clematis help please

Hello,

Last year i bought a clemastis called "westerplatte" it has lovely large red flowers and did very well i have it in a large pot against a trelis wall. When purchased it was a bout 2 foot tall and in full flower.

The instructions say in spring to cut down to 12 inch in year 1 and to cut down to 3 foot in year 2, all other years to cut out weak stems.

My query how do i know how old the clematis is or does it mean year 1 of me owning it as it was from a garden centre ? i really dont know which prune to do and i dont want to kill it, its about 4 foot tall at the moment as it doubled in height . thanks for any advice

 

@debrathezebra hope this info helps
Clematis 'Westerplatte' Large flowering
http://www.greatplantpicks.org/plantlists/view/1745
Culture Notes
This clematis will grow best in full sun to light or open shade. Provide a location with rich well-drained soil where it can be regularly watered during dry weather. Plant vines that are well rooted and at least two years old. In our climate planting too deeply can smother the roots, especially in heavy soils. Set young plants at the same depth they were in their nursery pots. Clematis are heavy feeders and appreciate fertilizing in spring. This clematis will blooms on old stems and on new growth, so it is best to only prune lightly in late spring to early summer once the first flush of flowers have finished. Remove congested or tangled growth and thin to the strongest stems. Well established, overgrown plants can be cut back to 12 inches tall in winter to remove large tangles, allowing robust new stems to fill out the plant, but it will not flower the next year.
Feed and water frequently throughout the growing season. This variety of clematis flowers in summer on new stems which develop from the previous year’s growth. Pruning should be undertaken in spring before active growth begins. When pruning group 2 Clematis, remove any damaged or dead stems entirely before cutting back the remaining stems to a pair of healthy buds. In spring, apply a mulch of well rotted manure or garden compost to the base of the plant in order to protect the roots and conserve soil moisture.

 

Thanks thats very helpful thanks for the advice

 

@debrathezebra your most for your thanks hope to see some piccy's when its in full bloom