Ten years ago, clematis enthusiast and member of the International Clematis
Society, Peter Keeping, couldn't find a single clematis plant at his local
nursery. Now, even a national grocery chain offers a wide range of these
colourful climbers, and gardeners across the country are clamouring for
Here are Peter's growing tips for successfully growing these flowering
1. When planting a clematis, it's important to bury the crown of the
plant at least two inches (6 cm) below the surface of the ground to encourage
more stems to grow from the base. The more stems the plant grows the faster
the coverage and the less susceptible the plant becomes to disease. Remove
any leaves that grow beneath the soil level. If the plant is very young
(grown in a two inch (6 cm) pot or smaller), bury the plant deeply, but
keep soil away from the stems until autumn. Then, build up the level of
the soil with compost or good topsoil when the stems have seasoned.
At the bottom and around the sides of the planting hole, Peter adds
bonemeal which breaks down slowly, providing nutrients to clematis roots
by the time they've grown into the planting hole.
Finally, Peter stresses that newly planted clematis need water, water,
water. So, water deeply and frequently until the plant is established.
2. Clematis absolutely damand good drainage. If water stands on the
surface of the planting hole, your soil needs to be amended to provide
better drainage. Either add sand to the soil, or line the bottom of the
hole with a layer of gravel.
3. Clematis roots need to keep cool. Peter likes to plant a largeleaved
hosta at the base of his clematis. The hosta leaves shade the roots of
the clematis, keeping them cool and happy. Any ground cover plant also
will serve the purpose, but Peter prefers hosta because their roots are
shallow and won't compete for nutrients with the deeply buried roots of
the clematis. If a ground cover just won't work in your situation, Peter
also recommends shading the base of the plant with patio stones or flagstones.
4. To encourage good flowering, Peter recommends sprinkling superphosphate
onto the surface of the soil at planting time. For mature plants, add superphosphate
once in the spring and again in June. Your clematis will thank you with
lots of colourful blossoms.
5. Finally, prune judiciously. If the stems of very young plants seem
thin, pinch them back to just above a set of buds. This causes the stems
to "thicken up", making them tougher and more resistant to damage. It also
encourages the plant to produce more stems, and as we noted above, more
stems means faster coverage and greater disease resistance.
Although it's difficult for someone who grows over 100 varieties of
clematis to pick favourites, Peter loves the double white blooms of 'Arctic
Queen', the medium blue of 'Elsa Spath', and the pure white blossoms of
'Duchess of Edinborough'. He also mentions two spectacular plants, especially
good for larger spaces -- the autumn blooming
which thrives even in half shade, and the very fragrant "old man's beard"
Clematis vitalba which almost overwhelms the Keepings' mulberry
tree. Two very tough clematis that Peter recommends, especially for colder
regions of the country are Clematis x jackmanii and C. Tangutica.
The latter is very freeflowering, with nodding yellow blossoms which
bloom from July to September. The jackmanii clematis is an old reliable
climber, easily growing to three metres with large, deep purple flowers.
By following these growing tips, you'll have clematis climbing the walls
of your garden in no time at all. For more information about clematis,
join the International Clematis Society. Members receive two newsletters
each year, paticipate in a Seed Exchange, and have opportunities to talk
and meet with other clematis growers in over 23 countries around the world.
Membership is $30.00 (US).