Calla lilies are prized for their colorful flowers, ranging from white and yellow to red and purple. These beautiful perennials can make your garden vibrant with lush foliage and bright flowers. That’s why it can be alarming when you can’t find the characteristic blooms in spring or summer.
Calla lilies can grow healthy leaves without flowers if they have been overfertilized with a high-nitrogen fertilizer. The lack of phosphorus can also significantly reduce the chance of calla lily flowers blooming. Another reason could be insufficient sunlight and water.
Many factors can contribute to the absence of flowers in your calla lilies. This article will discuss these things in detail and recommend how to overcome them.
Calla lilies are perennials that come back with new blooms year after year. Although the leaves are a beauty by themselves, the flowers make the plant even more appealing. Unfortunately, several issues can prevent your calla lily from developing flowers. Here are some of them:
Every gardener knows that plants need three essential macronutrients for growth: nitrogen, phosphorus, and potassium. However, each plant needs varying levels of these nutrients, depending on some factors, such as:
- The plant’s age. Young plants need a balanced fertilizer. Nitrogen helps plants develop strong leaves. And as an important component of proteins, it helps with the overall structure of the plants. Phosphorus helps strengthen the roots and aids in photosynthesis. Meanwhile, potassium helps boost the plant’s defense against diseases.
- The season. During the growing season, plants need sufficient fertilizer to encourage growth. However, many flowering plants may benefit from cutting back on nitrogen fertilizers before dormancy.
- The plant’s growth pattern. Foliage plants prefer high-nitrogen fertilizers. On the other hand, fruiting and flowering plants need more phosphorus.
- The fertility of the soil. In addition to the three macronutrients, plants also need trace amounts of micronutrients, such as iron, calcium, and magnesium. If the soil lacks these nutrients, it can have detrimental effects on your plants.
For established calla lilies that had a few years of flourishing blooms, the nutrients you must pay attention to are nitrogen and phosphorus. They are vital to determining the appearance of flowers year after year.
All plants need a good dose of nitrogen, which is responsible for their healthy foliage and roots. It is also an essential component of chlorophyll, making it a crucial part of all plants’ basic food-making process called photosynthesis.
However, excessive amounts of nitrogen can be detrimental to fruiting or flowering plants. Supplementing them with nitrogen will encourage them to allot their energy to leaf growth, inhibiting the development of fruits or buds.
Therefore, applying too much nitrogen is one of the reasons why your calla lilies have plenty of leaves but lack flowers.
Plants also need phosphorus for root health and fruit or flower development. Foliage plants typically don’t need as much phosphorus as flowering plants like calla lilies.
Moreover, fertile soil usually has enough phosphorus because it is not as easily lost in the nutrient cycle as nitrogen. That’s why many gardeners don’t often use phosphorus-heavy fertilizers in their gardens.
However, if your calla lilies failed to produce flowers, it could be due to two phosphorus-related problems:
- There isn’t enough phosphorus in the soil. This may be one of the most obvious reasons, as it can be easy to overlook this issue if you’ve had a few years of successful calla lily blooms. However, the phosphorus in the soil must have been used up, leading to the absence of this year’s blooms.
- The roots are unable to absorb the phosphorus. The soil often has enough phosphorus, but the roots cannot absorb them due to poor health. Calla lilies love moisture but like most plants, frequently sitting in too much water can damage their roots, preventing them from absorbing essential nutrients from the soil.
Therefore, the lack of phosphorus in the soil is not always the problem. It might be the plant roots’ inability to absorb nutrients. If the latter is the case, you’d see other symptoms, such as:
- Small leaves
- Stunted growth
Calla lilies are best grown outdoors in a sunny location, especially in USDA zones 8 and above, such as Florida and California. Under the right conditions, these plants can grow vigorously and produce large blooms.
However, the plant will become leggy when grown indoors with insufficient sunlight. The leaves may grow leaning towards the light source. The plant will also fail to produce flowers because it cannot generate enough food for the buds to develop.
Water is an essential requirement for all plants to thrive – although in varying amounts. Calla lilies need enough water for optimum health and to produce flowers.
Too much water is bad as it can damage the roots and significantly reduce their ability to absorb soil nutrients. It can make the soil conducive to fungal growth and make the plant susceptible to infections like root rot.
On the other hand, insufficient moisture will make nutrients inaccessible to the roots. Various nutrients in the soil need enough water for the following reasons:
- Chemical reactions. Many nutrients in the ground are not readily useful for plants. They must be broken down through hydrolysis before the roots can absorb them. Without water, these chemical reactions will not occur.
- Movement. Enough water in the soil is necessary to move the nutrients closer to the roots. Calla lilies need frequent watering during the growing season, early in spring. However, too much water can leach nutrients beyond the reach of the roots. That’s why it’s also necessary to apply fertilizers.
After the blooming period, calla lily leaves gradually dry up as the temperatures drop. Your plant produces new buds underground for next year’s blooms and generates enough food for them before the leaves completely die back.
Winter is a crucial period for calla lilies that can help determine whether or not the plants can bloom in spring. The lack of a cold period and dormancy will prevent the plant from producing flowers.
Flowering perennials need a cold period or shorter daylight or both as stimuli to tell them to go into dormancy. As herbaceous perennials, calla lilies depend on these signals to save their energy for new growth in the following spring.
When the temperatures become favorable again, the plant will break out of dormancy and resume activity. If the calla lily hasn’t stored enough food for the buds before dormancy, it might reduce the number of blooms.
On the other hand, if the plant continues to be active during winter, especially in warmer regions, its leaves will grow as usual, but the plant will not produce flowers at all.
Harsh winters can also prevent your calla lilies from growing back the following year. The rhizomes can die when frozen underground because calla lilies are not tolerant to freezing temperatures.
Some people treat their calla lilies as annuals, especially in cold regions. If you don’t see flowers after treating your plant as a perennial and witnessing a few years of successful blooms, you can follow a series of steps to ensure the flowers come back next year.
In spring, as the temperatures warm enough for the calla lilies to sprout, you can apply a balanced liquid fertilizer. Note that calla lilies need plenty of water during the growing season, so you need to use fast-acting fertilizers to prevent the nutrients from leaching deep into the ground.
Apply the fertilizers as frequently as recommended on the product label. You can switch to a high-phosphorus liquid fertilizer when you see the buds. When the flowers are in full bloom, you can go back to your balanced fertilizer.
After the blooming period – typically in the middle or late summer – cut back on feeding your calla lilies nitrogen fertilizers. It will help facilitate your plants’ transition to dormancy.
If you live in USDA zone 8-10, you can grow your calla lilies outdoors and keep them there all year round. Ensure that the location receives sufficient shade from the intense afternoon sun.
However, in colder regions, you may want to grow them indoors. Just be sure to provide them with bright light for at least eight hours a day. You can do this by placing your potted calla lilies next to an east-facing or south-facing glass door or window.
Calla lilies like well-draining humus-rich soil. When grown in such a medium, you can water them thoroughly every 3-4 days during the growing season, depending on how quickly your soil drains the water.
The buds need enough water to bloom, so you must keep your plants hydrated. However, it can be counterproductive to overwater your calla lilies, as it can damage the roots. To avoid this, check with your fingers to confirm if the upper 2 inches (5 cm) of the soil is dry. If so, then it’s time to water your plants again.
When growing calla lilies in colder regions – USDA zone 7 and below – it can be challenging to perennialize them. However, you can give it a shot by digging out the rhizomes in the fall once the leaves have died.
Here’s how to store your calla lily rhizomes in winter:
- Carefully dig out the rhizomes from the ground and avoid damaging them with your gardening tools.
- Remove the soil using gentle running water and allow the rhizomes to dry for about a week.
- Place individual bulbs/rhizomes in separate paper bags and store them in a dark room with a steady temperature between 50 and 60°F (10 and 15.6°C).
- Inspect the rhizomes once a month and spray them with little water to prevent them from drying out.
- Plant them in the ground or pots with soil rich in organic matter when the temperatures rise to 70°F (21.1°C). Ensure that the top of the rhizome is at least 2 inches (5 cm) below the soil surface.
These steps can help ensure that your calla lily rhizomes are well-protected in winter and allow them to bloom again in spring.
Calla lilies may grow healthy-looking leaves but fail to produce flowers when it receives high amounts of nitrogen but not enough phosphorus. Other factors that could cause such an issue are poor watering practices, insufficient sunlight, and lack of dormancy period.
You can overcome this problem by providing your calla lilies with adequate fertilizer, water, and sunlight. Moreover, if mulching is not enough, you may need to dig out the rhizomes during harsh winters to protect them from the freezing cold that could damage the developing buds
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Hi! I’m Sophia, and I love plants – especially an expert in growing house plants. I stay in Chicago, United States of America, and through my blog and social media platforms, provide tips and tricks on how to grow healthy, vibrant plants indoors. Check out more here.