Boxwood plants – as hedges or clipped specimens – are a classic. They bring a look of calm, organization and structure to any garden space, and with older homes they give just the right ‘period’ look, while they can look modern and minimalist too, in the right setting. They have been used for centuries in this way, even the ancient Romans grew them, and they are widely seen in Europe. The early settlers shipped plants over for their gardens, to be created in the European style, but in some regions they were disappointed. Yes, where the climate is mild, without cold winters or hot, humid or dry summers, these plants thrive and look great. But in tougher areas it is a struggle to keep them alive and healthy. Diseases and pests take their toll, and require lots of attention, and they are becoming more severe and challenging.
American breeders have done a lot to make boxwood more suitable for colder areas, and Japanese boxwood often grows better, and has been used for hybrids too. But aren’t there alternatives that give that ‘look’ – tight, dense structure, tiny green leaves – but work better, with less attention needed, and fewer pests? The answer is, “Yes, there are, although often they are overlooked or not known about.” Let’s fix that and take a closer look at some useful alternatives to boxwood, that will give you the same look, but be much less trouble to grow.
Turn to the Hollies
Say ‘Holly’ to the average person and they see a spiky green leaf with red berries, a classic Christmas image, bordering on cliché. Gardeners might see a dense hedge or tall clipped plant, with deep green leaves, or perhaps with green and cream variegated foliage – but in their mind’s eye they probably won’t see a plant that looks like boxwood.
The holly plants – called Ilex by botanists – are a big group, with species growing from cold zones into the tropics, and in many sizes and shapes. Among them are some plants with small evergreen leaves, and with few or no spines. In the hands of plant breeders, selections have been made from unusual seedlings with even smaller leaves and more compact growth, so that plant you saw and registered in your mind as ‘boxwood’ could easily not have been it at all, but rather a holly bush. Let’s look at some of the possibilities, and discover that having low green hedges, and trimmed balls of green in the garden or in pots, can be easy, and give you the look without the work.
That red berry/spiny leaves image of holly belongs to the European Holly, Ilex aquifolium, although most garden holly bushes in America are hybrids. Asia has its own holly plants, and the Japanese holly, Ilex crenata, is very different. This small tree doesn’t only grow in Japan – it can be found wild in China, eastern Russia, and Korea, if you care to look for it, but it was in Japan that it was first ‘improved’. Japanese gardeners also love small leaves and neat, compact plants, although they are more likely to clip them into Niwaki (庭木), trees tightly clipped into twisted specimens, or mass plantings clipped to undulate or flow, like water or clouds. They use various plants for this, including small-leaf azaleas, but Japanese holly is one of the most popular, and over the centuries smaller trees, with tiny leaves, were selected. One form, called by the frankly uninspiring name of ‘Convexa’, was brought to both Europe and America exactly a century ago, but it didn’t attract much attention, and languished in the corners of specialty nurseries.
Only recently, as boxwood diseases became more serious problems, and with a revival of more formal garden planting, has the Convexa Japanese Holly become popular. When you see it, your whole idea of ‘holly’ will be challenged. The tiny, leathery leaves are dark green, and look like the healthiest boxwood you have ever seen. They do have a slightly convex shape – the edges curve down, making the leaf an upside-down bowl shape, but this is not very noticeable. There are no spines, and the leaf edges are smooth. Although it can grow as much as 6 or 8 feet tall and across, it has a dense, twiggy structure, so it can equally be kept just a foot or two tall – perfect for low hedges and small domes, pyramids and cones. Equally, if you want taller hedges and bushes, that works too, and guess what? Convexa Japanese Holly grows as much as a foot a year, so taller hedges take just a few years to create, while boxwood can take a very long time to become more than a low edging.
Convinced? Well consider this – Japanese holly grows really well in warmer areas, right into zone 9, where boxwood often suffers. It enjoys heat and humidity and grows anywhere from full sun to light full shade – that is, beneath trees, but not planted deep under low and heavy evergreens. It is drought resistant, and it even tolerates salt spray, so if you want the ‘boxwood look’ at your beach house – something impossible before – you can do it with ‘Convexa’ or other similar varieties.
Small leaves are not found just in Japanese holly. There is an American native holly – one of several native species – that also has smaller leaves. The Yaupon Holly grows along the south-east coast, from the Carolinas south into Florida, and around the Gulf into Texas. The best form for a boxwood substitute is called ‘Nana’, also known as ‘Schillings’, and a similar variety is ‘Stoke’s Dwarf’. These are smaller forms of the larger wild plant, Ilex vomitoria (yes, that really is the name, because a tea made from the leaves is an emetic – it makes you throw up – and it was used by native Americas as a purgative).
The leaves of the Dwarf Yaupon Holly are between ½ to 1½ inches long, with a glossy surface. In spring they are a bright yellow-green, and they mature to a rich deep green for the summer, fall and winter. If you look closely you will see a very fine serration along the edge, but without close inspection it does look just like boxwood. The twig structure is dense, and it clips easily into anything you want it to be. Left alone is forms a natural mound that is also attractive and neat – perfect for lower maintenance.
If you already guessed that the Dwarf Yaupon Holly is resistant to salt, you are right, even more than the Japanese holly is. It will grow right at the shore, even in dunes, and it is incredibly drought resistant, once established. It is only hardy into zone 7 and does best in zones 8 and 9 – exactly where boxwood struggles.
You can see that if you live in warmer parts of the country there really is no need to struggle with boxwood plants. Look instead to the Japanese holly or Yaupon holly for great substitutes that look just as good, and are much, much easier to grow.