlock, rhododendron, mountain laurel and holly in Massachusetts.
So we will consider hedging almost anything, deciding yes or no by asking, "Will it be big enough, fast enough? Will it then be controllable without extraordinary pruning? How long can we expect it remain healthy and to serve our purposes, and is that long enough for this landscape situation?"

Panicum Tall ornamental grasses can serve as a hedge. They grow quickly and are absent for just two months each year between annual cut-down and regaining their full height. If they could only meet our 8' minimum and had some shade tolerance we would consider them for this Big Hedge summary.

Panicum Tall ornamental grasses can serve as a hedge. They grow quickly and are absent for just two months each year between annual cut-down and regaining their full height. If they could only meet our 8' minimum and had some shade tolerance we would consider them for this Big Hedge summary.

Not only can trees be hedged, they can be pruned as these linden trees have to become a hedge on stilts.

Not only can trees be hedged, they can be pruned as these linden trees have to become a hedge on stilts.

An oak hedge demonstrates its longevity.

An oak hedge demonstrates its longevity.