Issue: March 24, 2007
Low-growing plants for New Mexico/Divide iris in late summer if possible
Low-growing plants for New Mexico
Question:
I want to plant some low growing evergreens and some type of flowering ground cover to help prevent erosion in a 5x20 ft. area. Are there some plants that will fit our climate?
Las Vegas N.M.
Answer:
There are several low growing evergreens that you may want to consider. Although I will discuss only evergreen plants, there are several low growing deciduous plants you could also consider; but, for the area that you described, perhaps one of these will be best for erosion control and beautification.
There are creeping junipers (Juniperus horizontalis cultivars) that you can plant here. Select female clones that produce the berry-like cones to avoid pollen allergies (if allergies are a concern). The junipers do not produce attractive flowers, but their all-season-green is attractive. Flowering bulbs may be planted with them to come up through the branches and provide spring color. In open spaces between the junipers various flowering annual plants or perennials may be planted to provide bright colors during the summer.
English ivy is a broadleaf evergreen that creeps (it will also climb walls and trees). It doesn't have showy flowers, but like the junipers it is attractive all year. Flowering bulbs, annuals, and perennials can be planted with this spreading vine to provide color while the vine protects the ground from erosion. It will need occasional pruning to keep it from spreading where you don't want it to grow.
A final choice in this short list (there are other possibilities) is the periwinkle vines (Vinca major and Vinca minor) may be the plants you want. These are creeping vines with broad dark green leaves that remain on the plant and retain their attractive green color in the winter. They produce beautiful blue flowers. A few periwinkle vines will eventually cover the whole area you described and may then require pruning each year to keep them in bounds. With their attractive flowers during the summer, dark green leaves year-round, and their ability to cover the soil to prevent erosion, these may be the plants you want.
There are others if this short list isn't adequate. However, a few of each of these plants will fill the area you described and help prevent erosion. I think only one of these types should be used in this area, unless the owner is willing to keep each one pruned out of the other. They will all eventually fill and overflow the area and require some pruning.
Divide iris in late summer if possible
Question:
I live in Edgewood and have some irises that need to be divided. I was told by a friend that I should divide them every 3 years. The last I divided them was 4 years ago. Should I divide them now or wait till Fall?
John C.
Answer:
You are correct that irises will do best if divided every few years. As the clumps of iris plants become dense, their flowering diminishes. New, smaller plants in freshly prepared soil will renew their flower production.
Late summer is the best time to divide them. That is the time when their summer dormancy is ending and they are preparing to produce new roots. Cut the rhizome (thick horizontal stem that creeps along the ground) so that a single "fan" of leaves remains with only a few inches of rhizome attached. Then put these new plants into the newly prepared iris bed. This soil should have been well loosened, with compost and a source of phosphorus (commercial phosphate fertilizer or colloidal phosphate rock) worked into the soil.
You can divide them now, if you wish, but that may prevent them from blooming this spring. However, if you can wait, they will then be able to reestablish themselves in the fall and bloom the following spring. You should not loose any blossoms, and by dividing them, you will maintain their health and increase the following years' blossom production.
Have you considered growing the reblooming irises? These are irises that bloom in the spring like the irises that are familiar to us, but then they often bloom again in the fall. By doubling the flowering season we increase our enjoyment of irises, but we create a dilemma. We must consider the fact that we may occasionally loose the flowers the first fall after dividing. Even if you loose flowers for one fall, the process of dividing increases their flowering in subsequent years just as it does in the once blooming irises.
<Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.
For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.
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