grown clematis in containers are a welcome sight
in any garden - big or small. Use them on the patio,
stand them amongst other plants in the garden to
create that instant impact, place them along walls
or fences where no facilities exist for planting
directly into the soil, or simply enjoy them in
a glasshouse or conservatory.
- Containers made from wood, stone
or earthenware (terracotta) provide excellent
root protection against summer heat and winter
cold. While containers made from plastic fail
to insulate the roots of clematis when subjected
to extremes of temperature, they can give years
of trouble-free service provided they are sited
Special attention should be
paid to ensure that the holes for drainage
are adequate. If necessary, the existing
holes should be enlarged so that the clematis
roots do not become waterlogged.
- Your container should be at least
45cm (18") deep and 30-45cm (12-18") wide. The
larger and deeper the container, the better.
- A rich, moisture-retentive but
free-draining mixture is essential. John Innes
No. 3 soil-based compost with added grit and
humus is excellent for long-term pot culture.
- Free-standing container clematis
should be given proper supports made of metal
or wood to prevent or limit wind-rock which will
cause root damage.
From early spring onwards, container-grown
clematis will demand regular attention.
- Training and tying-in the new
growths each week during the growing season will
help to achieve the desired shape to show off
the flowers and to prevent the plant(s) from
becoming a tangled mess.
- Watering is absolutely essential
and must be done thoroughly. It is important
to keep the containers well-watered from early
spring until late autumn. Thereafter, simply
keep the compost moist and prevent it from becoming
dry and dusty.
- Every fortnight use a liquid
feed (root and foliar) which contains equal parts
nitrogen and potash. This will help to ensure
a healthy and disease-resistant plant. Stop feeding
as soon as the flower buds begin to show and
recommence once the flowering period is over
and continue until mid-August. With very late
flowering cultivars, wait until the next spring
before restarting the feed.
- Prune as for a clematis grown
in open ground.
Adapted and abridged from BCS
Fact Sheet No. 3 Notes on Growing Clematis
in Containers by Mike Brown and Mary Toomey