Profusions of flowers climbing up a trellis, spilling over walls, creeping over the garden as a showy ground cover, some even grow into small shrubs! – Clematis do it all. Here you’ll learn about the different types of Clematis that thrive in our area, how to care for them, along with easy answers to common Clematis quandaries.
Large Flowered Repeat Bloomers
When most people think of Clematis they think of ones like these. They are large flowering varieties that flower in late spring and again in late summer, their large gaudy blooms are second to none. Part of pruning group 2.
Continual Summer Bloomers
Also popular selections, these Clematis bloom all summer long and sometimes well into fall. Usually vigorous and tall, these pair well with climbing roses for a classic cottage garden look. Part of pruning group 3.
Usually having bell-shaped flowers and upright habits, these resemble a small shrub or herbaceous perennial rather than a vine. Bush Clematis bloom spring and summer, sometimes into fall. Traditionally not given a pruning group, but can be pruned like Clematis in group 3.
These are Clematis whose parents are from different species. These are some of our favorite Clematis. Because of their different parents, these Clematis tend to have unique flower traits and habits. Care for each one is unique as well.
Picking A trellis
When choosing your structure, make sure you have supports they can twine around, with a diameter 1/4” or smaller.
An old myth is that Clematis like “cool roots” and that a smaller plant needs to be planted at the base of the vine. Almost all roots prefer to be cool – that’s why they’re in cool soil underground. It is more important to make sure your soil is well amended and to mulch after planting to help retain moisture.
Moist, Well-drained Soil
How can soil be moist and well drained at the same time? The key here is organic matter. Amending your hole with compost will help create a texture of soil that is moist, but doesn’t hold water like a swamp.
Digging The Hole
Most herbaceous perennials need only a depth of 12” of amended soil. Because Clematis need to be planted deeper, and we want to force the roots to grow to lower levels than other plants, we may want to dig and amend soils to a depth of 16-18”. If amending a whole bed isn’t an option, make your hole as wide as you can without disturbing established plants.
Water down the hole prior to planting to help flush out air pockets. Place the crown of the plant around 3″ deeper than it was in the original pot. Bury the first set of entire leaves to encourage the production of strong shoots from below soil level and to discourage Clematis wilt. Add the backfill. Water in again.
Clematis like moist, but well-drained soil. Allow soil to dry out between watering. You can check moisture by sticking your finger into the soil. Watering one to two times a week, depending on heat and amount of rain, is about right. When you need to water, give the plant a good thorough drink were the water penetrates deep into the soil. You will be training their roots to go deep, where water stays available during dry spells.
According to the American Clematis Society, Clematis like low dose fertilizers such as bone meal or an all purpose fertilizer, around 3-12-12. Most importantly, do fertilize.
Your Clematis will survive, and even bloom with no pruning but, with the right pruning, it’ll grow and bloom more vigorously. Timing is important – don’t prune in the fall. It’s best to let your Clematis stay unpruned and dormant until spring. If you don’t know the specific variety of your Clematis, you can tell what kind of pruning is needed by observing when it blooms and whether it blooms on new growth or last year’s growth.
Generally the early-flowering cultivars. These plants bloom off of old wood. The only time to prune is immediately after they flower, simply containing them to their allotted space and removing any dead wood. Timing is crucial; the plants need to be able to put on new growth for next year’s blooms.
Most cultivars fall into this group. They generally bloom on old and new wood, and they usually have two successions of blooms. The first flush of blooms will come in May or June, and then again in September or August. Prune in early March. In early spring prune off dead or spindly wood, careful not to prune off old good wood or early flowers will be lost. Prune again right after first flush of blooms to encourage second bloom. Prune back some stems one-third to one-half by cutting to large buds or a strong side shoot immediately below the spent blooms.
These are generally the later flowering cultivars, which bloom on current year’s shoots. Prune these hard in February or March when buds begin to show on the plants. All dead material above these buds should be removed at this time. Also remove any old foliage or diseased foliage.
Why Won’t My Clematis Bloom?
While most Clematis bloom with ease, sometimes they just won’t bloom. Explore some of the reasons they may not bloom.
- Not enough sunlight – While there are many Clematis that are tolerant of part shade, dappled light, or bright indirect light, none love full shade.
- Too much nitrogen – If you have a full vigorous plant, but no blooms there may be a nutrient imbalance, usually too much nitrogen. A big cause from this can be fertilizer run-off from the lawn.
- Incorrect pruning – If certain types of Clematis are pruned at the wrong time their flower buds may be pruned off. If unsure about when to prune leave it alone, Clematis don’t need to be pruned every year, especially the ones that would suffer from improper pruning.
- Not enough water – Clematis need a good amount of water to set buds for those large, gorgeous flowers. If we are not receiving regular rain supplement water at least once a week on established vines and more on newly planted ones. Mulching around the base of the vine will help retain moisture.
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