Which plants need lifting?

Not every bulb or tuber needs to come out of the ground in November. Hardy daffodils, crocuses, many alliums and most established spring bulbs stay where they are. Tender plants such as dahlias, cannas and some gladioli are different: prolonged cold and wet soil can damage their storage organs. Whether to lift them depends on the species, the drainage of your soil and the severity of local winters. In sheltered areas some gardeners successfully leave dahlias in well-drained ground beneath protection, but lifting offers more control where winters are wet or cold.

Wait for the right moment

Dahlia foliage is often blackened by the first frost, signalling that top growth is finished. That is a common cue to prepare for lifting, though you should not wait if a severe freeze is forecast and the tubers are vulnerable. Cannas should be brought into frost-free conditions before hard cold. Gladioli grown from less hardy corms are usually lifted after foliage begins to yellow and die back. Always identify the plant before following a generic storage routine; different species tolerate different moisture levels.

Tools and preparation

Choose a dry day if possible and have a garden fork, secateurs, labels and ventilated trays ready. Label plants before stems disappear, especially if you grow several colours or named varieties. Check that the intended storage space is cool, frost-free and not dripping with condensation. A garage or shed may work if it stays above freezing; an unheated outbuilding that freezes solid is not automatically safe. Keep storage material clean and separate any obviously diseased specimens.

How to lift dahlia tubers

Cut back the top growth, leaving a short length of stem to help handle and identify the clump. Insert a fork well away from the crown and work around the plant rather than levering against the tubers. Lift gently because dahlia necks can snap. Shake off loose soil and inspect the clump. Do not tug it by the stems. Allow surface moisture to dry in a sheltered place before packing, and avoid leaving lifted tubers exposed to frost overnight.

Storing dahlias without rot or shrivelling

Dahlia tubers need a balance: too wet and they rot, too dry and they shrivel. Place dry-surfaced clumps in shallow boxes with a suitable loose packing material if your storage environment requires it. Some gardeners use barely moist compost, vermiculite or wood shavings; the aim is to prevent excessive drying, not to keep the tubers wet. Check the boxes regularly and remove any rotting tissue or badly affected tubers. Never seal wet tubers in an airtight plastic bag.

Lifting and storing cannas

Cannas grow from rhizomes and usually prefer not to be dried to the same extent as gladiolus corms. Lift carefully, trim foliage and allow excess surface moisture to drain away. Store in a frost-free place in trays or pots with a little barely moist compost, checking that rhizomes do not become sodden. If you grow cannas in containers, moving the whole pot into frost-free storage can be simpler than disturbing the rhizomes. Reduce watering sharply while the plant is dormant.

Gladioli and other corms

Once the foliage has matured and begun to yellow, lift tender gladiolus corms carefully. Let them dry in a well-ventilated, frost-free place, then remove loose soil and old papery material when it comes away easily. Store sound corms in labelled paper bags, nets or shallow trays with good airflow. Discard soft, mouldy or badly damaged corms. Small cormels can be kept if you want to grow them on, though they may take several seasons to flower.

Where to keep the boxes

A dark or shaded, cool, frost-free space is generally useful, but temperature and humidity requirements differ between plants. Keep boxes off cold concrete floors and away from heaters that cause rapid drying. Check for mice and other pests, particularly in sheds. Good airflow matters more than making the storage space perfectly airtight. Use a simple thermometer to learn how cold the room gets during a frosty night; guessing can cost you an entire collection.

Monthly checks through winter

Set a reminder to inspect stored plants every few weeks. Look for soft patches, mould, shrivelling and unwanted early shoots. Remove rotting specimens promptly so they do not affect their neighbours. If dahlias are drying badly, adjust the packing material slightly rather than soaking the whole box. If condensation is building, improve ventilation and investigate whether the material was stored too wet. Keep labels legible and update your list of varieties before spring.

When to restart growth

As spring approaches, dahlias and cannas can be potted up in suitable compost under frost-free cover to encourage early growth. Do not put tender new shoots outdoors just because a few warm days arrive. Harden plants off gradually after the risk of frost has passed in your area. Gladiolus corms can be planted at the appropriate spring time once the soil is warming. Inspect stored material one last time before potting, and discard anything that has rotted beyond recovery.

Frequently asked questions

Can I leave dahlias in the ground? Sometimes, in mild, well-drained gardens with suitable protection, but winter wet and hard frost make it a gamble. Should I wash tubers? Practices vary; if you wash them, dry surfaces thoroughly before storage. Can I keep bulbs in a warm house? A heated room often encourages drying or premature growth and is usually unsuitable. Do all gladioli need lifting? Hardiness varies by type, so check the exact variety rather than assuming all behave alike.

Final advice

The biggest advantage of lifting tender plants is being able to inspect them. Label carefully, store cool and frost-free, and check regularly. Those small habits make it far more likely that your favourite dahlias, cannas and gladioli will be ready for another season.

Know which plants really need winter storage

Dahlias are usually the first plants gardeners think of when lifting tender underground parts, but they are tubers rather than true bulbs. Gladioli grow from corms, while cannas grow from rhizomes. These distinctions matter because each stores and dries a little differently. In milder, well-drained gardens, some gardeners successfully leave dahlias in the ground beneath protection; in colder or wet sites, lifting is safer. Gladioli grown from tender varieties are generally lifted after foliage dies back. Cannas are often lifted or moved under cover before hard frost. Check the particular cultivar and local conditions rather than treating every underground plant alike.

Lift without damaging the storage organs

Choose a dry day when soil is workable. Begin digging some distance from the stem and ease a fork underneath the root mass, lifting slowly rather than pulling by the stems. Shake or brush off loose soil without tearing the fleshy storage organs. Label each clump immediately with its variety and flower colour, as dormant tubers can be surprisingly difficult to identify. Cut back top growth according to the plant's needs, keeping enough stem to handle or identify the clump. Inspect for cuts, soft patches and insect damage. Small wounds can sometimes dry and heal, but badly rotted material should not be put into storage with healthy stock.

Dry and pack the harvest carefully

Let lifted material surface-dry in a frost-free, airy place out of direct strong heat. The aim is to remove excess surface moisture, not shrivel the plant. Dahlias generally need cool, frost-free storage with enough humidity to prevent severe drying, while gladiolus corms are usually cured more thoroughly before dry storage. Cannas must not be allowed to freeze and should not be left bone dry for long periods. Use labelled trays, boxes or suitable packing material so different varieties stay separate. Do not seal damp tubers in airtight plastic, which can encourage mould. A shed that freezes overnight is not a safe storage place simply because it has a roof.

Inspect stored bulbs and tubers throughout winter

Check your stores every few weeks. Remove anything becoming soft, mouldy or foul-smelling before rot spreads to neighbouring pieces. If dahlia tubers are shrivelling badly, review the temperature, airflow and moisture of the packing material rather than soaking them indiscriminately. If condensation is forming inside a container, increase ventilation and inspect for decay. Keep stored plants away from rodents, which can damage some bulbs and tubers. Use sturdy mesh or lidded ventilated crates if necessary. Record losses and the storage conditions so you can adjust your method next winter. Good storage is an ongoing process, not a job finished on lifting day.

Restart growth safely in spring

When frost risk is easing, inspect each stored clump and discard any parts that have rotted. Pot dahlias into compost under frost-free cover to encourage shoots before planting outside after the last frost. Cannas can also be started warm under cover for an earlier display. Gladiolus corms are generally planted into suitable soil once conditions are warming, following the depth recommended for their size. Harden off plants raised under cover before moving them into exposed beds. Do not rush tender growth outdoors because of one mild weekend in April. A few extra weeks of protection can save months of careful storage and propagation.