Caren White is a Master Gardener and instructor at Home Gardeners School. She has been associated with Rutgers Gardens for over a decade.
When planning your landscape, don’t just consider how it will look in the spring, summer and fall. There are plants that can add interest to the winter season either through color or shape. The corkscrew hazel offers both. In the winter, its contorted branches lend pattern to your landscape, and then in the late winter and early spring, the long yellow catkins of the male flowers add a punch of color.
What Is Corkscrew Hazel?
Corkscrew hazel is a sport of the hazel tree. A “sport” is a plant or a part of a plant that looks completely different from the parent plant. The difference in appearance is the result of genetic mutation. Very often sports are sterile so if gardeners want to propagate them, they must do so with cuttings or suckers that sprout from the bottoms of the plants. Sports tend not to be as hardy as their parents so they are usually grafted onto parent root stock. The sturdy roots can help keep the sport plants healthy.
The corkscrew hazel was discovered in an English hedgerow in the mid-1800s by Canon Ellacombe, a Victorian era gardener. It acquired the nickname “Harold Lauder’s Walking Stick” in the early 20th century. Harold Lauder was a popular Scottish entertainer who used branches from a corkscrew hazel as walking sticks. The nickname is still in use today. You will see it in plant catalogs and on nursery plant labels.
The corkscrew hazel (Corylus avellana 'Contorta') is a large multi-stemmed shrub that grows between 8 and 10 feet tall and equally wide. It is hardy in zones 4 through 8. Its characteristic feature are the branches which grow twisted instead of straight, sometimes even growing in spirals. The contorted branches are not easily seen during the growing season when they are hidden by the foliage but in the fall and winter, when the leaves have been shed, the branches take center stage providing winter interest in the landscape.
Almost as spectacular are the flowers. Bloomtime is late winter and early spring. Each plant bears both male and female flowers. It is the male flowers that command attention. They are in the form of catkins. Catkins are long spikes of flowers that instead of growing upwards on a stiff stem, grow downwards on a soft, flexible stem. They move in the wind which blows the pollen onto the female flowers. The female flowers are red and much smaller.
How to Grow Corkscrew Hazel
Corkscrew hazel grows best in full sun but will tolerate some shade. They need well-drained soil. Newly planted shrubs should be watered regularly for the first two years as they become established. After that, no extra water is required except during periods of prolonged drought. They should be fertilized twice a year using a 16-8-8 fertilizer. The first dose should be applied in March as the growing season commences with a second and final dose in June. Use four ounces of fertilizer per one inch of the plant’s height.
How to Prune Corkscrew Hazel
Corkscrew hazels don’t require a lot of pruning. You should always remove any dead or diseased branches. Because most of the shrubs offered for sale are grafted, you should also prune away any suckers that emerge from the base of the plants. They will not “corkscrew” and may choke out the desirable branches if left on the plants.
How to Propagate Corkscrew Hazel Using Layering
Propagation is usually done by grafting but you can also try layering or soft wood cuttings. Layering is when you bend a branch of the shrub to the ground so that at least several inches of the branch is in contact with the soil. Often gardeners will remove some of the bark of the branch and apply rooting hormone to hurry the process of root formation along. After the branch is bent to the ground, it is anchored to the ground using a garden staple or even part of a metal coat hanger. I use the same pins that I use to hold down my floating row covers. This part is then covered with soil. It is important that the end of the branch with a few leaves is left uncovered to provide food through photosynthesis to the developing roots. When the roots have developed, the branch is severed from the parent and transplanted to its permanent home. Be sure to dig up the entire rootball plus the surrounding soil so that the roots are disturbed as little as possible.
How to Propagate Corkscrew Hazel Using Softwood Cuttings
Softwood cuttings are taken in the spring when the plants are actively growing and producing new, soft branches. Cuttings should be taken from a new branch and include the growing tip. The cut end of the cutting is usually dipped in rooting hormone to encourage root growth and then the cutting is inserted in soil up to half its length. For instance, a four inch cutting would be inserted two inches deep. You will know that roots have developed when the upper part of the cutting starts growing new leaves. A light tug on the plant will tell you if the roots are there or not. If there is resistance when you tug, the cutting has roots. If, instead, the cutting easily moves, no roots have grown yet.
Corkscrew hazel can be grown as a single specimen plant in your yard or as a hedge. Its contorted branches and bright catkins lend interest to your yard during the drab winter season.
Questions & Answers
Question: I want to plant a corkscrew hazel near my house, but don't want a problem with roots at my foundation. Do the roots spread?
Answer: As a rule of thumb, the root system on a plant is the same width as the foliage above ground. Remember, when planting a shrub near your home, make sure to plant it a minimum of 3 feet away from your foundation. Larger shrubs should be planted at least 5 feet away.
Question: What is the root system of an established corkscrew hazelnut? We are looking to dig up one from a house next door going for demolition and would like to move it to our yard. It's about 6 feet tall.
Answer: A good rule of thumb is that the root mass of a plant is equal to the size of the plant above ground. You might want to hire a professional to move the bush. They have machinery that can dig up and move trees and other larger plants.
Question: Could I leave corkscrew hazel in a planter or pot over the winter as long as I cover it?
Answer: Corkscrew hazels are large shrubs (eight to ten feet). They are not suitable for growing in containers. They should only be planted in your garden.
Question: Would it be a bad idea to plant corkscrew hazel beside a pond?
Answer: Corkscrew hazel requires well-drained soil. Soil that is close to streams, lakes and ponds is too wet causing root rot which will kill corkscrew hazel.
Question: What is the best time to transplant a corkscrew hazel?
Answer: The best time to plant any shrub is in the fall so that the roots become established before the plant goes dormant. You can also plant shrubs in the spring. Plant them in early spring before the weather gets too warm. The heat will stress newly planted shrubs.
Question: This article advises watering regularly newly planted hazel. What does this article mean by watering "regularly"? Approximately how often and how much water each time? I planted a corkscrew hazel about a month ago, it is now almost 4 ft tall. If I use a moisture meter, how long do I wait before watering? I have about 3-4 feet nice topsoil which I have amended to be decently drained, unfortunately underneath is clay. Please some more details on watering.
Answer: "Water regularly" means don't allow the soil to dry out. You want to keep the soil moist, but not wet. About 1 inch of water each week should be enough. That includes any rain that falls. Use a rain gauge to determine how much rain falls during each storm. If it is less than an inch, you will need to water your shrub so that it gets a total of 1 inch of water that week. You can also add a thick layer of mulch, about 2 to 3 inches deep, around your shrub to help keep the soil moist. Don't let the mulch touch any of the stems. It should be covering the soil but not touching your shrub. Mulch should never touch your plants, shrubs, and trees. Those cones of mulch that you see are actually killing the poor trees. When mulch touches a plant, shrub, or tree, it provides cover for destructive insects and small animals to live in. They will chew on and ultimately kill the plant/shrub/tree.
Question: I rooted a corkscrew I received in a vase of flowers. Left alone in the water, it has developed many roots and a few green leaves on top. It is late November now and too late to plant outside. Can I pot it up & leave it indoors till spring? If so, how would I care for it?
Answer: It is extremely difficult to grow trees and shrubs indoors. You can pot up your seedling, but don't be discouraged if it dies. It will have its best chance of surviving if you provide it with grow lights since our homes are very dark (for outdoor plants). You should also mist it a few times a week. The air in our homes is very dry, too dry for most outdoor plants.
Question: How big is the root system of the corkscrew hazel?
Answer: As a rule of thumb, the root system of a plant is the same width as the foliage above ground.
Question: Is the mutation involved in the creation of Corkscrew Hazel known?
Answer: Yes, although it is not a common mutation. There are other shrubs that have the same mutation such as the swarf caragana (Pea Tree) and the family of Robinia which is made up of about 20 species of deciduous trees and shrubs.
Question: Can you grow corkscrew hazel from seed?
Answer: Unfortunately, no. Like most sports, the seeds of corkscrew hazel are sterile. You need to either purchase a plant or grow a new one from a cutting.
Question: I've had a corkscrew hazel in a large pot outside in my back garden near the house for 16yrs but I feel it needs putting in a larger pot & have no room to plant it in the ground. What time of year would be suitable for replanting a corkscrew hazel?
Answer: Yes, fall is always the best time to plant or transplant trees, shrubs and perennials. Planting in the fall gives the plants the opportunity to get established and grow out their roots in their new home before going dormant for the winter. In the spring, they are ready to go and begin growing as soon as the soil warms up.
© 2017 Caren White