Companion Plants for Clematis | What To Plant and What To Avoid

You’d be hard-pressed to find a garden without at least one clematis in my neighborhood. Whether you’re looking for color, ease of care, or a climbing growth habit, these flowering vines have it all.

Clematis are also known for being good companion plants — in part because they grow up and ‘out of the way’. But you can’t place clematis alongside just any other plant and expect great results.

If you’re interested in learning more about companion plants for clematis, I’ve gone ahead and made a list of some of the best options and explained some of the benefits you can expect from different pairings.

What Is Companion Planting?

Companion planting involves growing two or more different types of plants in close proximity to each other in hopes of creating some kind of benefit. We normally think of companion planting in terms of fruit and vegetable crops but it can also be effective when growing ornamentals.

For companion planting to be successful, you need to select plants with similar needs. For example, you shouldn’t try to grow a plant that prefers dry soil with one that likes a damp environment. Things like sunlight requirements and nutrition can also interfere with prospective pairings.

Root depth and size are other things to consider when planning your garden. Companions with varying root systems — e.g., a tree with large, deep roots grown next to small, shallow-rooted annuals — work well together. The same can’t be said of plants with similar root systems grown extremely close together.

Benefits of Companion Planting with Clematis

There’s a common myth that clematis roots need to be shaded by groundcover plants for optimal growth. While this isnt strictly true, there are several tangible benefits to pairing your clematis vines with suitable companions:

1. Pest Control

Perhaps the most famous and impactful benefit of companion planting is natural pest control. While some plant species attract damaging pests, others deter them. By planting deterrents near plants that normally fall victim to insects and other wildlife, you can effectively ‘hide’ the former from its would-be predators.

Clematis themselves don’t offer much in the way of pest control. However, there are a few common plants you can grow to protect your clematis from aphids, rabbits, and other pests.

2. Aesthetic Value

One of the core tenets of good landscape design is the use of different heights within a single space. Clematis are commonly grown on pergolas, fences, or trellises that reach several feet tall. Growing shorter plants around the base of a clematis vine increases contrast and fills the empty space below.

You can also use clematis to add color and texture to tree trunks and non-flowering shrubs.

3. Seasonal Shade

Many garden vegetables prefer at least partial shade during the summer months. A well-placed clematis vine is a clever way to provide extra shade without crowding out your crops.

4. Attracting Pollinators

I’m willing to bet nearly every gardener wishes they could draw more pollinators to their outdoor space. Well, planting showy flowers like clematis is a great way to attract pollinators to your yard.

This potential benefit is incredibly important if you also grow fruit or vegetables that need cross-pollination. There’s a good chance those extra pollinators will pay your crops a visit after feeding on your clematis!

Best Companion Plants for Clematis

While a very specific flower probably comes to mind when I mention the word ‘clematis’, the genus actually contains over 300 unique species and even more genetic varieties. If it’s been a minute since you last shopped for clematis vines, you might be surprised to see how many new types are currently on the market!

The most important thing to know about clematis before we go on is that these vines are typically grouped based on when/how they bloom:

  • Group 1 varieties bloom from late winter to spring on old growth.
  • Group 2 varieties bloom from late spring to early summer on old growth. They sometimes bloom a second time in late summer on new growth.
  • Group 3 varieties bloom from summer to fall entirely on new growth.

Certain companion plants might pair better with clematis from one of these groups versus another. I’ll touch more on this below when relevant.

Vegetables and Herbs

Leaf Lettuce: Growing leaf lettuce at home is a great way to boost your summer salad intake. While lettuce generally needs 6+ hours of direct sunlight to grow, too much heat and sun exposure can trigger bolting — i.e., premature flowering.

Strategically planting lettuce next to clematis (on a trellis or similar structure) will offer much-needed protection from the midday sun. In most regions, you’ll want to grow a clematis vine from Group 2 or Group 3 for optimal summer shade.

Garlic and Onions: Members of the Allium family like onions and garlic aren’t just pungently delicious. They also provide effective pest control against slugs and snails, insects, and some herbivorous mammals. 

Alliums are primarily grown for their underground bulbs and some require several inches of empty soil space to develop. I recommend planting garlic and onions a couple of feet from the base of your clematis vine so that the roots of each plant can thrive.

Cilantro: Cilantro plants prefer cool weather and usually bolt when temperatures get too high. Placing cilantro under the shade of a Group 2 clematis vine may prolong the growing season for a couple of extra weeks in late spring.

Mint: This herb is both versatile and naturally pungent, making it an effective pest deterrent when grown in the garden. Mint tolerates sun and shade equally well, so you can surround the base of your clematis vines without worry.

Note that mint can quickly run amok when planted in the ground. I strongly suggest taking this into account and using landscape borders or planting the mint in a container to stop it from spreading where you don’t want it.

Brassicas (Cabbage, Broccoli, Kale, etc.): The Brassica family includes popular cole crops like broccoli, cabbage, kale, cauliflower, and Brussels sprouts. Like lettuce, all of these vegetables are prone to bolting when exposed to high heat.

Brassicas are usually planted in the spring for an early summer harvest or in the late summer for a fall harvest. Plant these crops next to Group 2 or Group 3 clematis vines respectively to prevent bolting at the end of the growing season.

Flowers

Marigolds: Marigolds are one of the most common annual flowers used in companion planting. Unfortunately, claims that marigolds can repel any and all pests from your garden are mostly untrue. But there is some evidence that growing marigolds near vulnerable plants can deter whiteflies and soilborne nematodes.

Even if marigolds won’t protect your clematis from all pests, they’re still an attractive and low-maintenance addition to the garden bed. I also find that the yellow, orange, and red hues of marigolds pair nicely with clematis flowers!

Sweet Alyssum: Sweet alyssum is at the top of my personal list of plants for annual pots and garden beds. The delicate flowers come in shades of white, pink, and purple. In milder climates, you can grow sweet alyssum as an herbaceous perennial.

Of course, Sweet Alyssum doesn’t just look great to the human eye. Its flowers attract all manner of beneficial insects, including those that prey on nasty pests like aphids and caterpillars. Plant sweet alyssum under your clematis vine for higher pollinator activity and natural pest management.

Ornamental Alliums: Not all members of the Allium family produce edible bulbs like onions and garlic. There are countless varieties grown for their attractive flowers instead. Though you can’t make a meal out of ornamental Alliums, they offer the same degree of pest control as their edible cousins.

Salvia (Sage): Pollinators love the flowers of ornamental salvia plants. Many varieties even attract hummingbirds! Growing a small collection of salvia around your clematis vine is practically guaranteed to draw beneficial wildlife to the area.

Common sage (Salvia officinalis) is also an effective pest deterrent but isn’t as attractive as other varieties. All salvia plants have relatively low moisture needs so they won’t compete with your clematis for water.

Hardy Geranium: Hardy geraniums, also known as cranesbills, are beautiful sprawling perennials that come in many different colors. Their growth habit and low-maintenance nature pair perfectly with climbing specimens. If your main goal is to bring balance to your garden’s design, I recommend planting hardy geranium under your clematis.

Catmint: This close relative of catnip is more often grown for its attractive flowers than for its aroma. But as a member of the Mint family, it still provides a natural defense against common garden pests.

Catmint and salvia have very similar environmental needs. Consider planting both around the base of your clematis vine for even more variety.

Shrubs and Trees

Roses: Some clematis varieties can almost be mistaken for climbing rose bushes from a distance. Though the two plants aren’t related, they mesh together incredibly well both visually and physically.

When selecting roses to plant alongside clematis, you’ll probably get the best results from groundcover varieties. Compact tea roses are another great option to consider. I wouldn’t advise growing clematis and climbing roses together because they will compete for the same space and — over time — one of the plants will likely get choked out.

Keep in mind that clematis vines and rose bushes both need plenty of access to water. Be sure to use fertile, well-draining soil and irrigate as needed to keep both plants happy.

clematis above roses

Evergreen Shrubs: Planting clematis at the base of an evergreen shrub is a clever way to add color to your landscape for part of the year. I’ve seen this done with evergreens like Euonymus and Arborvitae but there are countless potential pairings to choose from.

Wait until your evergreen shrub is well-established before training clematis to climb it. For the best results, use a Group 3 clematis variety or one of the smaller options from Group 1 or Group 2. Larger varieties may smother the shrub. 

Trees: You can also use an existing tree trunk as a ‘trellis’ for your clematis. Almost any tree species will do but this works best with established specimens that can handle the weight of the vine.

I recommend using a Group 1 clematis since such varieties don’t need to be pruned or cut back for healthy growth. You may need to train the vine early on to coax it up the tree trunk.

clematis growing on shrubs

Bad Companion Plants for Clematis

Clematis are excellent garden companions and there aren’t very many plants that won’t grow well with these vines. Nevertheless, here are a few things to keep in mind to avoid a bad pairing:

  • Stay away from other climbing plants that will directly compete with your clematis vine.
  • Avoid low-growing varieties that need 8+ hours of sun.
  • Do not grow clematis next to other plants that take in a lot of water.
  • Ensure that potential partners enjoy the same soil pH and composition as your clematis.

Citations

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Ben's horticultural interest grew when graduating from Hertfordshire University in 1997. Having contributed to numerous publications including Better Homes & Gardens, Garden Design Magazine, and The English Garden. He is also the author of Propagating Houseplants Made Easy.