Pruning of flowers will make for better blossoms later

Lo and behold, around the beginning of April, Clematis columbiana, our lovely native, sprouted plump buds and soon thereafter bloomed. It was absolutely gorgeous, with delicate, almost translucent, nodding, pale periwinkle-blue flowers. It’s been in my garden since only last year, and as it flowers on the previous year’s growth, I had pruned it only sparingly last spring and was rewarded with plentiful blossoms in April.

As the last flowers were fading from C. columbiana, its European relatives, C. alpina “Constance” and “Willy,” put on their display. They, too, are nodding varieties that bloom on last year’s growth and produce a remarkable number of flowers. “Constance” is a luscious raspberry pink, and “Willy,” its partner on the same arbor, sports very pale, icy pink blossoms. They intermingle as they grow and make it look like the same vine produces two different flower colors. After their first spectacular show, both continue to bloom sporadically throughout the growing season. The fluffy seed heads are almost as imposing.

Our other native, Clematis ligusticifolia, is a vigorous climber with a profusion of tiny white, star-shaped flowers July through September. The seed heads are particularly striking – large, fluffy, silver-gray balls that last a long time. Such an attractive vine that flowers summer through fall is always useful in a garden. This one flowers on new growth, so it is best pruned back hard in late winter.

Another one that benefits from hard pruning in late winter is C. texensis “Duchess of Albany.” It scrambles through the branches of a purple-leafed sand cherry in my garden, waits until the tree has finished blooming, and in early June covers the small tree in nodding, bright pink blossoms. It keeps on blooming until late in fall and produces gilded seed pods. It’s hard to decide which is more beautiful – the blooming sand cherry in the spring or in the late summer and fall, when the Duchess drapes its finery over the branches.

My C. tangutica, another nodding, late-flowering variety, grows up the sunny side of an Austrian pine. Last year it managed to climb quite high and spread itself over several branches that dripped with yellow, nodding, bell-shaped flowers from late July through September, followed by fluffy seed heads. I cut it back nearly to the ground each fall, and every spring it climbs upward again to find the best places to display its cheerful finery.

Although their flowers are not as large as those of their saucer-shaped relatives, these smaller varieties compensate for size with abundance and charm, and sometimes with fragrance as well. Take C. heracleifolia “Davidiana,” a sweetly scented shrub variety that produces hyacinthlike, lavender blue flowers in late July or early August and continues blooming until fall. The flowers form dense clusters and their fragrance seems particularly strong toward evening. Prune back hard in late winter.

What to do in the garden this week

“Weeds in the lawn can be treated with weed-and-feed products, but remember that using those products near trees and shrubs can attack them.

“It’s time to mow and water lawns regularly. When working near trees, avoid nicking the bark. Too much damaged bark can kill a tree, and any damage provides an opening for pests and diseases.

“If you’re planting in containers, make sure they have good drainage holes in the bottom of the pot. Plants in containers need to be fertilized every other week with a weak fertilizer solution. Why not add some decorative herbs to other container, too? They’ll add fragrance and color, and may even repel insects.

“Fertilize established perennials this month. Most of them won’t need another feeding this year. Dig up and divide summer and fall-blooming perennials – this works best if they’re still under 6 inches tall.

“Spring-flowering perennials can be cut back to 3 inches when they’ve finished blooming. If any have dead centers, dig up the entire plant, divide it, and replant the healthy young outer portions.

“Pinch back chrysanthemums and asters to make them bushier and more compact.

“For a staggered harvest in the vegetable garden, continue planting leafy greens, beets and carrots in small amounts. Remember to thin out vegetables to avoid overcrowding. Plant some extra for the food bank, while you’re at it.

“Check for those aphids, which are rampant this year. Look for distorted new growth, honeydew or sooty mold as well as aphid clusters. A strong spray of water is often enough to get rid of aphids. If there are too many, try insecticidal soap.