Group 2 varieties bloom vigorously in spring, with a lighter second flush in summer. Flowers grow on old and new wood respectively.
These plants get only a light trim in early spring, then a harder pruning in summer to encourage a second set of flowers on new growth. These plants can also underperform somewhat in cold zones, for the same reason as Group 1s — they need warm temperatures early in the year. Typically, Group 2s have two bloom periods, but in cold regions this is often reduced to just one set of flowers on old wood in early summer.
Group 3 plants flower in late spring, summer, and into autumn, with flowers blooming entirely on new wood. This group gets cut back hard in winter, so frost damage to stems is negligible — a bonus in cold zones.
Group 3s also have the most suitable bloom period for colder regions, with flowers blooming in the warmth of early summer right up until first frost. Group 1s often develop thick, woody base stems measuring 2 to 6 inches across.
To distinguish Group 2 from Group 3, cut stems back hard in late winter to 18 to 24 inches, then note when they bloom. If they have only one flush of flowers, they probably belong to Group 3. Find our favorite Group 3 cultivar selections here. Begin your winter preparation by snipping off spent blooms using sharp, clean pruners or scissors. Clean up and dispose of cuttings as well as any vegetative debris around the base of the plants. Do this before the ground freezes, to prevent problematic bacteria and insects from overwintering there.
Read more about deadheading here. For frigid winters, or if you experience the occasional cold snap, your clematis will appreciate a generous layer of mulch. This insulates the roots, providing protection from drying winds and extreme temperatures. After the ground freezes, lay down 4 to 6 inches of aged compost, evergreen boughs, grass clippings, hay, leaf mold, or rotted manure.
Spread it in a 2-foot radius out from the stems, piling the mulch thickly around the base of the plant, making sure the crown is covered well. Once warmer temperatures arrive and the soil begins to thaw, gradually remove the mulch. Begin by removing half, leaving some in place to protect against a late cold snap.
Remove the rest once any risk of frost has passed. Evergreen species in Group 1, the C. However, should freezing temperatures set in for extended periods, their frost-tender leaves and stems can suffer extensive dieback. If your region flirts with the occasional cold spell, it may be prudent to cover evergreens with burlap or a frost blanket.
They provide a little extra warmth until the danger of frost has passed, and add a twinkle to the winter garden! Clematis can be overwintered in pots and containers, even in the coldest climates — providing they belong to the correct group for your zone, and your container is freeze-safe. Most wood, plastic, resin, metal, or fiberglass pots should tolerate an extended freeze.
After the soil in the container freezes, mulch generously around the plant base, covering the entire surface with 4 to 6 inches of material. Give containers made of resin, wood, or other materials an extra layer of insulation against extreme cold.
But Wait! Put that shovel away! Checking the root system must be done carefully by hand, so you don't damage it. Please be really gentle - use only your fingers to poke around at the roots! This is what a typical clematis root system should look like, close to the surface of the ground.
Note how heavy roots radiate out from the center. This is known as the "crown". As long as the crown is there and the roots are still pliable and orange in color, the roots are healthy. Of course, not all clematis root systems are "typical"!
Clematis virginiana has a more fibrous root system, consisting of about a bazillion fine roots. This is typical of a number of species clematis. This close-up of virginiana gives a better look at how even those bazillion little roots still radiate out from the crown. If Clematis become dry, it will cause stress to the plant and as a result become more prone to wilt.
There is no chemical control to prevent or cure wilt. All you can do if wilt strikes is to cut and prune off any effected stems and leaves. Remove all infected parts and clean the secateurs or cutters to ensure no cross infection. It is very disheartening when wilt strikes. Often the Clematis is about to get into full swing with lots of buds and then starts to wilt. The good news is that it will recover, but you do have to be bold and remove all infected parts.
Perceived garden wisdom is not to plant Clematis near a wall. Given that Clematis like it cooler, with moist shady roots, growing up a wall is a not dry area. This image shows how fickle Clematis and gardening advice can be.
Illustrated is a C. Jackmanii which is planted and growing up a wall with no signs of wilt. Any plant growing next to a wall will be a dry area, with a rain shadow and yet this mature Clematis looks splendid. So if your heart's desire is to have a lovely, large flowered clematis growing up a wall, and it has to be a late flowering variety, take a chance you may get lucky. In severe cases, leaf drop may occur. Leaf spot is generally nonthreatening and fungicide treatment is generally not necessary, according to the University of California Statewide Integrated Pest Management Program.
Remove and destroy all fallen leaves and debris. If you consistently have a problem with clematis wilt, consider only planting small-flowered varieties such as sweet autumn clematis Clematis terniflora.
Sweet autumn clematis is suitable for USDA zones 5 to 10, where it requires a bright, sunny location and moist, well draining soil. Floridata recommends keeping the roots cool by placing a flat rock or planting a shallow rooted ground cover over the root zone. Clemson Cooperative Extension recommends planting clematis deeply so that two "buds," or leaf nodes, are underground.
0コメント