How to Grow Clematis Easily

Select healthy examples, plant correctly and give your relatively young plant the best chance to get through that crucial first winter. Three easy steps to give your new clematis plants the best start.

How to Select Healthy Clematis

Before you buy any clematis tip the plant out of its pot. Check for ‘stowaways’ and an abundance of healthy white roots. If the former is present and the latter is not, choose another plant. From the outset you do not want to import any problems or poorly plants in to your garden.

Planting Clematis for Great Results

Clematis are sold in taller pots for a reason. They need to be planted with the top crown of the plant around 2-3 inches (50-75mm) below ground level. This dramatically reduces the risk of clematis wilt. You can add a light winter mulch in addition to the above, but do remember to reduce it once the ground hits +3C to encourage early growth. This is where a ground thermometer can be very useful in spring to monitor your plants.

Clematis enjoy cool roots and warm sunny foliage with friends. Try to ensure the area above the roots is shaded during the hottest part of the day. Avoid using a slab over the roots as this can heat up quickly and reduces air and rain to the plant. Think of clematis as social plants that like to ‘mix it’. Clematis are much more likely to be successful when they are not isolated and exposed on a lattice. Instead, let them mingle with a rambler rose, a honeysuckle or a wisteria. In more extreme locations, plant an all-season shrub like Osmanthus to screen their base at a distance. Together they will protect each other from damaging cold or drying winds according to the season.

If you wish to grow a clematis near a masonry wall do be sure to plant it around 2ft (600mm) from the wall to avoid planting your latest specimen over the foundation slab that will greatly reduce any root expansion. If your proposed clematis is one of the shorter types, say 6-8ft, try to relocate it as the 12ft+ varieties, like the montanas, do best against a masonry wall.

Clematis can be planted close to a wooden fence without problem since their roots can easily negotiate the posts. However, try to avoid planting clematis roots immediately beneath a treated fence as the water run-off can be a source of contamination. Without doubt, the best place to locate a clematis is to allow it to run through another shrub or ornamental tree. Clematis Perle d’Azur can be seen growing through its protective Pittosporum support.

Consider planting two different clematis varieties together, one early-flowering, the other late-flowering with a mid-season flowering shrub for best results.

Winter Treatment for Clematis

This is the most important step to ensuring your new clematis plants get through the winter OK. Here’s the usual scenario… People buy a clematis in the spring or early summer and then often leave it well alone in the autumn believing it will be bigger and better in the following year. Big mistake, because the young root stock can exhaust itself trying to keep the whole plant alive during a long winter. Here’s what to do to give your new plant the best chance of success.

During the autumn after flowering, chop your plant down to between 12 and 18″ (30 – 45cm). Ensure the remaining stem is supported off the ground. That’s it! The young root stock can then save its energy for the winter ahead. Repeat this again for the second winter after purchase. The root stock should then be mature enough not to require a third successive autumnal chop.