As a gladiolus corm, I am the heart of the plant, a swollen underground stem packed with the energy needed to burst into life each spring. However, my tropical ancestry means I am vulnerable to the freezing, wet conditions of a cold winter left in the ground. To ensure I can perform for you again next year, a specific sequence of care is required. Here is my perspective on the process.
My growth cycle is dictated by the sun. After my glorious summer bloom, my priority is to gather as much solar energy as possible through my sword-like leaves. This energy is transported down to my core, where I begin to swell and develop a new corm on top of the old one, along with smaller cormels. You must be patient. Do not cut my foliage back immediately after flowering. Wait until the leaves have turned a distinct yellow or brown, typically after the first light frost has blackened them. This is my signal that I have completed my photosynthetic work and am entering dormancy. Lifting me while my leaves are still green starves me of this essential energy transfer, leaving me weak and unlikely to survive storage.
When the foliage has died back, carefully insert a garden fork or spade well away from my base to avoid spearing or slicing me. Gently lift the entire clump from the soil. Shake off the loose dirt, but be gentle; my new outer tunic is delicate. Now, you must make a critical decision. Some gardeners recommend leaving the foliage attached for a week or two to allow further drying in a warm, well-ventilated place like a garage. Others suggest cutting the stems back to about an inch (2.5 cm) above my crown immediately. Either way, the goal is to begin the curing process, allowing my outer layers to dry and harden, which seals out moisture and rot-causing pathogens.
Once the remnants of the stem are dry and brittle, it is time to separate us. You will find the shriveled, flattened remains of the old mother corm at my base. Gently twist and pull it away; it should detach easily. Discard it. Also, you can remove the small, round cormels that have formed around my base—these are my children, which can be grown into flowering-sized corms over a couple of seasons. Now, inspect me carefully. Any corm that feels soft, squishy, shows signs of rot, or has obvious holes from pests should be discarded without mercy. Only store the firm, healthy corms, as one rotten one can jeopardize the entire collection.
My dormancy requires a specific environment to mimic a dry, mild winter. After curing and cleaning, I need a medium that will maintain a slight humidity level to prevent me from desiccating into a hard, useless pebble, while also allowing air circulation. Do not seal me in an airtight plastic bag; this will encourage mold. Instead, place me in a breathable container. Ideal options include paper bags, mesh onion bags, or cardboard boxes with ventilation holes. You can nestle me in a loose, dry medium like peat moss, vermiculite, or wood shavings. The single most important factors are consistent coolness and darkness. A temperature range of 35-45°F (2-7°C) is perfect. An unheated basement, a cool garage (that won't freeze), or a ventilated crawl space are excellent choices. Check on me periodically through the winter; if I show signs of shriveling, the air might be too dry, and if I feel damp, more ventilation is needed.
About a month before your last expected spring frost, you can bring me out of storage. Inspect me again, discarding any that did not survive. The return of warmer temperatures and light will signal the end of my dormancy. You may even see small shoots beginning to swell at my crown. This is the time for me to be replanted into the warm soil, where I will draw upon the stored energy within my flesh to begin the magnificent cycle anew.
