How to Care for White Clematis: A Growing Guide

Scientific name: Clematis Henryi | Blooming season: Summer

👍Loves: Moist, well-drained soil; six hours of sunlight per day. | 👎Hates: Storms, pests

If you’re interested in brightening up your garden for the summer, the white clematis henryi might be the plant for you. With its standout white petals and mountainous size (6-8in across 15-20cm), it will always catch you and your guests’ attention. Fancy growing one? In this guide, you will find all the essential information you need to know about them and how to get the best results out of growing your own white clematis.

Guide contents

Getting to know your White Clematis

  • History and alias
  • Inner contents
  • Size and space
  • Tying in
  • Seasonal precautions

Planting your White Clematis

  • Planting in the ground
  • Planting in a pot

Watering and feeding

  • Watering
  • Container-grown
  • Feeding

Pruning a White Clematis

Harvesting your White Clematis

FAQs

Getting to know your White Clematis

History and alias: The white clematis henryi has been around for hundreds of years and is considered to be one of the largest white clematis plant. As there are many groups of clematis, Henryi belongs to the second group.

Inner contents: The white clematis should always be handled with precision. Not only can its root and branches easily snap, but its compounds hidden within can lead to internal bleeding inside the digestive tract if eaten in large quantities. In addition, the essential oils within the white clematis can also cause irritable skin and mucous membranes.

Size and space: Unlike other flowers in your garden, the white clematis likes to have its own space, and as it gradually grows, it’ll want even more room to grow and flourish its vines. White clematis can grow up to 1m tall but can spread less than 1m. They are also vigorous growers and like to grow along brick walls and mesh. When planting your white clematis, make sure it is close to a building structure, but it will need a partly shaded area too.

Tying in: Your white clematis will need tying in which will aid the gilded stems spread out more evenly with their support. This will help improve the flowering process and will prevent the clematis from growing into a tangled mess of foliage. At the same time, the clematis stems are very fragile, so you will need to tie these carefully, preferably using loose knots and not plastic ones, as this can lead to damaging the stems.

Seasonal precautions:

  • Summer: When growing in summer, white clematis henryi must be shaded from a western angle to avoid the leaves getting sunburnt. Shading the clematis will also keep the roots cool when using compost.
  • Storms: During stormy weather, the clematis will require more attention so that the vines do not bend or break, as their epidermis can also crack and break easily. The branches will need handling gently, too.
  • Winter: Western white clematis is very vulnerable to cold temperatures and needs protection from frost. It would be best if you used a sustainable covering around the plant or store it temporarily in your greenhouse.
white clematis henryi bunch

Planting your White Clematis

There are various ways you can plant and grow your white clematis. This may depend on the conditions and size of your garden, so please find which method below will be more suitable for you to grow your white clematis:

Planting in the ground

You should plan between the start of spring (March) to mid-autumn (between late August to mid-November) as the soil will be the warmest and moist during these times, providing good root support for the clematis.

As mentioned, you should allow plenty of space in your garden for the clematis to grow because they are agile climbers and will be a nuisance if confined to small areas.

The clematis stems will grow best from plant supports like shrubbery and will want to twine around the trellis and mesh attached to walls or fences.

Ensure the clematis has at least six hours of sunlight per day.

If your clematis has already flowered, is prominent in structure and is a hybrid cultivar, plant it between early to late summer, with the top root ball about 5-7.5cm (2-3in) below the soil’s surface. This process should encourage new shoots to grow from below the ground level and aid the clematis towards recovering if affected by clematis wilt.

Monitor that the soil pH is between 6-7.5.

Clematis is vulnerable to accumulated water or drought which can lead to it losing water quickly.

If the clematis is planted against a wall or fence, ensure the planting hole is deep enough to accommodate the root ball (between 30-45cm / 1ft – 18in), or even further if there is debris like guttering or an overhanging roof which could delay how much sunlight the clematis will receive. Using a bamboo cane will help to measure the plant’s maximum support reach.

The clematis will need its roots kept cool, so dress the top layer of soil with pebbles and keep it near low-growing plants.

Planting in a pot

If you have bought your clematis in a container or pot, you should plant it in the summer and water regularly in case of drought.

The pot should be roughly 45cm (18in) wide, and use soil potting compost like John Innes No. 2.

Keep low-growing plants in the same container as the white clematis. Alternatively, position other planted containers towards the sunward side.


Watering and feeding

Watering and feeding are the most important factors when growing your white clematis but should only be done occasionally.

1. Watering

  • White clematis will require watering regularly during dry weather, especially during the first seasons of its plantation. After a few months, when the clematis is adequately established, it will not need watering as often unless it grows on free-draining soil or if the is a long hot, dry spell.
  • If the white clematis is growing in the ground, this will require about four watering cans per square metre or equivalent.

2. Container-Grown

Container-grown white clematis require more care and attention. They should be watered most days from April (mid-spring) and October (mid-autumn) whilst having consistently good moisture levels during dry weather at other times of the year. Monitor and moisturise the soil to a depth of 30cm (1ft).

3. Feeding

  • When your white clematis is growing in the ground between late winter and early spring, it will need to be fed a steady amount of potassium-rich fertiliser, which will encourage flowering, such as Vitax Q4 or rose fertiliser. Pour the feed around the plant’s base or follow the manufacturer’s instructions.
  • Include Mulch in this process and adds it immediately after feeding with it organic produce (rotten manure, lead mould or garden compost. This will improve the soil and conserve moisture.
  • Container-grown white clematis will need feeding monthly between spring and summer using a general-purpose liquid fertiliser.

Pruning a White Clematis

Although the clematis has a reputation towards being difficult to prune due to its delicate structure, you should proceed with caution when pruning it. When you have planted your white clematis, it can be cut back to 15-30cm (6in-1ft) just over the bud.

If bought in the autumn, you should prune the clematis in February or March once it has been planted, and if planted in the spring, then prune immediately after planting.

When new growth occurs, you can pinch out the younger shoots to allow more branching from the flower buds.

The white clematis also has three flowering periods:

  • Group one: White clematis that flower in late winter or spring will likely have shoots on that were produced the previous summer (spring bloomers).
  • Group two: big-flowered cultivars that flower in early summer months, mainly May and June, will produce flowers on short shoots from last year’s growth and have a later flush on new growth (repeat bloomers).
  • Group three: White clematis plants that flower from mid-summer (late June onwards) will have new seasonal growth and herbaceous types (summer or fall bloomers).

You should therefore monitor the flowering time the white clematis will fall under:

  • Do not prune if the white clematis blossoms before early summer (June)
  • Prune in the late winter (February) if the clematis flowers from late June onwards

Find out more about the different groups of white clematis

Harvesting your White Clematis

Once your white clematis has flowered and is ready for harvesting, the flowers can be used for bouquets, decorating tables or rooms. You can choose either half or nearly open flowers but cut using a sharp knife to cut the end of the stem obliquely. You should promptly insert the flowers into clean water in a vase and keep them out of direct sunlight.

Become a White Clematis expert

White clematis is a trendy flower amongst florists and gardeners. Still, it can also be a complex plant to take care of, not just because of its size and fragile vines but also because of how vulnerable it can be to pests, such as aphids and slugs, whilst container-grown clematis can suffer from vine weevil larvae. These problems can arise from unsuitable weather and growing conditions, so you must keep the plant protected, such as using pesticides or low fences to stop bugs from getting too close to it.

However, with enough patience and care, your white clematis will provide satisfactory results by the time the harvesting period arrives, depending on the time of year it is planted and when it blossoms. It is sure to bring a fresh look to your garden and give it a vibrant atmosphere with how vigorous it will stand out amongst your other plants.

Read more on keeping your garden a pest-free zone.

FAQs

Why won’t it blossom?

–              Unsuitable weather conditions. They need to be well-moist, have well-drained soil and the roots are cool and shady. If the top of the clematis in kept in the shade too long, this will affect its growth and flowering. Therefore, place stones or pebbles around the base of the plant, to ensure only the base is in the shade.

Do you cut back clematis every year?

–              Usually in March, and the stems should be cut back 12 inches from the ground to allow fresh growth for a strong set of buds.

Is clematis better in pots or ground?

–              You will get better results from clematis growing in large pots, especially if your country’s climate has cold winters. Potting extra soil in the pot will provide more protection for the roots.

What is the lifespan of a white clematis?

–              White Clematis can live up to fifty years and more, and therefore they should be planted individually and carefully.

Sources

Gardeners’ World Magazine. (n.d.). Clematis groups explained. [Accessed 28/03/23] Retrieved from: https://www.gardenersworld.com/plants/clematis-groups-explained/

Garden World. (n.d.). Vitax Q4 fertiliser. [Accessed 28/03/23] Retrieved from: https://www.gardenworld.co.uk/product/vitax-q4-fertiliser/

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