Clematis

   Written by on March 27, 2014 at 11:51 am

There is a beautiful redwood arch between my yard and The Neighbor’s. In casual conversation the other day about what to plant there this year, clematis was mentioned and I think that’s a good idea. Of course, The Neighbor will not be allowed to plant anything since he has a decidedly brown thumb instead of a green one. He can do the lifting and carrying and his wife and I will plant.

logo - a walkThe planting season for flowering vines is here, along with unseasonably cold temperatures and snow, for pete’s sake. But in the interest of knowing what to do when it’s finally all right to plant, we’ll study and be prepared.

The first thing to note is that clematis will not attach itself to the redwood; it will twine around it thus not damaging the wood. Clematis grows in the sough in coo, well-prepared soil which has good drainage, high humus, and a high pH (sweet soil). If possible, it should be planted where it receives plenty of morning sun up to about noon but is not exposed to hot afternoon rays. Perfect for our spot.

Since we have had to wait this late to plant, we should look for container-grown plants at the nursery instead of bare root ones. When we get it home, we’ll (meaning The Neighbor) have to dig a wide, deep hole several times larger than the root system or ball of earth in the container. Four inches of pea gravel should go in the bottom of the hole for drainage. Marble chips would also be good for this application since they are alkaline and contribute to the high pH needed. Nest, a soil mix of one-third soil, one-third peat moss or ground bark and one-third vermiculite, or perlite if you use peat moss, should be prepared. Add to that two double handfuls of dolomite limestone like you use on the lawn. Limestone is “basic,” meaning it will raise the pH level. (All this mixing requires a lot of work and a considerable amount of money. We’ll ask at the nursery if there is a commercially prepared soil mix suitable for our clematis.)

Partially fill the hole with the soil mixture and plant the clematis shallowly with the roots at the surface of the ground. Then pack the mixed soil around the roots and water thoroughly to settle the soil. Remember: plant roots don’t like air pockets! Keep the newly planted clematis mulched with pine straw or pine bark chunks to keep the roots cool and also prevent weeds from competing for nutrients.

After the second growing season, hybrid clematis is established and should be pruned heavily each winter. The first pruning would involve cutting back the twigs and branches to the main stem and laterals, leaving a main vine with several strong branches. The second year, prune almost all the way to the ground. This will help force new growth which will produce an abundance of flowers on vigorous healthy plants.

It is important to fertilize clematis during the growing season to force heavy growth on which new buds and flowers will be formed. A double handful of 5-10-15 fertilizer every six weeks is recommended for this purpose. An easier method is to fertilize once in the spring with a slow-release, high-nitrogen fertilizer. High potassium and phosphate will stimulate flower production. Applying bone meal or limestone in the spring will help sweeten the soil, but make your choice carefully. If you have a dog, stick with limestone; dogs love the smell of bone meal and will dig up clematis trying to find that buried treat. No, New Dog, sit!

Our summers tend to be hot so the clematis will have to be soaked thoroughly during those prolonged dry spells. Seed formations should be snipped off as soon as the petals fall to help future flower formation. Pests will include the usual Japanese beetles and another beetle peculiar to clematis. We’ll need to keep Sevin on hand.

Wish us luck!

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