Caladium Bulb Storage

Download PDF

Bulb Storage

Caladiums are tropical plants, and bulbs must be stored at temperatures above 60°F (16°C) with a relative humidity in the neighborhood of 75%. Also, there needs to be good air exchange to prevent build-up of gases. Caladiums are particularly sensitive to the presence of ethylene gas. When storing caladiums, unpack them immediately upon arrival and store them in open trays with proper air circulation. Exposing bulbs to cold temperatures will cause them to sprout slowly and erratically and cold may stunt the crop.

Stunted Growth

Make sure that bulbs are not stored at temperatures below 60°F (16°C), or above 90° (32°C). Injury due to temperature exposure manifests itself in stunted (sometimes very slow) erratic growth even though the bulb does not show any injury at all.

Moldy Bulbs

Occasionally we get calls regarding the receipt of moldy tubers. Though at first this appears to be a problem, in reality in most cases it is not a problem at all. Unlike many tubers, caladium tubers never go completely dormant and in fact maintain a rather high respiration rate. As you know respiration involves taking in oxygen (O2) and giving off carbon dioxide (CO2) and water (H2O). This results in a high relative humidity especially in a closed in environment, such as a shipping box. Caladium tubers also exfoliate, constantly shedding their outer epidermal layers. Combining dead epidermis with high humidity leads to saprophytic (non-pathogenic) mold growth on the surface of the tuber. The most common, widely occurring surface molds are the common bread molds (Aspergillus and/or Penicillium). Neither of these are plant pathogens.To mitigate this Classic Caladiums waits until the last minute to close up shipping boxes and ship by the fastest means practical. Nevertheless, it is important to open the boxes as soon as you get them to get air to the tubers thus lowering humidity. As indicated above, caladium tubers, even dormant ones, have high respiration rates. Tubers experiencing temperature changes during shipping and at the customers greenhouse can actually get condensate on them further exacerbating the possibility of mold.We hope you don’t experience mold on the caladium tubers you receive, however if you do don’t worry, just open the boxes immediately allowing air to reach the tubers and plant them as soon as possible.

Tuber Shrinkage and Breakage

Click here for more info.

Caladium Tuber Storage Life

During storage, the tops of the caladium tubers cannibalize the base to survive. The longer tubers are stored and the warmer they are stored the more cannibalization (due to increased respiration rates) takes place, increasing the amount of dead basal tissue, until they finally exhaust all their stored reserves and die. The tops only remove from the basal tissue what is needed (water, nutrients, starch/sugar, etc.) to survive, but leave behind dead organic tissue which when hydrated serves as a food source for saprophytic (non-pathogenic) organisms (fungi/bread mold and bacteria). As long as the top portion of the tuber is firm and when scratched there is yellow firm tuber tissue, the tuber will perform. Imagine gluing a slice of bread to the base of the bulb, what would you expect to happen to the slice of bread? It would hydrate, mold and rot.Tuber storage life is dependent on variety, growing status of the variety when harvested, processing damage and storage conditions.

  1. Variety: Certain caladium varieties store better than others. Classic Caladiums is doing ongoing studies on the storage capabilities of each variety.
  2. Growing Status when Harvested: To meet market demands harvesting begins before most varieties are naturally dormant. Leaves are mowed off and tubers are harvested which exhibit roots. These “rooty” tubers, though performing normally when planted, tend to store less favorably and shrink more.
  3. Processing Damage:a. Caladium tubers are mechanically harvested with a digger that is similar to a potato digger. Tubers are harvested into live bottom bulb trailers and then taken and unloaded at our washer. Though we do all we can to reduce mechanical injury some injury occurs. Certain varieties are more prone to injury than others as are larger tubers when compared to smaller tubers. Damaged tubers store less well than non-damaged tubers.b. After washing tubers are cured for 2 weeks, at 85°F with good air flow and circulation, after which they are graded and counted. After counting they are returned to the curing room for 24 hours to allow any new grading related wounds to begin healing, after which the are placed in our warehouse and added to our salable inventory.
  4. Storage Conditions: Typically, tubers are stored in the processing warehouse from December through April. Warehouse temperatures during this period run from 65-85°F. Most operations continue to store and ship from the warehouse through July. During the period May-July temperatures often reach 100°F on a daily basis. These high temperatures increase tuber respiration and reduce the life of the tubers. Classic Caladiums is experimenting with long term (9-12 months) tuber storage at 65°F and >50% relative humidity. It appears that many varieties store well under these conditions.

Caladium Bulb Sizes

What are the bulb sizes?

Click here to see caladium bulb sizes.

De-Eye Caladiums

Classic now offers de-eying (and bulb painting) services to our commercial clients for a small fee. Contact your broker or Classic for more information.

Bulbs sold by us and our co-branding partner, Proven Winners are de-eyed unless specifically ordered otherwise.

Download PDF

How to DE-EYE?

To de-eye, cut out the terminal/dominant buds or sprout(s) (eyes) using a small knife or tool (pictured above). Staying within the diameter of the eye, remove the entire eye by cutting about 1/8” – 1/4” deep into the bulb. Remember, it is critical to stay within the diameter of the eye to eliminate damage to the small eyes (axillary or lateral buds) that surround the perimeter of the main eye. This is demonstrated first with a green bulb where the axillary buds are clearly visible.

  • Bulb with dominant buds
  • Remove the entire eye by cutting 1/8″ to 1/4″ deep – stay with in the eye diameter
  • Bulb after de-eye

Experiments using a nail to puncture and destroy the terminal bud have shown good results. Remember in order to be effective, the de-eyeing method must remove or destroy the terminal buds. Please note however while proper de-eyeing increases the uniformity of your crop, increasing the severity of the de-eyeing treatment, by excessive removal of tuber tissue surrounding the terminal eyes, leads to a less uniform crop.  Cluster bulbs, those with four or five terminal eyes, generally do not benefit from de-eying. Contrary to some beliefs, it is not harmful to de-eye white cultivars as long as it is done properly, e.g. stay within the diameter of the terminal eye. The caladium bulb, being a storage organ, is full of carbohydrates. A wet carbohydrate source invites disease problems, soit is best to let a de-eyed bulb dry and heal 10-12 hours before potting. Use a fungicide or Talc dust to aid in this process may be helpful. Good air circulation is very important to this drying (healing) process.  The apical (terminal) shoot (bud) is more mature than the axillary buds surrounding it. After de-eyeing, shoots/leaves from axillary buds may have a slightly different (more juvenile) look and color.  Although de-eyeing will delay the forcing time briefly (up to two weeks), it will result in a fuller more compact plant. Therefore, we recommend that all bulbs used for pot plants, except as noted in the variety descriptions, be de-eyed. We do not recommend the use of GA on caladiums to stimulate germination as it causes excessive stretching (petiole elongation).

Fancy or Strap

There are differences in appearance and performance between strap caladiums and fancy caladiums.

How can you tell if it's Fancy Leafed?

Generally, fancy leaf caladiums have larger & heart shaped leaves and taller growth heights.

The petiole is centered on the underside of a fancy leafed caladium.

Click here for more details.

How can you tell if it's Strap Leafed?

Physically, strap caladiums tend to be narrower lance-leaf caladiums, usually short in height and may have better sun tolerances.

Strap leafed caladiums – the petiole meets the underside of the leaf at the apex.

Click here for more details.

Moldy Caladium Tubers

Download PDF

Moldy Caladium tubers in your shipment.

Occasionally we get calls regarding the receipt of moldy tubers. Though at first this appears to be a problem, in reality in most cases it is not a problem at all. Unlike many tubers, caladium tubers never go completely dormant and in fact maintain a rather high respiration rate. As you know respiration involves taking in oxygen (O2) and giving off carbon dioxide (CO2) and water (H2O). This results in a high relative humidity especially in a closed in environment, such as a shipping box. Caladium tubers also exfoliate, constantly shedding their outer epidermal layers. Combining dead epidermis with high humidity leads to saprophytic (non-pathogenic) mold growth on the surface of the tuber. The most common, widely occurring surface molds are the common bread molds (Aspergillus and/or Penicillium). Neither of these are plant pathogens.To mitigate this Classic Caladiums waits until the last minute to close up shipping boxes and ship by the fastest means practical. Nevertheless, it is important to open the boxes as soon as you get them to get air to the tubers thus lowering humidity. As indicated above, caladium tubers, even dormant ones, have high respiration rates. Tubers experiencing temperature changes during shipping and at the customers greenhouse can actually get condensate on them further exacerbating the possibility of mold.We hope you don’t experience mold on the caladium tubers you receive, however if you do don’t worry, just open the boxes immediately allowing air to reach the tubers and plant them as soon as possible.

Click here for more details.

Sun Burned Caladium Leaves

How should I manage sun exposure for my Caladiums?

Even with sun tolerant varieties, the first emerging leaves can burn in full sun conditions especially if the humidity is low and the temperatures are high.  Later emerging leaves should perform fine given sufficient water.Caladiums are native to tropical rain forests and the equatorial regions of Latin America and can be found from southern Mexico to northern Peru.  Some species are reported from the Caribbean Island regions of Puerto Rico and the Lesser Antilles.  Most species come from the Amazon basin in Brazil where they typically grow along river banks under a canopy of forest trees.  Thus, in the wild, caladiums are typically found in shaded locations.  Through breeding and selection many newer varieties are sun tolerant and can be grown in the full sun (see variety descriptions). 

White and pink cultivars that have been grown during cloudy, early spring days and are suddenly exposed to high light intensity and low humidity (such as when a late cool front passes) might show brown blotches on the leaves.  Additional shade will stop this problem.  Red varieties are not as prone to sun burning.

Click here for more details.

Frequently Asked Questions

Caladium Bulb Storage

Download PDF

Bulb Storage

Caladiums are tropical plants, and bulbs must be stored at temperatures above 60°F (16°C) with a relative humidity in the neighborhood of 75%. Also, there needs to be good air exchange to prevent build-up of gases. Caladiums are particularly sensitive to the presence of ethylene gas. When storing caladiums, unpack them immediately upon arrival and store them in open trays with proper air circulation. Exposing bulbs to cold temperatures will cause them to sprout slowly and erratically and cold may stunt the crop.

Stunted Growth

Make sure that bulbs are not stored at temperatures below 60°F (16°C), or above 90° (32°C). Injury due to temperature exposure manifests itself in stunted (sometimes very slow) erratic growth even though the bulb does not show any injury at all.

Moldy Bulbs

Occasionally we get calls regarding the receipt of moldy tubers. Though at first this appears to be a problem, in reality in most cases it is not a problem at all. Unlike many tubers, caladium tubers never go completely dormant and in fact maintain a rather high respiration rate. As you know respiration involves taking in oxygen (O2) and giving off carbon dioxide (CO2) and water (H2O). This results in a high relative humidity especially in a closed in environment, such as a shipping box. Caladium tubers also exfoliate, constantly shedding their outer epidermal layers. Combining dead epidermis with high humidity leads to saprophytic (non-pathogenic) mold growth on the surface of the tuber. The most common, widely occurring surface molds are the common bread molds (Aspergillus and/or Penicillium). Neither of these are plant pathogens.

To mitigate this Classic Caladiums waits until the last minute to close up shipping boxes and ship by the fastest means practical. Nevertheless, it is important to open the boxes as soon as you get them to get air to the tubers thus lowering humidity. As indicated above, caladium tubers, even dormant ones, have high respiration rates. Tubers experiencing temperature changes during shipping and at the customers greenhouse can actually get condensate on them further exacerbating the possibility of mold.

We hope you don’t experience mold on the caladium tubers you receive, however if you do don’t worry, just open the boxes immediately allowing air to reach the tubers and plant them as soon as possible.

Tuber Shrinkage and Breakage

Click here for more info.

Caladium Tuber Storage Life

During storage, the tops of the caladium tubers cannibalize the base to survive. The longer tubers are stored and the warmer they are stored the more cannibalization (due to increased respiration rates) takes place, increasing the amount of dead basal tissue, until they finally exhaust all their stored reserves and die. The tops only remove from the basal tissue what is needed (water, nutrients, starch/sugar, etc.) to survive, but leave behind dead organic tissue which when hydrated serves as a food source for saprophytic (non-pathogenic) organisms (fungi/bread mold and bacteria). As long as the top portion of the tuber is firm and when scratched there is yellow firm tuber tissue, the tuber will perform. Imagine gluing a slice of bread to the base of the bulb, what would you expect to happen to the slice of bread? It would hydrate, mold and rot.

Tuber storage life is dependent on variety, growing status of the variety when harvested, processing damage and storage conditions.

  1. Variety: Certain caladium varieties store better than others. Classic Caladiums is doing ongoing studies on the storage capabilities of each variety.
  2. Growing Status when Harvested: To meet market demands harvesting begins before most varieties are naturally dormant. Leaves are mowed off and tubers are harvested which exhibit roots. These “rooty” tubers, though performing normally when planted, tend to store less favorably and shrink more.
  3. Processing Damage:
    a. Caladium tubers are mechanically harvested with a digger that is similar to a potato digger. Tubers are harvested into live bottom bulb trailers and then taken and unloaded at our washer. Though we do all we can to reduce mechanical injury some injury occurs. Certain varieties are more prone to injury than others as are larger tubers when compared to smaller tubers. Damaged tubers store less well than non-damaged tubers.
    b. After washing tubers are cured for 2 weeks, at 85°F with good air flow and circulation, after which they are graded and counted. After counting they are returned to the curing room for 24 hours to allow any new grading related wounds to begin healing, after which the are placed in our warehouse and added to our salable inventory.
  4. Storage Conditions: Typically, tubers are stored in the processing warehouse from December through April. Warehouse temperatures during this period run from 65-85°F. Most operations continue to store and ship from the warehouse through July. During the period May-July temperatures often reach 100°F on a daily basis. These high temperatures increase tuber respiration and reduce the life of the tubers. Classic Caladiums is experimenting with long term (9-12 months) tuber storage at 65°F and >50% relative humidity. It appears that many varieties store well under these conditions.

Caladium Bulb Sizes

What are the bulb sizes?

Click here to see caladium bulb sizes.

De-Eye Caladiums

Classic now offers de-eying (and bulb painting) services to our commercial clients for a small fee. Contact your broker or Classic for more information.

Bulbs sold by us and our co-branding partner, Proven Winners are de-eyed unless specifically ordered otherwise.

Download PDF

How to DE-EYE?

To de-eye, cut out the terminal/dominant buds or sprout(s) (eyes) using a small knife or tool (pictured above). Staying within the diameter of the eye, remove the entire eye by cutting about 1/8” – 1/4” deep into the bulb. Remember, it is critical to stay within the diameter of the eye to eliminate damage to the small eyes (axillary or lateral buds) that surround the perimeter of the main eye. This is demonstrated first with a green bulb where the axillary buds are clearly visible.

  • Bulb with dominant buds
  • Remove the entire eye by cutting 1/8″ to 1/4″ deep – stay with in the eye diameter
  • Bulb after de-eye

Experiments using a nail to puncture and destroy the terminal bud have shown good results. Remember in order to be effective, the de-eyeing method must remove or destroy the terminal buds. Please note however while proper de-eyeing increases the uniformity of your crop, increasing the severity of the de-eyeing treatment, by excessive removal of tuber tissue surrounding the terminal eyes, leads to a less uniform crop.

  Cluster bulbs, those with four or five terminal eyes, generally do not benefit from de-eying. Contrary to some beliefs, it is not harmful to de-eye white cultivars as long as it is done properly, e.g. stay within the diameter of the terminal eye. The caladium bulb, being a storage organ, is full of carbohydrates. A wet carbohydrate source invites disease problems, soit is best to let a de-eyed bulb dry and heal 10-12 hours before potting. Use a fungicide or Talc dust to aid in this process may be helpful. Good air circulation is very important to this drying (healing) process.

  The apical (terminal) shoot (bud) is more mature than the axillary buds surrounding it. After de-eyeing, shoots/leaves from axillary buds may have a slightly different (more juvenile) look and color.
  Although de-eyeing will delay the forcing time briefly (up to two weeks), it will result in a fuller more compact plant. Therefore, we recommend that all bulbs used for pot plants, except as noted in the variety descriptions, be de-eyed. We do not recommend the use of GA on caladiums to stimulate germination as it causes excessive stretching (petiole elongation).

Fancy or Strap

There are differences in appearance and performance between strap caladiums and fancy caladiums.

How can you tell if it's Fancy Leafed?

Generally, fancy leaf caladiums have larger & heart shaped leaves and taller growth heights.

The petiole is centered on the underside of a fancy leafed caladium.

Click here for more details.

How can you tell if it's Strap Leafed?

Physically, strap caladiums tend to be narrower lance-leaf caladiums, usually short in height and may have better sun tolerances.

Strap leafed caladiums – the petiole meets the underside of the leaf at the apex.

Click here for more details.

Moldy Caladium Tubers

Download PDF

Moldy Caladium tubers in your shipment.

Occasionally we get calls regarding the receipt of moldy tubers. Though at first this appears to be a problem, in reality in most cases it is not a problem at all. Unlike many tubers, caladium tubers never go completely dormant and in fact maintain a rather high respiration rate. As you know respiration involves taking in oxygen (O2) and giving off carbon dioxide (CO2) and water (H2O). This results in a high relative humidity especially in a closed in environment, such as a shipping box. Caladium tubers also exfoliate, constantly shedding their outer epidermal layers. Combining dead epidermis with high humidity leads to saprophytic (non-pathogenic) mold growth on the surface of the tuber. The most common, widely occurring surface molds are the common bread molds (Aspergillus and/or Penicillium). Neither of these are plant pathogens.

To mitigate this Classic Caladiums waits until the last minute to close up shipping boxes and ship by the fastest means practical. Nevertheless, it is important to open the boxes as soon as you get them to get air to the tubers thus lowering humidity. As indicated above, caladium tubers, even dormant ones, have high respiration rates. Tubers experiencing temperature changes during shipping and at the customers greenhouse can actually get condensate on them further exacerbating the possibility of mold.

We hope you don’t experience mold on the caladium tubers you receive, however if you do don’t worry, just open the boxes immediately allowing air to reach the tubers and plant them as soon as possible.

Click here for more details.

Sun Burned Caladium Leaves

How should I manage sun exposure for my Caladiums?

Even with sun tolerant varieties, the first emerging leaves can burn in full sun conditions especially if the humidity is low and the temperatures are high.  Later emerging leaves should perform fine given sufficient water.

Caladiums are native to tropical rain forests and the equatorial regions of Latin America and can be found from southern Mexico to northern Peru.  Some species are reported from the Caribbean Island regions of Puerto Rico and the Lesser Antilles.  Most species come from the Amazon basin in Brazil where they typically grow along river banks under a canopy of forest trees.  Thus, in the wild, caladiums are typically found in shaded locations.  Through breeding and selection many newer varieties are sun tolerant and can be grown in the full sun (see variety descriptions). 

White and pink cultivars that have been grown during cloudy, early spring days and are suddenly exposed to high light intensity and low humidity (such as when a late cool front passes) might show brown blotches on the leaves.  Additional shade will stop this problem.  Red varieties are not as prone to sun burning.

Click here for more details.