How to store bulbs

Learn how to store bulbs for the winter with these easy steps

Storing bulbs is a common concern among first-time growers of such summer bloomers as tuberous begonias, calla lilies, canna lilies, dahlias and gladiolus. With summer winding down and cooler temperatures on their way, it is time to bring heat-loving summer bulbs inside for a snug winter’s rest.

Left outside, exposed to winter’s wet, some bulbs, corms and tubers will rot into messy piles, never to offer beautiful blooms again. For these, it is essential to lift and prepare them for storage before winter.

Proper storage is the key to ensuring that your bulbs will survive the winter. Whether you are storing bulbs, corms, rhizomes or tubers, follow these steps.

How to store bulbs in 7 steps

Step 1: When the foliage has become quite yellow, gently dig up the plant with a spading fork. Be careful not to damage or cut the bulb. Any damaged or broken bits should be discarded. While many experts suggest you separate your bulbs in fall; I prefer to store the clump whole and wait until spring to divide just before planting.

Step 2: Gently brush off any soil from the base and give it a soft rinse. Hang the plants by the foliage in a well-ventilated, dark space for one week. The bulbs will absorb the moisture they need from the leaves and become dormant. Cut off the foliage.

Step 3: Inspect the clump for signs of disease or pests. Toss out anything infected, soft or mouldy. Store only large, firm pieces.

Step 4: Dust the bulb with sulphur to prevent mildew from setting in during storage. Sulphur dust is a safe fungicide and miticide. It helps control black spot, powdery mildew, rust, scab and mites on vegetables, fruit, flowers and bulbs. It can be dusted on or can be mixed with water and applied as a spray. This is an effective product for many problems, so be sure to keep it on hand in your garden shed.

Step 5: Fill a container (such as a terra cotta pot, plastic plant flat, cardboard box or bulb tray) with peat moss or vermiculite and set the bulbs in. Proper ventilation is critical, so store the bulbs in a single layer. Label the containers with the plant names. The peat moss should be barely moist for begonia and calla, and dry for dahlia and canna. Gladiolus store well in old clean onion bags.

Step 6: Store in a dark, cool, dry area. The ideal temperature is 13°C (55°F). A cool garage, basement or shed works well.

Step 7: Check your bulbs once a month to ensure that no mildew, disease or mice have invaded the containers.

Replant indoors four weeks prior to the last frost. For outdoor planting, wait until after you are sure the last frost has passed and the soil is above 4°C (39°F). They may look shrivelled and dehydrated, but have faith – they will bounce back and be lush green in no time!