Planting Guide - Gladiolus Bulbs
Gladiolus (from Latin, the diminutive of gladius, a sword) is a genus of perennial bulbous flowering plants in the iris family – Glads actually do not grow from bulbs but from “corm” – a closely related cousin. Sometimes called the sword lily, the most widely-used English common name for these plants is simply gladiolus (plural gladioli, gladioluses or sometimes gladiolas). The Gladiolus flower signifies remembrance. It also expresses infatuation, telling the receiver that he or she pierces the heart.
Gladiolus in Your Garden
Gladiolus plants are attractive, perennial herbs and semi-hardy in temperate climates. All gladioli are easy to grow, colorful and make great cut flowers, hence their popularity. With very little work needed, your Gladiolus will burst into bloom in August, adorning your garden with bright, colorful, tall flowers that will make for a wonderful addition to any scheme.
When & How to Plant Gladiolus Bulbs
Plant your Gladiolus bulbs/corms in the spring, as soon as the soil has warmed up in March or April. Loosen the soil to about 12 to 15 inches deep and add in a 2-4 inch layer of compost.
While they prefer full sun, Gladiolus will still grow well in partial shade. Gladiolus plants prefer rich, soft soil, and plenty of water. If the soil is poor, add a little fertilizer to help stimulate growth.
Set your corms in their planting locations with the pointed end facing up. Cover with soil and press firmly. If planting tall varieties, set your stakes now, taking care not to pierce the corms. Water thoroughly.
The Gladiolus bulbs (or corm) can be grown in rows or bunches. They will tolerate a little crowding but will grow bigger if spaced out. We recommend planting the bulbs 6-8 inches deep - secured deep in the ground, you are less likely to need a stake. Plant them about 3-6 inches apart. If you have bought quite a few, don't plant them all at once. Stagger their planting times and you will get a better succession of flowers.
Add mulch to help retain water, and to keep the weeds down. Gladioli need plenty of water to flower well. On well-drained poorer soil, extra watering will be required. Rule of thumb is if the area receives less than 1 inch of rain a week, then water your plants regularly throughout the summer. Soil should remain moist throughout the growing period.
Once planted, your gladiolus should grow well with little attention, provided the soil remains moist but not water logged. As they bloom, remove the faded and dying flowers to ensure continuous growth. Gladiolus is a great cut flower, so be sure to cut and enjoy inside too!
Preparing for Next Season
If you live in a temperate region, mulch the bulbs deeply with 2.5 inches of compost to give them an insulating duvet over their heads in late autumn.
In colder regions, grow them in a sheltered spot and lift them for the winter when the leaves turn yellow-brown and before the first frost. Lift them and cut the stem with one inch above the corm. Dry them out in a warm and airy location for a couple of weeks, cleaning off excess soil. Remove (by snapping off) and discard the oldest bottom corms from the base of the new corms. Store the new corms in open paper bags, cloth bags, wooden trays, screens, or old onion sacks – any container that receives good air circulation. These must be kept dry and cold (but frost-free) until they are replanted, a cool basement is recommended. You can dig and divide the clumps every few years to select the best corms for replanting. Replant your stored corms the following spring for summer blooms!