Growing Clematis in pots is a little more involved than planting them in the ground as they will require more attention and care to produce the best show possible. Read on to uncover some tips and tricks to make your potted Clematis a success.
You will find your Clematis will perform best if planted in a large pot, especially if you live in the colder climes. The extra soil in a larger pot will provide better protection and insulation for the roots and will allow the root system to expand sufficiently to support the plants nutrition and moisture requirements as it grows.
Ensure your pot has a good drainage hole in the bottom to be sure your plant doesn't become waterlogged. When adding soil to the pot use a good quality premium potting mix as these will have better moisture holding capacity and will come with slow release fertilisers in the mix. Clematis grow rapidly and require a good supply of nutrients to produce the best results. Although your Clematis will still grow in a cheap potting mix, skimping in this area will affect the final product.
As soon as you have planted your Clematis, install a trellis, obelisk or other support for the plant to climb on. Don't wait until your Clematis is established as you may damage the roots.
Planting in a container will impose additional requirements on the gardener to ensure their plant gives the very best results. The primary focus is to provide sufficient water to the plant, especially during the warmer months, to keep the plant healthy as soil in pots can become dry very quickly. Check your plant daily during the summer months and soak the pot whenever the top 3 to 5cm feels dry.
Because the plant is in a pot it can only access the nutrients available to it in the pot. As these are used by the plant they will be required to be replaced by the gardener. Feed the plant with a general-purpose, slow-release fertiliser such as Osmocote each spring and repeat a couple of time during the growing season. It is possible to give your plant a kick start by applying a feed of liquid fertiliser. Avoid using fertilisers with a high Nitrogen content as these will encourage leaf growth at the expense of the flowers.
Healthy Clematis will generally not require protection over the winter months although some varieties are more cold hardy than others. If you live in an area that is subject to extremes then a layer of mulch or compost will help protect the root system. Alternatively you could move the pot to a sheltered area.
There are around 1,000 varieties of Clematis, some growing up to 10m in height while others are more compact in form. Obviously you will need to select a more compact variety to have success. Another factor to consider is where the flowers bloom. Some varieties bloom higher in the vine leaving a bare and leggy base, this would not be much good for a potted plant. As a general rule we would not plant a Clematis that grows greater than 2.0m in a pot.
To get the best result from you potted Clematis you will need to watch and train it around your support. The vining varieties will tie themselves to the frame however, there are many non-vining varieties that will need your help to train and tie their stems to the frame. Early pruning after planting to encourage additional shoots and branching is recommended to give your potted display more depth.
Growing Clematis in pots can be very rewarding and provide wonderful results with a little bit of extra care.