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You can plant clematis as close as 18 to 24 inches apart, and that’s the sweet spot for most varieties.
But the real answer to how close you can plant clematis to each other depends on the specific type, the size of the root system, and how much space you’re willing to give them to climb.
If you’re wondering how close you can plant clematis to each other without causing crowding, you’ll want to think about mature width, not just the size of the young plants you bring home from the nursery.
Planting clematis too close together can lead to poor airflow, which invites fungal diseases, and it can also create a messy tangle of vines that’s hard to prune.
In this post, we’ll break down the ideal spacing ranges, why the distance matters, and how to adjust based on your garden’s conditions.
Let’s dig into how close you can plant clematis to each other so you get a lush, healthy display without the headaches.
Why Spacing Matters When Planting Clematis
Spacing is one of the most overlooked parts of planting clematis, but getting it right makes a huge difference.
When you plant clematis too close, the roots compete for water and nutrients, which slows down growth and reduces blooming.
Clematis are hungry, thirsty plants, and cramming them together means neither one gets what it needs to thrive.
Another big issue with planting clematis too close is the lack of air circulation.
Clematis leaves that stay damp and crowded are prime targets for powdery mildew and other fungal problems.
And when the vines intertwine too tightly, you’ll struggle to tell which stems belong to which plant, making pruning a nightmare.
So while you can plant clematis close together, you don’t want to go below that 18-inch minimum unless you have a very compact variety.
1. The 18 to 24 Inch Rule
The standard recommendation is to plant clematis 18 to 24 inches apart, and that’s a great starting point for most garden varieties.
For smaller, non-vining types like alpina or macropetala, you can plant clematis at the closer end of that range, around 18 inches.
For vigorous climbers like jackmanii or montana, you’ll want to push toward 24 inches or even a bit more.
These fast growers need room for their roots to spread, and they’ll also produce long, thick vines that need space to branch out.
If you’re planting a row of clematis along a fence, measure out the spacing carefully so each plant gets its own defined zone.
2. Consider the Mature Size of Each Variety
The single biggest factor in how close you can plant clematis to each other is the mature size of the plant.
A clematis that tops out at 6 feet tall needs far less space than one that climbs to 20 feet.
Check the plant tag or do a quick search before you decide on spacing, because guessing can lead to trouble down the road.
For compact clematis that stay under 4 feet, you can plant them as close as 12 to 18 inches apart without issues.
For those mid-sized climbers that reach 8 to 10 feet, stick with the 18 to 24 inch rule.
And for the real giants, give them at least 3 feet of space so they don’t choke each other out.
3. Root Competition and Soil Preparation
When you plant clematis close together, the roots are going to interact, so soil prep becomes extra important.
Before planting clematis, dig a hole that’s at least 18 inches deep and wide, and mix in plenty of compost or aged manure.
This gives the roots a nutrient-rich zone to grow into, which helps offset the competition when they’re planted close.
Clematis also like their roots kept cool and shaded, even though the tops love full sun.
If you plant clematis close together, the foliage will naturally shade the base of the plants, which is a nice bonus.
Just make sure you add a layer of mulch around the base to keep the soil moisture consistent.
4. Airflow and Disease Prevention
One of the main reasons people ask how close you can plant clematis to each other is because they worry about disease.
And they’re right to worry, because poor airflow is a major trigger for clematis wilt and mildew.
When you plant clematis too close, the leaves stay wet longer after rain or watering, and that’s an open invitation for fungal spores.
To keep your plants healthy, make sure there’s enough space for air to move freely through the canopy.
If you’re planting against a solid wall or fence, you might need to give even more space than the minimum because air can’t flow through the barrier.
Regular pruning also helps open up the plant and improve airflow, even when spacing is tight.
Best Practices for Planting Clematis Close Together
If you’re set on planting clematis close together, there are a few tricks to make it work well.
First, always train each vine on its own support, or at least give them separate sections of the trellis to climb.
This prevents tangling and makes it easier to prune each plant individually.
Second, feed your clematis more frequently when they’re planted close, because they’ll be draining the soil faster.
A balanced fertilizer applied in spring and again after the first flush of blooms will keep them happy.
Third, water deeply and regularly, especially during the first year while the roots are establishing.
Clematis planted close together will pull moisture from the soil quickly, so don’t let the ground dry out completely.
And finally, keep an eye on growth during the summer and trim back any vines that start to encroach on their neighbor.
1. Choose Compatible Varieties
If you want to plant clematis close together, pick varieties that have similar growth rates and sizes.
Pairing a slow-growing alpina with a rampant montana is asking for trouble, because the montana will smother the smaller plant.
Instead, group clematis that bloom around the same time and have similar vigor.
This way, you get a nice mix of colors and textures without one plant overpowering the other.
2. Give Each Plant Its Own Support
Even if you plant clematis close together, you can keep them separate by providing individual supports.
Use a single obelisk per plant, or install multiple wires or strings on a wall so each vine has its own route upward.
This keeps the vines from intertwining and makes it easier to see which stems belong to which plant.
It also helps with pruning, because you won’t accidentally cut off a neighbor’s growth.
3. Mulch and Water Thoroughly
Clematis planted close together need a little extra care when it comes to moisture and temperature.
Apply a thick layer of mulch around the base of each plant, which helps keep the roots cool and retains moisture.
Water deeply at the base of each plant, rather than splashing the leaves, to reduce the risk of fungal issues.
During hot, dry spells, you might need to water every other day, because close spacing means the soil dries out faster.
With the right care, you can plant clematis close together and enjoy a stunning wall of color.
So, How Close Can You Plant Clematis to Each Other?
You can plant clematis as close as 18 to 24 inches apart, and that’s the ideal range for most types.
Compact varieties can go a little closer, while large climbers need more breathing room.
The key is balancing your desire for a full look with the need for airflow, root space, and ease of maintenance.
When you plant clematis close together, you’ll see a denser display faster, but you also take on more responsibility for feeding and watering.
Start with the 18-inch minimum, and increase the spacing if you notice any signs of stress or disease.
Hope this helps you figure out how close you can plant clematis to each other in your own garden.
Happy planting, and enjoy those gorgeous blooms!