General

Gladiolus are probably one of the oldest cut flowers around. They can generally be grown in most climatic zones as an outside crop. Due to their size and cost, Gladiolus are generally not forced in a greenhouse environment. However, they can be grown in plastic or glass houses. Keep in mind that Gladiolus require a lot of light and space in order to develop into a healthy mature plant. The following problems can occur with greenhouse grown Gladiolus: light deficiency during the winter months and crop temperatures that are too high during the summer.

Growing Area and Planting

Gladiolus should be planted outside in early spring as soon as the danger of frost is gone. For climates with no frost, Gladiolus can be planted year round, except for areas where the summer temperature is too high for the production of quality bulbs.

Timing

The optimum temperature for growing Gladiolus is between 50 degrees Fahrenheit and 80 degrees Fahrenheit. Gladiolus can tolerate higher temperatures, but in this case only certain varieties are suitable. Depending on the average temperatures during it’s growing season and the variety that you use it can take as little as 60 days and up to as long as 120 days to cultivate Gladiolus. The following chart will give you an indication on it’s production time span.

Average Cultivation Temperature Duration of Cultivation in Days

54 F 110-120 days

59 F 90-100 days

68 F 70-80 days

77 F 60-70 days

Soil Requirements and Watering

Gladiolus can be grown in all types of soil, providing that the structure and drainage of the soil is good. Bulbs should be planted in freshly steamed or fumigated soil with a pH of 6-6.5. Plant bulbs sufficiently deep (5-6”) since the plants become top heavy at maturity. Plant the bulbs at least 2” apart in rows. It is recommended to dip bulbs in a fungicidal solution prior to planting. After planting cover your rows or beds with a mulch of pine needles, straw, etc. in order to maintain a consistent soil temperature and to keep the soil from drying out too quickly, especially during the summer months. Water thoroughly right after planting and keep the soil slightly moist until signs of vigorous growth are visible, then increase watering. Always irrigate in the morning, so the crop can dry during the day.

Fertilizing

Fertilizing can start as soon as the plants have established a healthy root system. Use approximately 2 lbs of 5-10-10 per 100 row feet as indicated below:

Before planting, as a side dressing about 1 month after planting, as a final side when

spikes are just visible

Cutting and Processing of Flowers

The flowers can be cut as soon as the bottom flower-bud of the spikes start coloring. After cutting, the flowers should be processed, stored and transported in an upright position, to keep the tops of the spikes from getting crooked. After harvest hydrate the flowers in water at room temperature for about two hours, then remove flowers from water and store dry in a cooler with a temperature of 35 F to 40 F.