Growing Curly Willow In A Container

Also known as corkscrew willow, dragon’s claw willow, and twisted willow, curly willows are native to China and Korea. But they have earned admirers all over the world due to being easy to grow, and for having unusual, meandering, contorted stems. In fact, their unusual stems are the result of a single randomly occurring genetic mutation. Since it first appeared, that mutation has been preserved by propagating new plants from cuttings called ‘withies’, which are genetically identical to their parent. This means that most curly willows are clones of one another, and here’s a fun fact: they are all female!

Curly willows grow vigorously, quickly reaching up to 30ft tall. However they are not long lived – most willows die back after just 20 years or so. Corkscrew willow’s ornamental twigs are usually brown, but some nurseries sell varieties that have yellow or red stems. These varieties are known as ‘Golden Curls’ and ‘Scarlet Curls’ respectively. They were produced by crossing curly willow with straight stemmed willows that have colorful bark.

The advantages of growing curly willow in a container

Curly willow is a beautiful plant in its own right. It works especially well in cottage gardens, contemporary gardens, and wildlife gardens. In the latter it provides a valuable safe haven for many butterfly and moth species. But lots of people grow corkscrew willows primarily in order to harvest the bare stems in fall, and use them for home decoration. The remarkable thing about this tree is that it grows so fast you can easily enjoy it both ways. Even if you remove stems in fall, they will grow back with gusto again the following spring.

Whichever way you’re most looking forward to enjoying your corkscrew willow, there are some good reasons to consider growing it in a container rather than in the open ground. Firstly, you’ll be able to contain its vigorous root system. Willow roots are notorious for invading water pipes and potentially causing structural damage to your water supply. So planting them in the ground close to your home is not advised. Their root system is also relatively shallow compared with other tree species. They have even been known to lift driveways and sidewalks.

Secondly, willows in containers can be moved around, especially if you stand them on a wheeled plant caddy. This makes it easy to show them off when they are the most interesting thing in your yard. For example, you could put one either side of your front door in winter. Then in summer roll them aside to make way for statement tender plants like cannas or ginger.

Potential pitfalls of growing curly willow in a container

Growing curly willow in a container is nearly a no-brainer, but it does have some potential drawbacks too. Firstly, containers can be prone to drying out in summer. Willows of all types love damp conditions, which is why they’re often seen growing next to ponds, lakes and rivers. They dislike dry conditions, and standing for too long in a pot that has run out of water can leaved them stressed, sad-looking, and prone to disease.

Secondly, and closely related, curly willow’s roots will quickly grow out of the drainage holes in pots in pursuit of water. If you place the pot on soil, turf or gravel, the roots will eventually penetrate the bottom of the pot and into the ground. Most growers only realize this has happened when they can no longer pick up the pot or move it! So, growing curly willow in a container also means making a commitment to regular root pruning. In other words, between the watering and the pruning, maintaining a potted curly willow and curbing its vigor is a somewhat high maintenance task. But I think it is worth the rewards!

Choosing the right pot

Choosing the right pot for your curly willow can have a significant impact on how easy it is to care for. Some factors to consider when choosing a container for your curly willow are:

• Size
• Materials
• Shape

Size

The more pot space you can provide for your container-grown curly willow, the better. Larger containers hold more water, so you’ll have to visit them with the hose less often. They also provide a stable base, meaning your tree is less likely to blow over on windy days. (Curly willow stems are somewhat brittle and prone to snapping, so you’ll notice in the next few paragraphs that I am rather obsessed with keeping them upright!) The bigger the container you start with, the fewer times your tree will need potting on too.

Materials

Planting containers come is a wide variety of materials these days. There aren’t really any right or wrong choices. But there are pros and cons that you’ll need to weigh up in order to make the best choice for you.

• Modern plastic pots from recycled materials are designed to be aesthetically pleasing and eco-friendly. They are also light weight (which makes moving your willow easier) and nonporous (which helps conserve water).
• Glazed clay containers are a handsome, traditional choice and also nonporous. They weigh more than plastic, which makes them unwieldy to move and tip up, but also more stable in windy weather.
• Unglazed terracotta pots are the only material I’d completely advise against. They very porous, and will dry out from evaporation through the sides in summer, making your willow miserable.
• Wooden half-barrels are one of the most affordable ways to give your willow a lot of space. They also have ideal proportions for willows, generally being wider than they are tall. But they don’t last as long as clay and plastic pots, and they are porous. However, you could line them with an empty compost bag to stop water evaporating out of the sides.

Shape

Curly willows grown in containers need to be tipped out and root-pruned roughly every other year. This is much easier if you choose a tapered pot, and avoid containers with a lip around the top. However, tapered pots topple over more easily than pots with straight vertical sides. So if your yard is exposed, you’ll need to decide what your bigger priority is.

Looking after your potted curly willow

Twisted willows are very vigorous, and don’t need a lots of encouragement to grow away strongly. Most of their care needs actually center around curbing their growth, and keeping their vigor in check! Here’s how to make sure you get the most out of your plant:

• Position the pot away from traffic, so the stems don’t get bumped and snapped.
• Set up a drip irrigation system, or use a tree watering bag in long periods of dry weather to stop it drying out.
• One way or another, your container-bound curly willow is going to need keeping under control by pruning. This is done in early spring, around March. You can trim the canopy into a small tree shape, or you can cut the whole plant down to the ground. Take a look at the video at the top of this article for an example of how to keep a container-grown willow in a tree shape. If you cut it down to the ground it will produce multiple new stems from the stump, and take on a shrub-like shape instead. This is known as coppicing.
• Whichever way you prune the branches, every other year you’ll need to remove it from its pot and prune away one third of the roots too. This is also a good opportunity to freshen up the compost so it has access to all the nutrients it needs.
• Stand the container on pot feet so you can see when the roots start to grow out of the bottom of the pot without having to lift or tip it. When the roots appear, that’s your cue to root prune it the following spring!
• Prunes branches will readily take root in a vase of clean water, if you want to grow more stock.

Growing curly willow in a container – summary

Growing curly willow in a container is a great way to enjoy its unusual appearance without its roots damaging your property. Choose a pot which is as large as possible, non-porous, and stable. You’ll need to water your plant regular in summer, and prune it hard every spring. Every other spring, unpot your plant, trim away one third of the roots, and repot in fresh compost. Don’t be afraid of this process – willow grows so vigorously that it will bounce right back! Let us know how you get on in the comments box down below.