February 19, 2011

1 - An old concrete lily pond with the bottom remove can become a large container garden.

Yard and Garden - February 19, 2011


I found the NMSU web site just now, and hope you can help us.

In the Southeast corner of our back yard, which is medium shady, we had a waterfall/pond, and have recently broken up the concrete bottom of the pond and filled it in with soil, and a few bags of top soil. We plan to add some mushroom compost, and possibly some worm compost.

Can you help us choose either plants or herbs that might thrive in such an environment? We prefer perennials, and like drought tolerant plants as much as possible.

- Bill d'E.



I am assuming you left the sides of the pond, and perhaps the broken-up bottom, so this is still a "sunken container garden". As such it will hold water and confine roots unlike the open garden. If you did remove the bottom, the sides still limit root growth as if the plants were in a large container. Since it is broken, and perhaps removed, drainage should be adequate to prevent water-logging of the roots of the plants. Addition of compost increases the water-holding capacity of the soil. The "top soil" may be just another kind of compost if it was in a bag. It will also increase soil water-holding capacity. Some arid land adapted plants (sometimes called drought tolerant plants) will not do well under conditions of high organic matter, and some will.

Some plants to consider are irises (water efficient because they are dormant in mid-summer). The most arid adapted irises are those called arils or aril-bred irises. They will bloom early in the spring and some will bloom again in the autumn. They will need to be divided and thinned every 3 to 4 years.

Daylilies are another good plant to consider. By choosing varieties carefully, you can have a long season of flowers through the summer. These will also need to be divided and thinned every few years.

Hardy crepe myrtles may work in that location, but a winter like we just experienced may kill them, or freeze them to the ground. They will bloom in the summer. Some newer varieties have been bred to have increased winter hardiness, look for these. Butterfly bush shrubs are another good option and quite hardy. They also bloom in the summer and have a nice fragrance. Texas (or red) yucca should grow well in this setting. They are very well adapted to dry environments and produce attractive arches of red or yellow flowers. They are not tall yuccas like the Palm yucca, but are very attractive.

Dwarf plumbago, Rocky Mountain (or prairie) zinnias are good low growing ground cover perennials for this location. The dwarf plumbago produces blue flowers through the summer. Their leaves turn reddish in the fall before becoming a dark, chocolate brown through the winter. The Rocky Mountain zinnia produces a large quantity of yellow flowers in the late spring and scattered yellow flowers during the summer. They have fine textured leaves that turn tan in the winter as opposed to the dwarf plumbago's coarse textured leaves which turn dark brown in the winter. The dwarf plumbago will be better adapted to high levels of organic matter and moisture while the Rocky Mountain zinnia will do better if kept quite dry.

These are only a few of the possible plants to use in this setting. The list of potential plants is very extensive. I did not mention ornamental grasses that would be attractive in this setting or many other perennials. I did not mention any annuals. These can be used to fill less colorful spots when the perennials are just pretty masses of green. Visit some nurseries and peruse catalogs to find plants that appeal to your personal aesthetic preferences.

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.


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