Quick Answers
Yes, you can save gladiolus bulbs and replant them the next year. Gladiolus are summer-blooming bulbs that go dormant in winter. After the foliage dies back in fall, you can dig up the bulbs, separate and store them over winter, and replant them in spring. This allows you to have flowers from the same bulbs year after year.
When to Dig Up the Bulbs
Gladiolus bulbs should be dug up after the foliage has died back in late fall or after the first frost. This is usually around 8-10 weeks after the gladiolus have finished flowering. Waiting until the foliage has fully dried allows the plant to move nutrients back into the bulb for next year’s growth. Digging too early can weaken the bulb.
Aim to dig up the bulbs before the ground freezes in winter. In areas with very cold winters, dig up the bulbs 6-8 weeks after flowering. In mild winter climates, you can wait 10-12 weeks after blooms are spent.
How to Dig Up and Store Gladiolus Bulbs
Follow these steps to successfully dig, cure, and store gladiolus bulbs:
Digging Up
– Use a garden fork or shovel to carefully lift the bulbs from the soil. Take care not to damage the bulbs.
– Lift the foliage and roots along with the bulbs. Do not pull or cut off foliage at this stage.
– Gently shake or rinse off excess soil from the roots and bulbs. Do not wash vigorously or soak the bulbs at this stage.
Curing
– Allow bulbs to cure for 1-2 weeks in a warm, dry spot out of direct sun. This allows the skin to properly seal over the wounds from digging.
– Lay the bulbs out in a single layer with foliage and stems attached.
– Ideal curing temperature is 70-75°F. Avoid excess heat over 85°F.
Cleaning and Storing
– Once cured, cut off the foliage 2 inches above the bulb. Roots may also be trimmed off.
– Clean off any remaining soil debris with a soft brush or cloth.
– Sort the bulbs by size. Discard any that are diseased or damaged.
– Place bulbs in paper or mesh bags. Plastic bags retain moisture and can lead to rotting.
– Store bulbs over winter in a cool, dry spot around 40-45°F. The lower 40s is ideal.
– Avoid excess moisture and humidity during storage to prevent mold and decay.
How to Prepare and Replant Bulbs
In early spring when ground thaws, unpack stored gladiolus bulbs and get them ready for replanting:
– Inspect bulbs and discard any that are soft, rotten, or show signs of disease. Healthy bulbs will be firm.
– Trim off any dried roots or foliage.
– Sort bulbs by size. This ensures uniform growth when planted.
– Soak bulbs in warm water 110°-120°F for 45-60 minutes before planting. This hydrates bulbs and stimulates root growth.
– Allow to dry before planting. Bulbs can be dusted with fungicide if desired.
– Plant the bulbs 4-6 inches deep and 6-8 inches apart in spring after the last frost.
– Cover with soil and water thoroughly after planting.
Tips for Reblooming Gladiolus
Follow proper growing conditions to ensure gladiolus bulbs rebloom successfully:
– Plant in full sun in well-draining soil enriched with compost or organic matter.
– Space the bulbs properly based on variety and tag plants for identification.
– Water 1-2 inches per week. Avoid overwatering, especially with heavy clay soils.
– Stake tall varieties to provide support once stems lengthen.
– Apply a balanced fertilizer when new growth emerges and again when buds form.
– Remove spent flowers but leave the foliage until it dies back naturally.
– Dig and cure bulbs promptly after foliage dies back in fall.
– Store cured bulbs properly over winter and replant the following spring.
Can All Gladiolus be Saved from Year to Year?
Most gladiolus varieties can be saved from year to year, but some hybrids may not rebloom well or come true to type. Heirloom varieties and species gladiolus are most likely to rebloom successfully when overwintered.
Gladiolus that rebloom reliably include:
– Gladiolus dalenii – small purple and yellow heirloom gladiolus
– Gladiolus nanus – dwarf gladiolus under 2 feet tall
– Gladiolus communis – common in perennial and cottage gardens
– Gladiolus primulinus – delicate yellow to orange shades
– Gladiolus murielae – known for reliable reblooming
Some hybrids worth trying to overwinter include:
– Jetfire
– Oscar
– Jester
– Blue Isle
– Purple Flora
Avoid saving weak, diseased bulbs or those that did not bloom well. Focus on replanting only your healthiest, best-performing bulbs each season.
Do Gladiolus Bulbs Multiply Each Year?
Yes, as gladiolus bulbs are replanted each year, they will naturally increase and multiply via offsets called cormels.
How Gladiolus Bulbs Multiply
– The main gladiolus bulb is called a corm. It generates new growth each year from the top while producing cormels from the bottom.
– Cormels are like miniature versions of the parent corm with their own growing points.
– As cormels mature over one or more seasons, they develop into full sized corms capable of flowering.
– A large flowering gladiolus corm may produce 3-6 or more cormels in a season.
Saving and Planting Cormels
– Dig cormels attached to the parent corm in fall and cure as normal.
– Store cormels over winter with the large corms.
– In spring, separate cormels and plant them in a nursery bed rather than in flower beds.
– Grow cormels for 1-2 years to reach flowering size before replanting in the garden.
This multiplication effect means you can generate many plants from just a few originally purchased bulbs!
Do Gladiolus Bloom True to Color from Bulbs?
Generally, gladiolus will bloom true to color from saved bulbs. However, there are a few exceptions:
– Some hybrids may revert back to parent colorings or take on different hues.
– Cormels from a prior year may not bloom true as they reach maturity.
– Viruses can affect bloom color in diseased bulbs.
– Extreme soil chemistry changes may subtly alter colors.
To ensure true colors each season:
– Save only healthy, vigorous bulbs after verifying bloom color.
– Plant heirloom varieties known for coming true.
– Grow cormels to maturity before introducing to flower beds.
– Maintain soil pH and nutrients at optimal levels.
– Remove diseased plants immediately to prevent virus spread.
With care, you can achieve reliably bright and beautiful gladiolus blooms that match the original bulb’s colors.
Do Gladiolus Get Bigger Each Year from the Same Bulb?
The gladiolus bulb or corm itself does not get dramatically bigger in size from one year to the next. However, as existing bulbs multiply into cormels and reach maturity over several seasons, the total number and size of flowering corms will increase.
Factors Affecting Bulb Size
– Bulb variety – some have larger natural corm sizes
– Growing conditions – optimal soil, sun, and moisture produce the largest bulbs
– Bulb age – corms may plateau in size after reaching maturity
– Storage conditions – improper winter storage can cause bulbs to shrink
– Disease – viral infections can stunt growth and reduce bulb size
Maximizing Bulb Size
To get the largest gladiolus bulbs from year to year:
– Provide excellent care and growing conditions in-season.
– Allow plants to fully mature and replenish the bulbs each year.
– Dig, cure, and store bulbs properly every season.
– Propagate new cormels to flowering maturity.
– Remove diseased plants and corms promptly.
With good care, gladiolus can maintain optimal bulb sizes and reach their full potential when saved from year to year.
Troubleshooting Issues with Saving Gladiolus Bulbs
Sometimes problems arise when trying to get gladiolus to rebloom from saved bulbs. Here are some common issues and solutions:
Bulbs Fail to Grow or Emergence is Weak
This may be caused by:
– Inadequate chill time over winter – store bulbs for 12+ weeks
– Damage during digging or storage – handle bulbs gently
– Rotting from excess moisture – store bulbs in dry environment
– Lack of nutrients in soil – fertilize at planting time
– Planting too shallow – plant bulbs 4-6 inches deep
No Flowers or Sparse, Small Blooms
Possible reasons include:
– Insufficient sun exposure – plant in full sun
– Overcrowding – space bulbs 6 inches apart
– Harvesting blooms too early – allow some flowers to mature
– Viruses present – remove and destroy affected plants
– Declining bulb vigor – replant only healthy bulbs each year
Foliage Dies Back Early
Causes can include:
– Water stress from drought or saturated soils
– Damaged or diseased bulbs
– Insufficient nutrients – fertilize per recommendations
– Overheating – provide afternoon shade in hot climates
– Pests like thrips – apply appropriate control measures
Leaf Spots or Distorted Growth
This may be due to:
– Fungal or bacterial diseases – improve air circulation
– Viruses – control spread by removing affected plants
– High soluble salts in soil – avoid overfertilizing
– Herbicide drift – avoid applying weed killers nearby
Bulbs Fail to Store Well Over Winter
Check for:
– Excess moisture during curing or storage – store in dry paper, not plastic
– Freezing temperatures – store bulbs around 40-45°F
– rodents, mold, or disease – protect bulbs properly in storage
– Physical damage from rough handling
– Insufficient curing period before storage
Conclusion
With proper care both in-season and during winter dormancy, gardeners can successfully save gladiolus bulbs and enjoy repeat blooms year after year. Take time each fall to carefully dig, cure, and sort bulbs for storage. Then replant the healthiest corms and cormels in spring. Maintain optimal growing conditions, and your gladiolus will continue providing colorful summer flowers that get bigger and more plentiful over time. Pay close attention to signs of disease and troubleshoot any issues that arise to keep bulbs flowering at their best.
