Growing Clematis Successfully

Exposure: Despite what you may have heard or read about Clematis liking their heads in the sun and feet in the shade, we have found that growing these vines in part shade is ideal. Full hot sun during the summer months can cause leaf scorch and fade flowers. (SF & coastal areas full sun OK) There are a few varieties that can grow well in full sun, such as the viticella and texensis species, but for most varieties, ideal positioning would be morning sun until 1:00, or filtered bright light all day. Most people overemphasize the cool roots aspect and go to great lengths to address this. The time to be concerned about cool roots is if the plant was in a raised bed or a container exposed to radiant heat. They are naturally deep rooted and find their way easily.
Soil Preparation: Clematis enjoy a rich soil well amended with compost, well-aged manure or fir bark. The planting hole should be a min. of 18” x 18”. Mix approx. 2/3 of your native soil to 1/3 soil amendment, then mix a handful of bone meal into the soil. Position the base of the plant 2” or so below the soil level, with one set of the buds buried. This is so if the plant is severed at the base by accident, you will still have a viable pair of buds underground where it may sprout new growth. A thick layer of mulch, 2-3” of bark or shredded cedar at the base of the plant will insulate it from heat and help to retain moisture.
Watering: Sorry, no drought tolerance here! Clematis are thirsty vines and will perform best, providing you with vigorous growth and abundant flowers, if watered regularly, especially during hot summer months. Deep and thorough watering twice weekly would be a minimum. Observation will best determine what is needed.
Feeding & Mulching: Starting in March and continuing thru Sept., a monthly fertilizer schedule will spur your plants along nicely. We recommend any well balanced all-purpose fertilizer; either 12-12-12 or 16-16-16. Maxsea is a sea kelp based fertilizer we use on our plants. It contains essential micro nutrients vital to plant health and vigor. Another option would be timed released pellets such as Osmocote. Remember, it is a big effort to produce those spectacular flowers, so replenishment will only help to perpetuate an already good thing!
Staking & Tying: Clematis need support to grow on and some help from you in doing so. They do not self-attach with suction feet as other vines do, but rather by the leaf axle gently twisting around its host and grasping hold. To grow on posts or fences you may either erect a trellis or try our method. At the hardware store you will find 1” romex staples in the electrical dept. Pound these half way into the wood along a fence in a fan pattern, or at regular intervals up a post. As the vine grows, tie stems to staples with stretchy plastic garden tie.
Pruning: We recommend NO PRUNING for clematis in the Montana group, or for the evergreen varieties 'Armandii' or 'Avalanche.' For all others, in their first 2 years, prune to a pair of buds 10-12" from ground level in late winter, before any spring growth appears. Then, starting year 3, prune down all growth to 2-3' from ground level. Feed with a good 16-16-16 fertilizer such as Osmocote or Maxsea at this time and sit back and wait for the show! After this first flush of blooms is over and what is left is mostly seed heads, it is time to prune again. To promote a second spectacular show of blooms, this time in the fall, cut the whole vine back by about 1/2. And feed again. Hard pruning stimulates lots of growth, and lots of growth means lots of blooms. You will get color all the way to the first frost! Just check out our display Clematis for solid, colorful, and highly bloomiferous proof that this method works.
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