Clematis are popular perennial climbers, providing height and colour throughout the season. They look particularly good with roses. You can grow a huge range of clematis plants, with flowers that are as big as dinner plates or as small as bells.
Clematis can be good for wildlife because it grows leaves and flowers that cover walls, fences, and trellises, giving insects and sometimes birds a place to hide. Pollinators visit some clematis flowers, and house sparrows may use the fluffy seedheads of some cultivars of Clematis tangutica as a place to nest.
Clematis are beautiful flowering vines that can add gorgeous color and interest to any garden. With their incredible variety of flower shapes, sizes and colors, clematis allow you to choose just the right plant for your unique style. Many gardeners love using clematis as container plants, which makes it easy to position them in ideal spots around a deck, patio or balcony.
When growing clematis in pots using the right potting soil is essential for the health and performance of your plants. The soil needs to provide excellent drainage while still retaining some moisture. It should also supply the nutrients clematis require without being overly rich.
Here is a look at the best potting mixes and soil components to help your container grown clematis thrive
Well-Drained Potting Mix
Excellent drainage is one of the most important requirements for successfully growing clematis in containers Their roots can easily rot if left sitting in wet soil for extended periods
A good quality, commercial potting mix designed for containers is a smart choice for clematis pots. Avoid regular garden soil, as it will compact over time and impede drainage. Potting mixes contain ingredients like peat moss, perlite, vermiculite and bark fines to create an open, porous texture that drains readily.
You can also make your own customized blend by mixing equal parts peat moss, perlite and compost. Adding 10-20% coarse sand or small gravel improves drainage further.
John Innes Potting Mixes
The John Innes range of loam-based potting mixes are an excellent choice for clematis containers. They contain loam, peat and fertilizers. The original John Innes formula also includes coarse sand or fine gravel.
John Innes No. 2 or No. 3 work well for clematis. No. 2 has a higher peat content for moisture retention, while No. 3 contains more loam and gravel for superior drainage.
Soilless Mixes
Soilless potting mixes that contain coco coir as an alternative to peat moss also work well for clematis. Coco coir has an exceptional air to water ratio for great drainage and aeration. Mixes that blend coco coir with ingredients like bark, perlite and vermiculite make quality clematis soils.
Loam
Loam is considered one of the best soil textures for growing clematis. It has the perfect balance of sand, silt and clay to provide exceptional drainage while retaining moisture and nutrients.
When potting clematis, include at least 30% loam in your mix. Loam can be purchased bagged from garden centers or dug from your own garden if you have suitable soil. Be sure any loam extracted from the ground is screened to remove rocks, debris and weed seeds first.
Compost
Adding compost to potting soil provides organic matter to help retain moisture and supply nutrients for clematis growth. Compost offers a slow-release feeding that provides a steady supply of nitrogen and other elements plants need.
Use up to 30% good quality compost or composted manure in your container mix. Don’t use compost as more than 30% of the total volume or the soil may drain poorly and compact over time.
Coarse Sand or Gravel
Incorporating 10-20% coarse sand or fine gravel into potting soil improves drainage and moisture control.
Clean builder’s sand or horticultural sand are easy additions. Small pea gravel or crushed granite also work very well. Top dressing pots with pebbles or gravel further enhances drainage and reduces soil compaction.
pH Balance
Check the pH of your potting mix, as clematis prefer a slightly alkaline soil with a pH between 6.5-7.5. Mixes that contain peat moss tend to be acidic. Add garden lime if needed to raise pH. Follow package directions, as excessive lime can damage roots.
Organic Fertilizer
While clematis don’t require highly fertile soil, some organic nutrients are beneficial. Adding worm castings, kelp meal, fish emulsion or compost provides nutrients without making soil too rich.
Use controlled-release fertilizer at planting to supply steady nourishment for several months. Top dress pots in early spring with organic granular fertilizer or work slow-release fertilizer into the top few inches of soil.
Soil Volume
Don’t skimp on container size for clematis. Their vigorous root systems require plenty of space. Use at least a 15-17 inch diameter pot and fill it at least 75% of the way with quality potting soil.
For long planter boxes, allow at least 14 inches of soil depth and width. Give vines a strong support structure as they grow tall and heavy with lush foliage and flowers.
Mulch
Spread a 2-3 inch layer of shredded bark mulch, pine needles or other organic mulch over the soil surface in clematis pots. Mulching helps regulate soil temperature and moisture while suppressing weeds.
Replenish mulch annually. If possible, use light colored mulch to prevent overheating the container.
Watering Needs
Clematis demand consistent moisture, especially while blooming and as new growth occurs. Check soil daily and water whenever the top few inches become dry. Avoid letting containers completely dry out.
Soak pots thoroughly until water drains freely from the bottom with each watering. Consider using drip irrigation or self-watering pots to maintain optimal moisture.
Location
Situate clematis containers in sunny to partly shaded spots protected from harsh winds. Move pots to offer some afternoon shade in very hot climates. Provide winter protection in cold regions by moving pots to an unheated garage or shelter.
With a well-aerated, moderately fertile potting mix, proper watering, fertilizing and location, your container grown clematis will thrive and reward you with their delightful blossoms. Paying attention to their soil needs will keep your vines healthy, vigorous and flowering beautifully.
How to plant clematis
Plant clematis in spring or autumn. All types of clematis do best in soil that keeps water in, so dig a deep hole and add a bucket of garden compost or well-rotted manure. Mix this thoroughly into the soil.
The top of the rootball should be level with the soil or 6 cm below for large-flowered types (pruning group three). Place your clematis in the hole. Remove lower leaves, fill around the roots with soil and firm down.
Water your clematis thoroughly after planting and then every two weeks in the first three months. Clematis wilt is a fungal disease that can happen to plants. To keep the roots cool and moist, cover the soil around the base of the plant with tiles or stones.
Tie in the new clematis stems regularly using soft twine or foam-covered twist ties. Take care not to break the stems and space them evenly to maximise coverage over their supports.
Where to buy clematis online
Clematis are hungry, thirsty plants. When it’s dry, water them often, and right before they bloom, feed them with a high-potash fertilizer like tomato feed. This is particularly important when growing clematis in pots. The feed should encourage a healthy crop of flowers.
Marcel Floyd of Floyds Climbers and Clematis gives us his best advice on how to take care of clematis in our Golden Rules video. He explains why it’s important to prune them as soon as you get them. When to water them and how to feed them best are also shown: Green Video Post Element Video ID: “9d5d05f83a1c4c5a5e30ea196a38f457a42812be” Mix ID: “” Player ID: “qAUyOzk5” If the player doesn’t show up in a few seconds, the Player ID or License Key (set in IM Green Video settings) may not work.
How to Grow Clematis in Containers//Tips from world authority on clematis, Raymond Evison!
FAQ
What kind of potting soil for clematis?
Does clematis grow well in pots?
What type of soil is best for clematis?
How deep should a container be for a clematis?
Can Clematis grow in pots?
There are a few things to bear in mind, however, when learning how to grow clematis in pots if you want to be guaranteed the best display possible. The best time of year to plant clematis in a pot as part of your container gardening ideas is in spring or early fall, as warm, moist soil at these times of year helps the roots get established.
How do you grow a clematis plant in a pot?
Fill the container to within 3 inches of the rim with a suitable potting soil. Ease the rootball of your clematis plant out of the pot and nestle into the compost with the root crown buried below the surface of the soil.
When should you plant Clematis in a pot?
The best time of year to plant clematis in a pot as part of your container gardening ideas is in spring or early fall, as warm, moist soil at these times of year helps the roots get established. ‘Compact clematis grow happily in containers, as long as they are regularly watered and fed,’ says Anne Swithinbank, gardening expert for Homes & Gardens.
How do I choose a potted Clematis?
Choosing the right container is critical for the health of your potted clematis. Select a pot that is at least 18 inches deep and wide, as clematis plants have long and vigorous root systems that require space to expand. Materials can vary from wood, ceramic, or even plastic, but ensure the container has excellent drainage.
Do Clematis need a lot of water?
Clematis growing in pots will require a lot more water than one growing in the ground. That is because containers will dry out faster than the ground. Check the soil frequently, especially in the first year. If the top inch of soil is dry the plant will need to be watered. Saturate the soil when watering.
How deep should a clematis pot be?
Select a pot that is at least 18 inches deep and wide, as clematis plants have long and vigorous root systems that require space to expand. Materials can vary from wood, ceramic, or even plastic, but ensure the container has excellent drainage. Adequate drainage is essential to prevent root rot, so make sure the pot has several holes at the bottom.