For the most part, Viburnum is a pretty low-maintenance guest in the garden and doesn’t usually need extra feeding. However, there are a few situations where your plants might appreciate a little nutritional boost. You’ll want to consider fertilizing if:
- Your garden soil is naturally very poor or sandy.
- You’re growing your Viburnum in a container or pot.
Dealing with Nutrient-Poor Soil
If you’ve been keeping your garden beds well-mulched, that’s usually more than enough to keep a Viburnum happy. But if you aren’t using mulch and your soil is on the leaner side, you can give your plants a helping hand by:
- Using an all-purpose organic fertilizer.
- Mixing in some fresh compost.
Organic Fertilizers
I recommend using an organic all-purpose fertilizer if your soil tends to be dry and lacks nutrients. For summer-blooming varieties, give them a little feed every 6 to 8 weeks during their blooming season. Just make sure to stop fertilizing by early September so the plant can prep for winter. If you have a winter-blooming variety, start your feeding routine in the spring and again, wrap it up by early September.
Pro tip: If you’ve just planted a new Viburnum or repotted one, give it a break! They don’t need any fertilizer for the first few weeks. If you feel it needs a boost later on, wait at least 6 weeks before starting.
Mixing in Compost
If your soil stays on the moister side, compost is a fantastic natural option. Simply work some into the soil every 6 to 8 weeks while the plant is in bloom.
Container-Grown Viburnum
Plants living in pots are a bit more high-maintenance than their friends in the ground. Since their roots are limited to a small amount of soil, they run through nutrients much faster. For container Viburnums, I suggest using a fertilizer specifically formulated for flowering plants. These usually have a bit more phosphorus, which is exactly what the plant needs to put on a great floral show.
Generally, potted plants can handle a light feeding once a month. However, every plant is different depending on its size and how much sun it gets. Since over-fertilizing can actually hurt your Viburnum, it’s always better to start with a light hand and slowly increase the dose if the plant looks like it needs more.
The Dangers of Over-Fertilizing
When it comes to Viburnum, you can definitely have too much of a good thing. Over-fertilizing—especially with high-nitrogen products—can lead to fewer flowers and make your plant a magnet for pests and diseases. Remember: when in doubt, less is more!
