Euonymus is a genus of flowering shrubs with recognized species and very many common names. Most of the species are native to Eastern Asia, but this plant commonly grows also in many parts of Europe, America, Africa, and Australia.
This perennial, which can be deciduous or evergreen, is commonly known as the spindle tree and is a popular garden plant. Many of the deciduous varieties of euonymus produce attractive berries and have brightly colored, red foliage in the fall.
Certain varieties of euonymus, such as burning bush, are listed as invasive species in parts of the USA.
History
Many euonymus species found their way to America in the mid-1800s. The shrub was introduced to Europe at around the same time.
By the end of the century, euonymus was widely promoted as a garden ornamental, and it became a very popular garden shrub, due to its vivid fall foliage.
Almost a hundred years later, it started to be reported as an invasive species. There are some climbing species, such as Euonymus fortunei, that when it climbs, adds significant weight to the branches of native trees.
This poses a threat to native species during periods of storm or excessive wind. This species can also grow as very dense ground cover, and it can take over other native ground cover species.
Plant Facts
| Scientific name | Euonymus |
| Common names | Euoonymus, spindle tree, burning bush, wintercreeper, strawberry bush, wahoo |
| Genus | Euonymus |
| Family | Celastraceae |
| Height | 10 to 20 feet (6.1 m) |
| Width | 10 to 20 feet (6.1 m) |
| USDA Plant Hardiness Zone | Zones 6 to 9 |
| Native to | Mostly Asia, some native to eastern North America |
| Blooming season | Spring |
| Flower colors | White, yellow |
| Plant specific features | Many species available, brilliant fall foliage |
How to Plant and Grow Euonymus Bushes
Once you have chosen your planting site, you need to dig a hole that is two or three times the size of the root ball. If the soil is particularly poor, you can add some fertilizer at this stage, and then make sure you water the newly planted shrub thoroughly.
Where to Plant
Evergreen varieties can grow well in either sun or shade, whereas the deciduous species prefer a sunnier location.
Species or cultivars with either yellow or white foliage should be planted where they will receive some shade and some sun. Too much sun will scorch their tender new growth, and insufficient sun will result in less vivid foliage in the fall.
Generally, euonymus is an easy plant. It will thrive in many situations and in all but the harshest of conditions. There are some varieties, such as Euonymus japonicus that will tolerate salt spray and salt deposits in the soil.
This can be a good choice of plant for a hedge or windbreak in a coastal location.
When considering where to plant euonymus, you need to be aware of its potential size at maturity. Allow the shrub to have sufficient space to grow without being crowded. This will ensure good airflow through the plant and help to prevent the onset of fungal disease.
When to Plant
As long as the ground is not frozen solid, you can plant a container-grown euonymus shrub at any time of year. However, as with many plants, it is preferable to avoid planting in the heat of the summer, or the cold of the winter months.
If choosing the Spring for planting euonymus, bear in mind that the watering requirement will be more onerous during the summer months than if you plant in the fall, when the soil is naturally going to be moister.
Euonymus Shrubs Care and Maintenance
Soil
Euonymus is a tough shrub, particularly the evergreen varieties. It will tolerate a wide range of soil types, from acidic to alkaline, but prefers well-drained, moist soil.
Ideally, the soil will also be rich and fertile, but again the euonymus will thrive whatever the quality of the soil. And you can always add a little fertilizer at the time of planting, to improve the condition of the soil.
Water
A newly planted euonymus, like any newly planted shrub, needs frequent irrigation for its first growing season. This allows it to develop a robust root network that will then enable the euonymus to absorb moisture and nutrients from deep within the ground.
Thereafter, you will find that the euonymus is a low-care shrub; watering can be infrequent, and the plant will even tolerate drought conditions. Under normal conditions, euonymus will need only infrequent irrigation.
The most efficient watering method is to soak the plant and then allow the soil to completely dry out before re-watering. This encourages deep root growth, rather than allowing the roots to spread under the soil surface.
Fertilizer
At the time of planting euonymus, an application of a slow-release, general purpose fertilizer will be beneficial. It will be especially beneficial for a Spring-planted shrub since this will help the shrub develop plenty of new, vigorous growth at the time it is growing best.
Once it is established, it isn’t necessary to feed euonymus, although if you wish, you can apply a feed in the Spring and early Summer to boost its growth.
Sunlight
Euonymus shrubs will thrive in both sun and shade. Whilst generally, they prefer a site that receives both sun and partial shade, variegated varieties do best when they are given more sun.
Larger varieties of trees too, especially deciduous specimens that produce vivid fall color, will do best if they can access more sunlight.
The best types of euonymus for a shadier site are the low-growing and ground-cover species that will tolerate shade.
Pruning and Repotting
Euonymus shrubs are moderate to slow-growing. This means that pruning is not a big job and may not be necessary at all.
If you become aware of any dead or diseased branches, then remove these as soon as you notice them. Dead or damaged wood can and should be removed at any time of year in order to keep pests and diseases at bay.
If a newly planted euonymus develops new growth, you can trim some back, in order to minimize the risk of stressing the shrub unnecessarily when it is establishing itself in its new growing position.
A variegated euonymus should be checked annually for any branches or growth that has reverted to a single green color. If some shoots have lost their variegation, these need to be cut off.
This will ensure that the shrub’s leaves retain their variegated colors. Failure to do so can lead to an all-green leaved shrub.
Propagating
More usually, propagation of euonymus is undertaken by cuttings, but it is possible to sow seeds. Seeds can be sown either in the Spring or in the early Autumn.
Cuttings can be taken during the Spring to create new plants. Cuttings will be clones of the parent plants (unlike seed-grown specimens) so this is the best choice of method if you are wishing to propagate from a hybrid-raised euonymus.
Although cuttings will root easily, they will take about two years before they are ready to be transplanted to their final planting positions.
The cuttings should be softwood or semi-ripe sections of the stem. It is important that they have not become fully woody. The cutting should be taken from a piece of stem that is in active growth.
Don’t use a stem that is damaged or diseased, and doesn’t use a flowering branch for cutting material, as this will impede the rooting process.
Remove the new leaves on the stem, just leaving the top pair on the cutting. This will help to conserve water in the plant stem whilst it is in the process of developing its new roots.
When the cutting is placed in the growing medium, you should water it well and make sure that the compost is in direct contact with the stem. Keep the cuttings in a bright, warm position out of direct sunlight.
It’s essential that the compost doesn’t dry out, so check it frequently and water the pot whenever it feels dry to the touch. In periods of very hot weather, you may need to water every day and also mist from above in order to keep the plant tissue moist.
In the right growing conditions, the cutting will root within two months and possibly within just a few weeks.
Once the euonymus has started to grow small roots, you can start to reduce the watering. Make sure that the soil dries out between watering, to avoid root rot. For the first year or so, you don’t want to stress your new plant.
So, don’t let it get too dry so that it wilts or loses its leaves, and keep it in a sheltered location away from extreme temperatures and cold winds.
Keep the cutting in a pot for a couple of years, before transplanting it outdoors in the Spring. By this stage, it will have developed a tough root system and should be in active, vigorous growth.
Pests and diseases
Although euonymus is generally easy-maintenance, there are some pests and diseases that can attack the shrub.
Fungal diseases need to be prevented if possible, as a serious attack can kill euonymus.
Powdery mildew is a type of fungus and is in itself not too serious, but it can lead to more serious diseases so should be treated with a fungicide spray. You will notice that the surface of the leaves begin to look as if they are coated in a powder. This is the deposit of spores on the plant’s foliage.
If not treated, the euonymus will become stressed and new growth will be stunted. Leaf drop may follow. To prevent this disease, make sure you keep good airflow through the plant’s branches.
This can be achieved by regular pruning and by keeping the base of the plant free from decaying vegetative matter. Always remove dead or diseased wood as soon as you notice it.
Root rot is the name given to a serious fungal attack. Once it has taken hold, the plant’s roots will rot and the top growth, such as the leaves and stems, will die.
There is no cure for an advanced state of root rot, and it will probably kill the euonymus. A young plant is more susceptible than an established shrub. Root rot can be caused by insufficient or excess water, poorly draining soil, or damage to the plant tissue.
If you are able to catch it in time, you may be able to save some of your euonymus plants. Cut out any infected parts of the euonymus shrubs.
Your tools must be wiped clean and sterilized after each use, otherwise, you will transfer the fungus to neighboring plants. Make sure you dig up, remove and burn all infected plant parts.
During the spring, if there has been excessive rain, another fungus may attack the euonymus shrubs. This may be a leaf spot, or it may be a more serious fungal disease known as anthracnose.
The leaves and stems will develop small spots of discoloration. Substantial quantities of leaves will dry up, crack and fall prematurely.
As with root rot, it is important to clear the dead leaves and branches from around the plant to stop spreading the disease further. Additionally, remove any branches or leaves that show symptoms of the disease, and then treat the whole plant with a fungicidal spray at regular intervals.
If you see round or bulbous growths on the stems of your euonymus, this is likely to be a symptom of crown gall. Crown gall can occur on the roots or anywhere on the top growth.
An infected plant should be dug up and if possible burned, together with any plants and soil immediately around the roots. Under no circumstances should you add this material to your compost heap.
Although the plant may live for many years whilst suffering from crown gall, the disease will not go away, and it cannot be treated. Unfortunately, if you don’t dispose of your plant, it is likely to spread to neighboring plants as thousands of plants are susceptible to this disease.
As for pests that may attack the euonymus, the most frequent pests to target the shrub is scale. These are tiny, sap-sucking insects that can cover the plant, and the female scale insect will also lay its eggs on the leaves.
If left untreated, scale insect has the potential to kill the whole of the euonymus shrub. However, it is more likely that the leaves will develop brown colored spots, and possibly some of the shrub’s branches will die back.
A light infestation of scale insects can best be dealt with by removing the insects by hand and then treating the plant with an organic insecticide or horticultural oil.
Certain species of euonymus are more resistant to scale insects than others, so check the plant label before purchase if you don’t want to have to worry about scale insect attacks.
Temperature and Humidity
Euonymus shrubs have thick, leathery leaves. These adapt to dryness in the air, so euonymus can make an ideal houseplant. However, euonymus is an adaptable plant and will still thrive if there is additional humidity in the air.
The ideal temperature for euonymus is between 60° F (21° C) and 80° F (29° C).
Other Uses for Euonymus
Euonymus wood was used for the manufacture of spinning wheel spindles. This is how the shrub acquired its common name of spindle tree in the United Kingdom.
Fruit-bearing euonymus shrubs provide a food source for certain bird species that eat and disperse the seeds.
Although some parts of euonymus are poisonous to humans, some species are also used medically.
Types of Euonymus You Can Grow
There is a wide range of euonymus varieties; deciduous, evergreen, low-growing, climbing, and variegated, the list of species available is seemingly endless.
One very popular variety in gardens is the green and gold leave evergreen, known as Euonymus fortunei “Emerald n’ Gold”. This will not grow more than 3 feet or 1 meter tall.
This variety doesn’t grow too slowly, and therefore won’t need a lot of pruning.
Similar varieties of E. fortunei include those with green and silver foliage, such as “Silver Queen”.
E. japonicus is a great choice for hedging as it grows quite fast. You will get the required coverage and also have lovely looking yellow and green variegated foliage, as well as pink fruits in the Autumn.
Unfortunately, however, E. japonicus, is a species of euonymus that is most susceptible to euonymus scale insect.
The commonest form is E. alatus, commonly referred to as Burning Bush due to its brilliant and deep red foliage color in the fall.
Conclusion
These flowering shrubs, in the staff vine family, are not grown for their inconspicuous floral display, but for their attractive, glossy leaves, dense growth, and often brilliant-colored foliage in the fall.
Just try to make sure that you are not planting a shrub that is considered invasive in your region.
*image by anmbph/depositphotos
