Everything you need to know for growing beautiful, healthy Viburnums.
With a few different varieties growing in my landscape I’ve discovered through trial and error how to grow and care for a Viburnum shrub.
They are beautiful in spring when they are in bloom and can be grown as either a shrub or small tree.
With over 150 varieties available there is one that will suit every garden.
Can you grow them in containers? Sure you can. Displaying one of these beautiful shrubs on your patio or deck will look awesome in the spring when they are in bloom.
The Viburnums that I’m growing I have planted in the ground. They are large varieties and I don’t want to limit their size but I do have a lot of shrubs and trees that I grow in containers.
They will need a large pot which can get heavy. Putting wheels under the pot might be a good idea if you are going to be moving them around. A metal plant caddy is what I use for some of my plants in the house but they should work on patios and decks also.
A few things to remember:
You could also plant some annuals around the base of the plant to help hide the soil.
When planting your Viburnum shrub make sure you know how big it will be at maturity. You don’t want to crowd other plants or have it to close to the house or fence. And the tag should say if it needs full sun, part sun or if it will grow in full shade like the Nannyberry.
Once you have picked special spot for it to grow, dig the hole as deep as the pot and twice as wide. This will give the plant lots of loose soil to spread its roots through.
Unless you have really bad soil, I wouldn’t recommend fertilizing it when planting. After the first year, you can give it some organic compost if you think it will need it but it isn’t necessary. They are adaptable to a wide range of soil types and therefore fertilizing isn’t necessary.
The plant will need to be watered weekly the first year it is planted. Don’t let the soil dry out as this will stress the plant and it will become susceptible to pests and diseases.
Pruning is not really necessary but if you want to keep it at a reasonable size it should be done as soon as it’s done flowering. It flowers on old wood so if you decide to prune it in winter you will cut off the flower buds for next year.
If you don’t prune it, some varieties can get up to 15’ or more which could be too large for your garden but will look spectacular when it flowers if it isn’t pruned.
Another reason for pruning is if the plant starts to look old and leggy. If this happens you can cut one third of the plants old growth out the first year, then another third out the following year and in year 3 you can cut the remaining third of the old branches out. This will rejuvenate the plant and make it a show piece again.
There are many different varieties to choose from in either deciduous or evergreen and range in size from 2' up to about 30' tall.
Here are a couple varieties that I’m currently growing.
Viburnum shrubs aren’t affected much by pests and diseases but here are a few that you might see if the plant is under duress.
They are known to go after a Viburnum shrub and suck the sap out of the leaves. These tiny insects come in different colours from green, black, grey, yellow and more. If they decide to attack your plant they will come in masses and eat everything they can. Getting rid of them is easy and you can read more about Aphids and how to get rid of them here.
Viburnum leaf beetle (Pyrrhalta viburni)
These bothersome pests will do a real number on the leaves of your plant.
They chew holes in your Viburnum shrub leaves until there isn’t much left.
I had this problem on my European Snowball and just left the beetles to do their thing. I wanted to test how the plant would hold up against the beetles. The leaves were pretty beat up but the plant survived.
BUT if these beetles aren’t dealt with, then over a period of a few years they will end up weakening the plant and eventually killing it.
What happens is that the eggs will stay on your shrub over winter and hatch in May. The best way to get rid of these leaf beetles is to prune the shrub after it has gone dormant between the end of November and beginning of April. When you prune the shrub the debris that you cut off must go directly into the garbage as this will be where the eggs are attached.
You can also pick the beetles off and squish them with your fingers or put them in a pail of soapy water. You can also knock them off the plant and into the soapy water like the Japanese Beetle.
Beneficial insects such as the Asian lady beetles and lacewing larvae (which eat the leaf beetle larvae) and stinkbugs (go after the adult leaf beetle) will also help in killing the leaf beetle and their larvae.
Other pests that might appear on the plants are:
These insects are not very common but they have been known to visit the plant.
The types of plant diseases that could affect a Viburnum shrub are:
Powdery Mildew – This is a common disease that affects a lot of plants when the weather stay wet for long periods of time. It looks like white fuzz on the leaves. It usually doesn’t hurt the plant unless it gets severe. There is no need to do anything about it but you can treat it with a fungicide if it gets bad.
Downy Mildew – This looks like yellow blotches on the leaves between the veins and needs to be dealt with as soon as you notice it with fungicide. Any leaves that fall should be destroyed and not composed as this will make it spread.
Botryosphaeria canker – They look like brown bumps on the stem or trunk of the shrub or tree and will cause the leaves and stem tips to die back. Plants that go without water for too long many become affected. It’s best to keep the plant watered when it hasn’t rained for a while. Remove any affected branches and dispose into the garbage.
Fungal leaf spots – Another disease to watch for is leaf spots. They are brown to black patches on the leaves that are depressed in the leaves. This usually isn’t serious and occurs in summer if it’s warm and wet and will start on older foliage.
Taking Viburnum shrub cuttings is easy. I do this every year to produce more plants for my nursery and I’m teaching my granddaughter how to do it also. When you over winter them you will want to protect them from the strong winter winds and when they start to leaf out in the spring you will need to trim them to get them to start branching out.
The rule of thumb is to take your cutting 6 weeks after the buds start to open in April. Usually around the beginning to middle of June is the perfect time to take your cuttings. The wood needs to be able to stand up on its own and not flop over.
Cut the tip of your plant about 4” long or so. If you get about 3 nodes or leaf buds, that is about what you want. Strip off any lower leaves so you have at least 1 pair of leaves remaining. The more leaves on the cutting, the more energy will be going into the leaves instead of going into making the roots.
You can dip the cutting into a rooting hormone to give it a little help in getting started but if you don’t have any than don’t worry about it. You can still make your cuttings.
You need some kind of container with holes in the bottom for drainage. I have used cheap plastic tubs for the Dollar store and drilled holes in the bottom. You can use a colander or a plastic pot that already have drainage holes in them. Just about anything with drainage will work.
Fill it with well draining potting soil. If your soil doesn’t drain as well as you want it to, you can add perlite or Vermiculite which will help the soil drain better. I use coarse sand that I get from Home Hardware for my cuttings. It’s sandblasting sand that is made from silica sand and it’s about $30 for a 50lb. bag. You can reuse the sand many times so it’s worth the money.
Stick your cutting with the cut end down into your soil and water them. The leaves will need to stay moist until the roots develop as this is their only way to take up water.
The best way to achieve this when you are first starting out is with a plastic bag over the cuttings and pot. A white plastic kitchen garbage bag is perfect. Place the pot of cuttings inside the bag and either mist or lightly water everything inside the bag and tie the bag. Every day check to make sure that there is humidity inside and your cutting will be very happy.
In my first year of making cuttings this is the method I used and it works. After a few weeks, gently tug on the cutting to see if it has rooted. If there is any resistance then roots are developing. I would leave them until fall and you can plant them in your garden or put them in pots and give them to friends and family.
There are many uses in the landscape for these a Viburnum shrub. They would make great hedges for privacy, specimen plants, or plant them in front of a/c units or other views you want to hide. You can also use them along borders or for a screening.
There are many uses for a Viburnum shrub. How will you use yours?