Hi Gene
Gladioli are hardy wherever the soil does not freeze deeply in winter, generally from
zone 8 - 10. Here in
zone 3 I have to dig them up, but yours can be left in the ground. The bulbs can be covered with a thick, loose mulch or planted near a warm wall to extend hardiness up to
zone 6.
Gladioli grow from corms, and the corms should be planted 4 -6 inches deep in a full sun location.
plant the corms in groups or rows. Support may have to be given to tall varieties.
plant them when all danger of frost is past. Cormlets will form at the base and alongside the corm. The cormlets can be separated from the parent corm in the fall or when the foliage yellows. Store the corms over winter, and
plant them the following
spring. Soak the cormlets before planting to help speed sprouting. Cormlets will grow to flowering size in 2-3 years.
Fertilizing is recommended for bulbs that are left in the ground for many years. Use a commercial bulb food on these bulbs, raking it lightly into the soil during fall cultivation. The foliage should be allowed to ripen or yellow naturally before being removed as this allows the bulb to store nutrients needed for future growth and blooming. Gladioli will produce larger
flowers if they are fed with a liquid fertilizer every 3 weeks after the buds form and until they open. Remove the blooms as they wither. The bulbs will exhaust themselves if the
seeds set.
Good luck
Barb
barbsblooms@shaw.ca
