Gladiolus Bulbs

Gladiolus / Dahlia / Lily Planting Guide
Gladiolus / Dahlia / Lily Receiving Guide

Among the most striking of the flowers that bloom from bulbs, gladiolus are best known and most often grown for cut flowers. You will find that our large corm sizes produce stronger plants and larger flowers than the so-called ‘landscape’ (smaller) bulb sizes often offered in the trade.

Shipping Information

Your gladiolus corms will be shipped to you directly from our grower via UPS (Sorry, we cannot ship to Alaska, Hawaii or Puerto Rico). We will begin shipping starting early May. Products ship Monday–Thursday for delivery by the weekend. For later ship dates call us to place your order. Planting instructions will be included with your shipment.

Gladiolus Planting Tips

Receiving

Gladiolus corms are shipped dormant. Do not be alarmed if they appear dry upon arrival. Occasionally growth with slightly yellowing plant tips will occur and is normal. A common issue for storing corms is related to fungal growth, which occurs with high moisture and humidity. Avoid fungal issues by unboxing immediately and providing adequate ventilation.

Open the box immediately upon receipt to provide air flow. Store in a cool, dry, well-ventilated area until they can be planted (not in a cooler). Planting as soon as possible is ideal. Outdoor planting is recommended after the last spring frost.

Growing Tips

Gladiolus produce beautiful cut flowers in late summer and may be grown in well-drained soil in a sunny location. The addition of a complete fertilizer such as “5-10-5” (at the rate of 3 to 5 pounds per 100 ft. of row) is beneficial, however do not place it in direct contact with the corms. They may be planted directly outdoors as soon as danger of frost is past, and successive plantings may be made to lengthen the flowering season. Space them about 4 inches apart in rows about 18 to 30 inches apart for easy cultivation. Plant 4 inches deep in heavy soil and 5 inches deep in lighter soil, covering the corms with 2 inches of soil at first, gradually filling in the trench as the plants grow. When cutting the flower spikes, 4 or 5 leaves should be cut to make food for new “cormels” (small corms). Use a sharp knife and a downward cutting stroke to avoid loosening of the corm. Beginning with the 3-4 leaf stage, deep watering is recommended at least once per week, unless there is an inch of rain.

Succession Planting

For blooms all summer, succession plant every 14 days with the last planting 90 days before your average first frost.

Insects/Diseases

Our corms have not been treated for insect or disease infestation (after field digging in the production area) and may be treated before planting if desired. Please check with a local source for a “gladiolus dust.” (combination of insecticide and fungicide).

Spray Program Recommendation

After planting, we recommend a spray program with an insecticide recommended for thrip control (see description below) at approximate two week intervals during the growing season. Unless a regular spray program is maintained, insect infestation can readily occur on gladiolus from pests from neighboring plants.

Thrips

Thrips are among the most common of insect pests occurring on gladiolus. These small insects bore within the leaves, causing silvery streaks on the leaves. The leaves then turn brown and die, due to the loss of life-sustaining sap. Flowers may not form, or if they do, may be deformed, and discolored with whitish streaks and flecks. Other Insects Aphids, tarnished plant bugs and red spiders are other insects that sometimes infest gladiolus.