1 - Gladiolus plants are not common garden plants in New Mexico, but if their requirements are met, may be grown successfully.

Yard and Garden November 23, 2013

Q.

I planted a lot of glad bulbs in the spring of 2012 and had such a wonderful expanse of color that I was thrilled. They were planted in a protected location, against a south-facing stucco wall, with some protection on the east and west, as well. I planted more in the spring of 2013 and got only about six blossoms altogether.

I want to assure that I have glads blooming in the spring of 2014. Do I need to dig them up and dry them and plant them again, or due to their protected location, can I count on their blooming again? Some people have told me I do not need to dig them up, that it was because of our strange 2013 spring that I got so few blossoms. The watering system on a timer has not been changed since first planting.

Do you have any advice for me?

Betty H.

Albuquerque

A.

Gladiolus plants are not common in Albuquerque gardens, but as you have seen they will grow and bloom here. They are listed hardy in USDA hardiness zone 8 and warmer. Albuquerque is in hardiness zone 7, one zone too cold. However, the site you described is probably a warm microclimate that will allow the gladiolus corms to overwinter without freezing in most winters. Loose organic mulch, such as pine needles or straw, may be helpful in maintaining constant soil temperatures in the winter. The mulch may also help maintain soil moisture and moderate soil temperatures in the summer as well.

The spring of 2013 was extremely dry and that could have contributed to the poor performance of your gladiolus. However, since you described "protection" to the east and west, I wonder if they are getting enough sunlight. They need at least 4 to 8 hours of sunlight each day. Reflected light from nearby walls may help and the afternoon shade is good. Never the less, adequate sunlight is a requirement for good growth and reblooming.

The bulbs should be planted deeply (4-6 inches) in a well prepared soil with adequate nutrients and moisture holding capacity. If they are not planted deeply enough, that could contribute to poor performance. Drying will have an even greater impact on plant growth and flowering. You mentioned an irrigation system, so I assume you were preventing the plants from excessive drying. Even during the winter, some moisture is needed, so do not let the plants dry excessively during the winter. On the other hand, too much constant moisture can also cause problems by favoring diseases. The soil should have adequate organic matter to help maintain a constant moisture level in the location you described. Organic soil amendments will also help lower the soil pH which will help in New Mexico. Your described location will be quite hot in the summer. Organic mulch will help moderate soil temperatures as well as conserve moisture.

After flowering, let the foliage die back naturally and slowly so that the corms are allowed to store adequate food for good growth and flowering next year. If you cut the leaves off too early, the corms cannot store enough food for the next year. Every 3 to 5 years clumps should be divided to maintain the vigor and health of individual plants. This is also a good time to add organic amendments and nutrients to the soil. A soil test will be helpful at this time to determine which nutrients are needed. Phosphorus is often a limiting nutrient in flowering plants.

Remember, our windy conditions may require staking of individual plants. Your protected location may help, but if the plants begin to fall, you can stake them to keep the flower stalks upright.

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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