Although caladium bulbs can be picky about their environment (especially regarding temperature), they’re difficult to mess up. If you forgot to plant your caladium bulbs at the start of spring, you might be wondering if it’s too late to plant them.
It is never too late to plant caladium bulbs. These bulbs prefer soil temperatures above 70 °F (21.2 °C). Therefore, as long as soil temperatures are ideal, it is okay to plant caladium bulbs late. It is better to plant the bulbs too late rather than too early, as early planting can stunt growth.
The rest of this article will discuss when you should plant caladium bulbs depending on your location and which months are best for planting caladium bulbs. I’ll also go over how to prepare caladium bulbs for planting and what happens if you plant them too early. Read on!
How to Know When to Plant Caladium Bulbs
Knowing when to plant caladium bulbs is essential for the best growth. However, where you live significantly impacts when you should plant the bulbs, as the temperature is a crucial factor in plant growth.
Caladium plants must have warm to hot temperatures to grow. Therefore, these plants simply won’t grow in certain areas, especially if temperatures don’t get warm enough.
It’s usually ideal to plant caladium bulbs at the beginning of the spring season. However, it’s better to be a little more thorough before planting the bulbs in the ground, as the beginning of the spring season doesn’t always mean the weather is warm enough for the bulbs to sprout.
If you want to be completely confident in your timing when planting caladium bulbs, I suggest getting a soil thermometer. With caladiums, it’s essential that the soil temperature is 70 °F (21.1 °C) or above. This is the ideal growing temperature for caladium bulbs and will most likely produce the best results.
Knowing your hardiness level zone is the best way to determine when you should plant caladium bulbs. There are 13 hardiness level zones — each of which is determined by the USDA scale.
I’ll go over this scale in more detail in the next section.
Plant Hardiness Levels and What They Mean
Hardiness zones are categorized by the minimum winter temperature reached in each area. Therefore, it gives gardeners an idea of which plants are more likely to thrive in their specific location.
The zones are as follows:
- Zone 1: -60 to -50 °F (-51.1 to -45.5 °C)
- Zone 2: -50 to -40 °F (-45.5 to -40 °C)
- Zone 3: -40 to -30 °F (-40 to -34.4 °C)
- Zone 4: -30 to -20 °F (-34.4 to -28.8 °C)
- Zone 5: -20 to -10 °F (-28.8 to -23.3 °C)
- Zone 6: -10 to 0 °F (-23.3 to -17.7 °C)
- Zone 7: 0 to 10 °F (-17.7 to -12.2 °C)
- Zone 8: 10 to 20 °F (-12.2 to -6.6 °C)
- Zone 9: 20 to 30 °F (-6.6 to -1.1 °C)
- Zone 10: 30 to 40 °F (-1.1 to 4.4 °C)
- Zone 11: 40 to 50 °F (4.4 to 10 °C)
- Zone 12: 50 to 60 °F (10 to 15.5 °C)
- Zone 13: 60 to 70 °F (15.5 to 21.1 °C)
If you’re more of a visual learner, check out the map below:
Caladium plants are hardy to zones 9-11. However, this doesn’t mean you can only plant caladiums if you live in these zones, as they can survive in lower temperatures. Just be aware that you’ll have to make an extra effort to ensure that your bulbs thrive if you live in colder regions.
It’s best to understand your hardiness zone before planting your caladium bulbs in the spring, as it might be better to wait a little longer for warmer temperatures.
March Is the Best Month to Plant Caladiums
You should plant caladium bulbs in the month of March, especially for the hardiness zones 9-11. Around mid-March is when the soil temperatures in this area are warm enough for bulbs to thrive.
Although caladium bulbs are hardy to zone levels 9-11, they can still be planted in lower zone levels, as mentioned above.
Here’s a guide on when to plant caladium bulbs in zone levels 3-8:
- Zone 3: Mid-June
- Zone 4: Mid-June
- Zone 5: Mid-June
- Zone 6: The beginning of June
- Zone 7: The beginning of May
- Zone 8: Mid-April
However, it’s important to remember that this is just a guide and shouldn’t always be used. The general rule is to plant caladium bulbs when the soil temperature is warm enough for the bulbs to survive and thrive, which may or may not be during the month listed above.
It may help to check your local weather forecast or ask other experienced caladium bulb growers for their take on the matter.
Risks of Planting the Bulbs Too Early
While planting caladium bulbs too late isn’t a bad thing, planting them too early can be. Of course, this depends on the area you live in. So what happens if you plant your caladium bulbs too early?
Planting your caladium bulbs too early can result in stunted growth or bulb rot. Caladium bulbs prefer soil temperatures of 70 °F (21.2 °C) or higher to grow properly. Therefore, when you plant caladium bulbs too early, it leaves the bulbs in soil with too low temperatures.
Too low temperatures won’t allow the bulb to grow at all or will cause it to rot because of excess water. Caladium bulbs prefer warm, moist soil that drains well.
If you’re worried about accidentally planting caladium bulbs too early and don’t want to mess with a soil thermometer, you can still do some things to prepare the bulbs. I’ll go over this in the following sections.
How to Prepare Caladiums for Planting
Preparing your caladium bulbs for planting can consist of numerous things. For example, if you’d like to start your caladium plants but are not in an area that allows for outside planting, you can start them indoors. You can also soak the bulbs to get them out of dormancy.
Additionally, you can scar the bulbs beforehand for more growth and even save them for the next season (depending on where you live).
Let’s go over these preparations in more detail below.
Soak the Bulbs in Warm Water
Soaking caladium bulbs prior to planting is an excellent idea, especially if you live in a lower hardiness zone. Soaking the bulbs in warm water will “wake them up” from dormancy, giving them a kickstart to planting.
If you do want to soak the bulbs, it’s ideal to soak them for at least an hour. You can soak them overnight, but make sure they stay in warm water.
Cut or Scar the Bulbs
Cutting or “scarring” caladium bulbs before planting them will encourage more growth from the bulb. Caladium bulbs consist of one large, central bud surrounded by several small buds.
Taking a knife and scarring the buds or completely cutting out the central bud will force the bulb to sprout from the surrounding small ones, leading to fuller growth.
Store Them for Later Use
One of the unique aspects of caladium bulbs is you can dig them up and store them for the next season.
However, your hardiness zone plays a significant role in whether or not you should store the bulbs. For instance, in hardiness zone levels 9-11, you can leave the bulbs in the ground until the following season. Sometimes, treating the bulbs as annuals and not storing them is ideal, as they may not survive storage anyway.
However, in lower hardiness zone levels, it’s best to dig them up and store them. Leaving the bulbs in the soil in lower hardiness zone areas will cause the bulbs to disintegrate.
Plant Them Indoors
If you live in a lower hardiness zone or want to start the plant early, you can start the plant indoors. This not only gives your caladium a bit of a head start to the season, but it works out better in areas where the soil doesn’t reach ideal temperatures until later in the season.
It’s never too late to plant caladium bulbs, as planting them too late is better than planting them too early. Since caladium bulbs prefer soil temperatures of 70 °F (21.2 °C) or higher, they do better when planted later in the season. Moreover, planting the bulbs too early can lead to stunted plant growth or even bulb rot.
Caladium plants are hardy to levels 9-11. So, while planting at the start of spring is usually recommended, it’s best to know your area’s hardiness zone before planting any bulbs. Alternatively, use a soil thermometer and monitor the soil temperature.