How big do Boxwoods get?


boxwood

It is an evergreen variety of tree found in Asia, Africa, Europe, South America, Central America, Caribbean Islands. It develops very dense foliage and is very suitable for the hedges. They are also popular as ornamental plants. The Boxwood is very famous for its dense wood. The wood lends itself to carve decorative pieces, chess pieces, dagger handles, spoons etc.  It does not chip or split easily. It goes in the manufacture of several musical instruments too. Boxwood trees do not bear any flowers.

It has been around for more than 4000 years and looks strong to go a few thousand years more.

What size can boxwood grow? The Boxwood may grow to a height anywhere from one foot to twenty-five feet. It all depends on the variety of Boxwood.

eThe Boxwood belongs to a vast family of trees that consists of about 90 varieties. The horticulturists have added another 350 types of cultivar to the main species. However, most of the existing Boxwood belong to the three main varieties, ie. American, Japanese and the Korean Boxwood.

The Boxwood tree comes in the weeping, rounded and columnar style. It is one of those few trees that grow in all three styles.

The Boxwood plant grows to different heights depending upon the varieties. With so many varieties, the height varies from one foot to about thirty feet. But the most common range of the height is from two to six feet.

The American Boxwood (Buxus sempervirens), which is the most popular in the USA, grows to a height of 15 -20 feet. Incidentally, the shortest Boxwood is the ‘Compacta’ variety of the Japanese Boxwood. It reaches a maximum height of 12 inches. Compacta is very appropriate to develop Bonsai forms of the Boxwood. It attains the full maturity height in 15 years!

american boxwood

The “Fastigiata” Boxwood grows to a height of 6 feet and is just 2 feet wide. Whereas, the Green mountain is 5 feet tall and 3 feet wide. The “Green velvet” is a moderate-sized plant that grows to a height of 3 ft and width of 4 ft. Wedding Ring grows just to about 1 foot tall and three feet wide.

These varieties and their sizes should give you an indication of how the height varies with the type. So before you get a Boxwood, based on its utilisation, try to decide what height and width are required. Then check with suitable varieties and get the most suitable one. Boxwood is available in a large variety of height and width to suit almost every requirement.

How long does it take for Boxwoods to grow?

They are a slow-growing tree, generally, adding less than a foot per year to its height.

Boxwood grows very dense. It develops a very thick foliage. Such densely growing trees generally have a slow growth rate. The wood also gets its density because of gradual consolidation.

Boxwood also has a very slow growth rate of fewer than twelve inches in a year. The exact growth rate is dependent on the variety or the cultivar. Most of the varieties grow between 3 inches to 6 inches in a year.

So if you are planning a hedge with Boxwood, that may take around four years to reach the desired height. But be rest assured you will get a tightly packed and almost impregnable fence.

There are a few exceptions to this standard of growth rate in the family of Boxwood. For example, Buxus Sempervirens also known as the ‘Highlander’, grows about 24 inches in a year(that is almost twice of the average growth rate)

Since it is a slow-growing tree, it is very convenient to shape it the way you want, before it gets wild and unruly. That is the reason why Boxwood is suitable for “topiary”.  Cutting, pruning and shaping the tree foliage to make various decorative shapes is known as topiary.

You can also plan to make a topiary in your garden using the Boxwood. Once shaped, it retains the shape for a couple of months, because of the slow growth.          

Where do Boxwoods grow best? 

Boxwood is quite hardy and manages well in various types of soils and climatic conditions. It is suitable to grow between zone 5 and 8.

It grows well in sunny as well as cold weather. However, the heavy wind does not go well with the Boxwood. Though all Boxwoods do well in a hot and cold climate, individual varieties may have their own preferences.

For example, the Littleleaf Boxwood (Buxus microphylla) with all its cultivars thrive well in sunny climate rather than cold. But on the other hand, the Common Boxwood with its cultivars grows better in colder climates.

littleleaf boxwood

Before you select a Boxwood, check its suitability for ‘your’ zone. Some do well towards zone 5 while others are good towards zone 8. Eventually, all of them are within zone 5 and zone 8.

During the summers, it would do well to protect the Boxwood from extreme heat in the afternoon by some shade. It also needs protection from severe winter winds. These winds cause ‘Winter Bronzing’ (loss of moisture from the leaves causes it to turn brown).

Ensure that the Boxwood gets at least 4 hours of good sunlight. If it is possible, the northern side of the building is the best place to plant a Boxwood. Else, the eastern and westerns sides are the next best choice. Refrain from planting it to the southern side of the building, as the requisite sunshine is not possible there.

Boxwood grows well in any type of soil. A little acidic to neutral soil, pH ranging from 6.5 to7 would be the best. If the soil is very acidic (pH less than 6.5) treat the soil with agricultural lime to reduce the acidity. Conversely, for the alkaline soil(pH ranging higher than 7), the treatment of the earth with sulphur will reduce alkalinity. The most important criteria for the ground is its water drainage capability. Boxwood cannot stand wet roots. It will develop root rot very fast, and that can be fatal for the tree. Waterlogging at the tree site or nearby is highly undesirable.  If you plan to plant a Boxwood at a particular place, check the water drainage of the soil by a straightforward and practical technique.

Dig a one-foot diameter and one-foot deep hole at the designated place. Fill it with water up to the brim. Next day again fill the hole up to the brim with water. Check the water level every hour. It should reduce by at least one inch in one hour. Which means in the next 12 hours, the hole should have drained all the water. If that happens, it is a sure sign of excellent water drainage capability of the soil. If the soil fails the water drainage test, check some other place. All those places where the water puddle forms during the rains are unsuitable for the Boxwood.

The texture of the soil should be light and a bit fluffy. If it feels heavy, add organic matter to the soil to lighten it. Light and well-drained soil are ideal for the growth of the Boxwood.

What is the best time to plant Boxwoods? 

The best time to plant the Boxwood tree is during the fall (September, October and November).

The Boxwood should be planted at such a time, which will be most conducive to the roots. If the roots establish themselves well in the soil, the tree will automatically flourish in good time. During the fall, it is neither too hot nor too cold, and the soil condition favours the root development. Before the advent of severe winter, the roots will get sufficient time to stabilise, and the tree will flourish well.

Avoid planting the Boxwood during peak summer and peak winter. If for some reason, you missed planting the tree in the fall, then try to do it in the early summers. The Boxwood tree is drought sensitive. Hence, before planting the tree, check the soil for moisture if it feels dry, water it well. And then plant the tree. Check the humidity of the ground every alternate day.  If needed, water it whenever the soil feels dry.

Winters are very unfavourable to plant trees. The climatic conditions are very harsh for a new plant to survive. The ground also hardens up. The roots will find it very difficult to penetrate the earth to find a foothold.

How far apart should you plant Boxwoods?

The most appropriate distance would be equal to half the width of the planted Boxwood tree.

boxwood spacing

The Boxwood tree has very dense foliage, and hence we should not plant them closer than half the width of the plant. That will result in very severe overlaps, and it may cause damage to the plants. Very tight foliage restricts the sunlight and airflow, and gives rise to fungal infection.

With the above stated distance, once the plants grow up to the right size, constant pruning and trimming of the overlapped section are necessary to keep it optimally dense.

The Wintergreen has a width of 3 -5 feet. Assuming the average width to be 4 feet, the distance between the two plants should be about 2 feet. Do not reduce the distance less than 2 feet

But if we use Green beauty, the gap between the two plants should be 2 ½ feet minimum. That is because the average width of the plant itself is 5 feet.

For decorative purposes like topiary, you can place the plant at any suitable place, where it would look beautiful. 

How often do you need to water Boxwoods?

Watering once in a week is sufficient. Watering should always be deep, meaning you should put plenty of water at one time to allow the water to go down deep in the soil.

It will happen if you keep the flow of water slowly and allow the water to seep into the soil gradually. Deep watering makes the root go deep and establish a firm grip on the soil. It helps keep the Boxwood stable and firmly rooted. If the roots are shallow, it will be easily affected by hot or cold weather.

But remember waterlogging should not happen or the roots will rot.

The frequency of watering will also depend on the climatic conditions. During the hot summer, watering may be required three times in a fortnight or more.

The judgement comes from checking the moisture of the soil. If the soil is dry, water it, even if you have watered it just a few days back. Remember that Boxwood is not drought resistant. It can neither withstand lack of water nor excess of it. It needs just the right amount of water.

After you plant a Boxwood, for about a year, it will require watering twice in a week, and then you can reduce it to once in a week.   

How often do you have to trim Boxwoods?

Boxwood requires pruning, shearing and cutting very frequently, as it grows dense quickly. The vertical growth of Boxwood is slow, but the foliage growth is robust.

The Boxwood is planted mainly for hedges and topiary. Very rarely it is used as a standalone tree. And even in that case, it is a part of the landscape.

Do not plant the Boxwood if you do not like pruning, and trimming. You will have to inspect your topiary and the hedges once in seven to ten days to locate dead, damaged branches. Some foliage will need to be cut to allow the movement of air inside the bush. Sunlight should penetrate inside the growth to prevent fatal fungus attack.

Shearing the Boxwood is ubiquitous to encourage dense foliage growth. But once the foliage becomes thick, it needs excellent care. Apart from the point of hygiene and health, pruning is also required to shape the Boxwood for aesthetic reasons.

One has to do the cutting, shearing, pruning and plucking with the Boxwood. It demands excellent grooming care. For the newly planted Boxwood, do the first pruning after a year.

Why are the leaves on my Boxwood turning yellow?

Boxwood leaves, turning yellow is not a good sign. It is indicative of some disease of the tree.

boxwood leaf yellow

One of the prominent reasons for the Boxwood leaves to turn yellow is the root rot. Stagnant water at the root promotes the growth of the fungi Phytophthora spp and Ganoderma lucidum, which rot away the roots. The symptoms of root rot are slow growth, and the foliage looks dull. The leaves turn yellow and then brown and ultimately drop off. Unfortunately, there is no effective cure for this condition. Only the precautionary measures can save Boxwood from this disease. At any cost, ensure that the soil is drained appropriately. Otherwise, it can be fatal for the plant.

Another reason is Canker. It is again a fungal infection of Boxwood. At times the foliage becomes so dense, that sunlight and fresh air cannot reach the internal part of the tree. The staleness results in the growth of fungus pseudonectria rovselliana, which develops salmon coloured fruiting on the branches. The leaves turn red and turn yellow before falling off.  Canker is a severe disease of Boxwood.

Spraying of some fungicides may reduce and rectify the problem. But the best way to handle this is to keep trimming the internal branches and the outer foliage just enough to allow free air circulation and sunlight to reach all parts of the Boxwood.

Boxwood Blight is another dreadful disease of the Boxwood trees. The fungus Calonectria pseudonaviculata is responsible for this disease. They afflict the underside of the leaves, and in due course of time, the leaves turn brown before withering off.

Never ignore the yellowing and browning of the leaves. If detected in the earlier stage, some fungicides may recover the plant. The foliage is dense. Hence the spread of the disease is swift, and it could turn fatal if not controlled in time.

How do you keep Boxwoods healthy?  

Ensure that the Boxwood is planted and watered, as suggested earlier. Proper pruning and keeping the tree clean is also essential.

boxwood pruning

The following suggestion will also aid the good health of the Boxwood;

  • Protect the Boxwood plants from full sun in the winter season. The sun and the cold winds dehydrate the leaves very fast and turn it brown. If possible, plant in such a location where the sun does not shine over the tree directly. Or you can also put up some shade.
  • Boxwood needs protection for chilly wind. It cannot stand the frigid wind for long.
  • The roots also need protection from the extreme cold. One effective way to do this is to apply mulch to the ground above the roots. Mulch is a mixture of organic substances like the grass, sawdust, wood chips, bits of leaves, barks etc. It has insulative properties, and the cold is not able to penetrate down to the roots. Moisture retention property of the mulch is also excellent, and it delays the drying up of soil during the hot summers. Remember to extend the mulch all under the tree and at least 12 inches beyond the circle of the foliage. Occasionally check the mulch for any rot or infections. The mulch also keeps the soil cool in extreme summer. To sum it up, the mulch is an excellent protection for the roots from extreme cold and scorching conditions.
  • The American and the Little leaf varieties of Boxwood have shallow roots. Do not plant these trees deep in the ground. It creates a lot of stress for the plant and at times, kills the plant. The roots should go a little less deep in the ground as compared to its position in the container.

Adequate watering and proper air circulation keep the Boxwood healthy, and it does not demand any special nutritive care. But some experts believe that a standard mixture of 10/10/10 fertilizer when used for the Boxwood, in spring and fall, will help it remain healthy and improve its immunity. 10/10/10 indicates that the fertilizer should have 10% each of nitrogen, phosphorus and potassium. These three are the essential fertilizer components helpful in all-round growth and development of any plant, including the Boxwood.

Do Boxwoods attract bugs?

The Boxwood does not attract stink bugs. But some other pests are known to invade the Boxwoods.

The following are the three pests/insects which are known to attack and spoil the Boxwood plants

Boxwood Leafminer

Though these insects originally were found only in Europe, but of late they have been troubling Boxwoods in the USA also. Once adult Leafminers land on the Boxwood, they lay eggs on the leaves. The hatched larvae and the adults voraciously eat into the leaves and keep laying eggs to propagate. These pests are orange-yellow to red in colour.

You can try some insecticides containing bifenthrin, carbaryl, cyfluthrin or malathion to control Leafminer. These are known to be quite effective. However, prune off the parts of the trees which have been infected by Leafminer. It will control the spread of the disease.

Box mites

They can be found sticking to the underside of the leaf and can be seen as tiny yellow, white spots. The mites also eradicate the leaves if not controlled. The insecticides suggested for the Leafminer are effective for the box mites also. Dilute mixture of the insecticide with water, in the recommended proportion, should be sprayed liberally on the plant.

Box psyllids

The symptom of attack by this pest, is the cupping of the leaves. It lays eggs on the leaves, and when the larvae come out, it starts feeding on the leaves. Somehow because of all this, the leaves start curling to form closed cups. Inside the insect devours the leaves thoroughly.

Bifenthrin, malathion or cyfluthrin based insecticides are known to work well on these psyllids.

Frequently visit your Boxwood hedges and trees to look closely at the leaves. If any symptoms are visible spray the water-based insecticides immediately to reduce the damage and prevent the spread of the insects.

Boxwoods are amazing trees to have around. They add grace and beauty to the house and the property in general. They are deer resistant too which offer protection for your house. It does demand some care, but all that is worth when the trees grow up and become a part of the beautiful landscape. 

Lindsey Glenn

I've been learning about gardening since 2015, helping friends and family to grow their trees. I am passionate about trees and love sharing everything I learn about them.

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