Vincas

Q. Can you expound on your technique for reproducing vincas [periwinkle myrtle]? I sure would like to have more of those blue ones. And here in Houston they're often perennials.

A. There are two methods to propagate them.

Cuttings
Take the young fresh new growth as right now [June]. Cut off about 6" of the stem place in either water or what I like to use is a small flat of moist mixture of vermiculite and perlite [with sterilized sand if you like]. Keep in low light outside but not shade nor hot direct light. Roots form in about two weeks. Make sure the medium does not dry out. It will have good drainage so there should be no rot.

Separation
Take a clean sharp trowel and dig up a small plug of it where it is the thickest and won't be missed. Get down at least 6" to get the roots. Take the small clump and plant where you want it. It is a good way to fill in holes in the ground cover. Keep it well-watered until established and protect from harsh sun. Periwinkle does best in shade or part-shade as a ground cover or in large container potting.

Q. I received a nice hanging basket of white Vincas. But it's not like the Vincas I have in my yard. The leaves are more elongated and the stems droop over the sides of the pot. Do you think this is some special species of Vinca? Also how would I care for it? It is positively covered with blooms now. How would I keep it in bloom?

A. The plant you mention is not a species but a hybrid or variety of the small Vinca minor rather newish plant on the gardening scene.

Vinca minor 'Alba' (Small-leaved White Periwinkle)

The small leaved evergreen Vincas (Vinca minor) are available in several shades of blue white as above [pictured on website] and also a deep purple. There are also a few with variegated leaves - aureovariegata with golden blotched leaves probably the best. There are also one or two double-flowered cultivars available. (There are also the larger leaved Vincas - Vinca major). The periwinkles are great for groundcover flowering best on a sunny bank though also happy in part shade beneath trees and shrubs. They do not like the soil to be too dry so if planted on banks then ensure a supply of water in hot summers. They will spread well after establishment and can be restrained - to a certain extent - by cutting back in early spring. Propagation is easy. Either divide the mature plants or dig up rooted 'layers' in Autumn or Spring and plant into new position.

Trailing long stems covered with broad leaves. The stems will be of various lengths up to 24" (61 cm). Zones 7 to 10. Treat as an annual in cooler climates. Full sun to shade. Keep soil moist. Incorporate a slow release fertilizer like Osmocote into the soil prior to planting. Fertilize with a balanced fertilizer like 20-20-20 on a weekly basis if no slow release is added to the soil. Prune to shape if needed. It will keep on blooming for you with good water drying out between applications good food and plentiful sun at least 1/2 day but sheltered from the hot sun from noon to 4 PM.

There is a very popular variety which may very well be what you have:

Jekyll's White Common Periwinkle Vinca minor `Jekyll`s White` (V.m. `Gertrude Jekyll`)

Beautiful dense ground-hugging evergreen perennial displays profusion of snow white flowers. Terrific neat ground cover for flower beds; interplant with spring bulbs. Valuable on banks and steep slopes. Shade. Moderate grower to 6 to 8 inches tall spreading wider. Cutting grown.