How To Store Bulbs Until Planting

Learning how to store bulbs until planting is a key skill for any gardener. Properly storing bulbs until planting ensures they remain healthy and viable for the next growing season. This guide will walk you through the entire process, from digging them up to tucking them away, so you can enjoy beautiful blooms year after year.

Storing bulbs correctly is not complicated, but it does require attention to detail. The main goals are to keep them dry, cool, and safe from pests. When done right, you preserve the energy and life within the bulb, setting the stage for a spectacular display. We will cover everything you need to know, starting with the initial steps of preparation.

Knowing Which Bulbs Need Lifting

Not all bulbs need to be dug up and stored. Many are quite hardy and can stay in the ground through winter. Knowing which ones to lift saves you time and effort.

Tender Bulbs: These cannot survive freezing temperatures in the soil. They must be lifted and stored indoors. Examples include dahlias, gladiolus, cannas, caladiums, and tuberous begonias.
Hardy Bulbs: These are built to withstand cold winters and typically do not need lifting. Examples include tulips, daffodils, crocus, hyacinths, and alliums. They are usually planted in the fall for spring blooms.
Special Cases: In regions with extremely wet winters, even some hardy bulbs may benefit from lifting to prevent rot. If your soil does not drain well, consider storing them.

The Right Time To Dig Up Your Bulbs

Timing is critical. Dig too early, and the bulbs won’t have stored enough energy for next year. Dig too late, and you risk frost damage or losing them in the ground.

After Foliage Dies Back: The best signal is the plant itself. Wait until the foliage has turned yellow or brown and died back naturally. This process allows the plant to photosynthesize and send energy down to the bulb for storage.
Before the First Hard Frost: For tender bulbs, you must dig them up before the first hard freeze blackens the foliage. A light frost is often okay, but don’t wait too long.
Seasonal Guide: Generally, this means digging up summer-blooming tender bulbs in the fall, after the first frost warnings. Spring-blooming hardy bulbs are usually dug (if needed) in late summer, once their foliage has completely faded.

Step-By-Step Guide To Digging And Cleaning

Careful handling during the dig prevents damage that can lead to rot later. Follow these steps for a successful harvest.

Gather Your Tools: You will need a garden fork or spade, gardening gloves, a soft brush, and a tray or basket.
Loosen the Soil: Insert your fork into the soil several inches away from the plant’s base. Gently lever the soil to loosen it and lift the clump of bulbs. Avoid stabbing the fork directly into the cluster.
Lift Gently: Carefully lift the clump and shake off excess soil. Use your hands to seperate the bulbs from the main clump, being gentle to avoid breaking or bruising them.
Initial Cleaning: Brush off the majority of the soil with your hands or a soft brush. Do not wash bulbs with water unless they are extremely muddy; moisture at this stage can encourage mold. If you must rinse, let them dry completely afterward.
Trim Foliage: Using clean pruners, cut off the dead foliage, leaving about an inch or two above the bulb. For bulbs like dahlias, you will cut the stems back to a few inches above the tuber clump.

Curing Bulbs For Storage

Curing is a drying period that prepares the bulb for long-term storage. It toughens the outer skin and heals any minor wounds.

The Process: Place your cleaned bulbs in a single layer on a screen, rack, or in a flat cardboard box. Do not pile them on top of each other.
Ideal Location: Choose a warm, dry, well-ventilated, and shaded spot. A garage, garden shed, or covered porch often works well. Avoid direct sunlight, which can scald the bulbs.
Duration: Let them cure for about one to three weeks. The outer layers should feel dry and papery, similar to an onion skin. Thicker tubers, like dahlias, may need closer to a week. You’ll know they’re ready when no moisture is felt at the stem base.

Inspecting And Sorting Your Bulbs

Before storing, you must check each bulb’s health. One rotten bulb can spoil the entire batch.

Visual Inspection: Look for any signs of damage, soft spots, mold, or obvious disease. The bulb should feel firm and heavy for its size.
The Squeeze Test: Gently squeeze each bulb. Discard any that feel soft, mushy, or lightweight. These are likely rotten or diseased and will not recover.
Sort by Size and Type: Sort your bulbs into categories by type and size. Larger bulbs often produce stronger blooms. Storing like with like makes planting easier next season.
Dusting (Optional): Some gardeners lightly dust bulbs with a fungicide powder like sulfur to prevent fungal issues. This is a personal choice but can be beneficial in humid climates.

Choosing The Best Storage Materials

The right container and packing material make all the difference. They regulate moisture and allow for air circulation.

Containers: Use breathable containers. Cardboard boxes, paper bags, mesh bags (like onion bags), wooden crates, or even old nylon stockings are excellent choices. Avoid sealed plastic bags or airtight containers, as they trap moisture and cause rot.
Packing Materials: Separate layers of bulbs with dry packing material. Good options include peat moss, vermiculite, perlite, wood shavings, or dry sand. The material should be just barely moist, if at all. You can also use crumpled newspaper.
Labeling: Always label your containers! Include the bulb type, variety, color, and the date you stored them. It’s easy to forget by spring.

Ideal Storage Conditions

Creating the right environment is the final, crucial step. The goal is to mimic the bulb’s natural dormant period.

Temperature: Most bulbs need a cool, consistent temperature. The ideal range is between 40°F and 55°F (4°C and 13°C). A basement, unheated garage, or cool closet often provides these conditions. Avoid places where temperatures fluctuate wildly or drop below freezing.
Humidity: Humidity should be moderate, around 50-70%. Too dry, and the bulbs may desiccate and shrivel. Too damp, and they will mold or sprout prematurely. Your packing material helps buffer humidity levels.
Darkness: Store bulbs in complete darkness. Light can signal them to start growing. Ensure your storage area is dark or that your containers block out light.
Airflow: Good ventilation prevents stagnant, moist air from settling around the bulbs. Do not seal the containers tightly; allow some air exchange.

Monitoring Bulbs During Storage

Don’t just forget about your bulbs until spring. Check on them periodically to catch any problems early.

Schedule Monthly Checks: Set a reminder to inspect your stored bulbs about once a month.
What to Look For: Look for signs of mold, shriveling, or premature sprouting. Check for any soft or rotten bulbs and remove them immediately.
Adjusting Conditions: If bulbs are shriveling, the storage area might be too dry. You can very slightly dampen the packing material. If you see mold or condensation, the area is too humid. Move the bulbs to a drier location and replace the packing material with something fresher and drier.
Pest Patrol: Look for signs of mice or insects. Rodents find some bulbs quite tasty. Ensure your storage area is secure.

Special Considerations For Different Bulb Types

While the general principles apply, some bulbs have specific needs.

Storing Tender Bulbs Like Dahlias And Gladiolus

Dahlias and gladiolus corms need careful handling. After curing, store dahlia tubers in slightly moist peat moss or vermiculite to prevent shriveling. Gladiolus corms should be completely dry and can be stored in paper bags. Both prefer temperatures around 40-50°F.

Storing Summer Bulbs Like Cannas And Caladiums

Canna rhizomes are large and can be stored in cardboard boxes with peat moss. Caladiums are more delicate; store them in a warmer spot, around 60°F, as they are tropical plants and can be damaged by very cold storage conditions.

Storing Spring Bulbs Like Tulips And Daffodils

If you are storing hardy spring bulbs (which is less common), ensure they are completely dry. Store them in mesh bags in a cool, dark place. They often require a period of cold to bloom, so if you’re storing them for fall planting, a refrigerator drawer (away from fruit) can work, but monitor for moisture.

Preparing Stored Bulbs For Planting

When the correct planting season arrives, you need to wake your bulbs up properly.

Inspect Again: Conduct a final inspection. Discard any bulbs that did not survive storage.
Rehydrate if Necessary: If bulbs appear slightly shriveled, you can soak them in lukewarm water for a few hours before planting to rehydrate them. Do not do this for bulbs that appear plump and healthy.
Pre-Sprouting (Optional): For a head start, you can place bulbs in a tray with moist potting mix a few weeks before outdoor planting time. Keep them in a cool, bright location to encourage root growth.
Plant at the Right Depth: Follow specific planting depth instructions for each bulb type, usually two to three times the height of the bulb itself.

Common Storage Mistakes To Avoid

Being aware of these common errors will increase your success rate dramatically.

Storing While Damp: This is the number one cause of rot. Never store bulbs that are not fully cured and dry.
Using Airtight Containers: Plastic bags or sealed totes trap ethylene gas and moisture, leading to mold and decay.
Ignoring Temperature: Storing bulbs in a warm house (like a heated basement) will cause them to use up their energy reserves or sprout far too early.
Forgetting to Label: You might think you’ll remember, but it’s easy to mix up varieties. Always label.
Skipping Monthly Checks: A single rotten bulb can quickly spread fungus to others. Regular monitoring is essential.

FAQ Section

Here are answers to some frequently asked questions about storing bulbs.

How long can you store bulbs before planting?

Most bulbs can be stored successfully for several months, typically from when they are dug up in the fall until they are replanted in the spring. The exact duration depends on the bulb type and storage conditions. Tender summer bulbs are meant for this cycle, while hardy spring bulbs are best planted in the fall shortly after purchase.

Can you store bulbs in the refrigerator?

Yes, but with caution. A refrigerator can provide the cool, consistent temperature some bulbs need. However, you must keep them away from fruits like apples, which release ethylene gas that can damage or kill the flower inside the bulb. Use a ventilated paper bag and place them in a dedicated drawer, if possible.

What is the best way to store flower bulbs for the winter?

The best way is to ensure they are dry, cured, and placed in breathable containers with dry packing material like peat moss. Then, store those containers in a cool, dark, and well-ventilated location with moderate humidity, checking on them periodically throughout the winter months.

Why are my stored bulbs molding?

Mold indicates excessive moisture. This could be because the bulbs were not fully dry before storage, the packing material was damp, the storage area is too humid, or the container does not allow for enough air flow. Remove molded bulbs immediately, and let the remaining ones air out. Replace the packing material with something completely dry.

Is it better to store bulbs in peat moss or vermiculite?

Both are excellent choices. Peat moss is acidic and has natural antifungal properties, but it can be very dry and may need slight, careful moistening for some bulbs. Vermiculite is neutral, sterile, and holds a bit of moisture well. The choice is personal; the key is to ensure whichever you use is not wet when you pack the bulbs.