Top 10 Questions About Calla Lily Plants

Calla lilies add interest and tropical flair to both indoor and outdoor gardens, but these beautiful flowers are not without their share of troubles. Gardening Know How tries to provide the best information possible not only for growing healthy plants like this, but also to answer whatever gardening questions you may have along the way.

Here are the top questions about calla lilies.

1) How to care for potted calla lily plants? Potted calla lilies are often given as gifts. If you've received a calla lily and do not live in a warm enough climate to plant it outdoors, it will need a little extra care to grow well indoors.

Calla lily care, indoors or out, is pretty much the same - they need a lot of light. Place indoor calla lilies in a location where they will receive plenty of sunlight but are protected from drafts. Indoor callas also need a lot of water and regular feeding. Water thoroughly whenever the top layer of soil looks dry or the plant looks limp. Fertilizer indoor calla lilies once a month with a balanced general-purpose fertilizer. Indoor plants will also need a rest period to grow and bloom properly. To simulate dormancy, stop watering your potted calla after it blooms, allow it to die back, then place it in a cool (but not cold), dark location for two months. After its rest, return it to a location with bright light and water it regularly.

2) Why are calla lily blossoms turning green? Calla lily blooms that turn green after flowering for a while is a common and natural condition. As calla flowers mature, the plant's energy is focused on seed production. As the plant sets seeds, the flowers and other parts of the plant will die back from lack of energy and nutrients.

Simply deadhead spent blooms so energy is not wasted on seed production. After blooming, your calla lily will require a rest period. Outdoor plants will do this naturally, but indoor plants may require a mock dormancy period.

3) Why are calla lily leaves turning yellow? Yellowing leaves on any plant is usually a sign of nutrient deficiencies or improper watering habits. If your calla lily leaves are yellowing, first consider the timing. If the plant has just finished blooming, it could just be taking a natural rest period; simply cut it back and allow it to go dormant.

Also consider your fertilizing routine. Calla lilies should be fed once a month with a balanced general purpose fertilizer. They do not require feeding while dormant, but if you are not fertilizing them regularly the rest of the time, you should start. Callas also require full sun. Indoor plants can yellow from insufficient light. Indoor and outdoor calla lilies require regular watering, but these plants are pretty good at letting you know when they are thirsty by looking limp. Always water calla lilies deeply, as just a little spritz now and again won't do.

4) Why is my calla lily plant drooping? The most common reason for a drooping calla lily is lack of water. Calla lilies have high water needs. Always water outdoor calla lilies deeply and thoroughly when you water them. A nice long, slow trickle with a soaker hose allows the plant to soak up more of the water than a drenching blast.

Indoor calla lilies should be watered deeply whenever the top layer of soil looks dry. Again, a slow watering works best, allowing water to seep out from the pot's drainage holes. Calla lilies can also get droopy when they go into dormancy. This is just a natural and necessary process for the plant.

5) How to care for calla lily in winter? Calla lilies are not cold-hardy, and generally only thrive year round in U.S. zones 8 or above. If you live in zone 8 or above, the only winter care required for callas is to stop watering them so they can go dormant. You can protect them from low temperatures with a nice heap of mulch over the root zone. In zones 7 or lower, you will have to grow calla lilies as a container plant or as tropical bulbs, like canna or elephant ear. If container grown, move the plant indoors and stop watering. Give it a dormancy period in a cool, dark location for about two months in winter. Treated as other tropical bulbs, dig up the rhizomes in fall, cut off any foliage and let them dry out. Store the bulbs through winter in a dark, dry location where temperatures stay between 50-55 degrees F. (10-13 C.).

6) How to make a calla lily bloom? If an indoor calla lily no longer blooms or fails to at all, it could be lacking nutrients or it could simply need a rest period to store up new energy and regenerate.

You can simulate a dormancy period in winter by not watering your calla lily and storing it in a cool, dark location for about two months. Outdoor calla lilies will die back naturally and go dormant when they need to. If your calla lilies have properly rested but still refuse to bloom, they could be lacking phosphorus. Try a bloom-boosting fertilizer or bone meal to balance its nutrient needs. Then fertilize it regularly with a well-balanced fertilizer.

7) When and how to divide calla lilies? Calla lilies are rhizomatous plants, which makes them very easy to divide.

If calla lilies are not hardy in your zone but you grow them as annual bulbs, in fall when your calla lily begins to rest for winter, dig up the rhizomes and cut back any foliage still left on the plant. Let the rhizomes dry out and store them in a dark, cool, dry place throughout winter. In spring, when you take them out to plant them, simply cut apart any young rhizomes growing off of older ones and plant the individual pieces. If calla lilies are hardy in your area, simply dig the plant up in early spring, while it is still dormant. With a clean, sharp knife, cut apart new rhizome growth and plant them individually.

8) What causes calla lily blooms not to open? If calla lilies are not blooming properly, they could need a boost of phosphorous. You can give them a little extra phosphorus by adding bone meal or feeding them with a bloom boosting fertilizer. A bloom boosting fertilizer will have a higher middle number in its NPK ratio; for example, 5-15-5. It is especially important that fertilizer for blooms has very little nitrogen in it, as nitrogen promotes green, leafy growth rather than blossoms. To start your calla lily out with healthy blooms, feed it bone meal each spring.

9) What is growing inside my spent calla lily flower? As calla lily flowers mature and fade, they form seed pods. If you are seeing new growth in a spent calla lily flower, it is most likely this seed pod. You can simply deadhead these spent flowers, sending the plant's energy to its foliage and rhizomes to create new flowers.

If you'd like to try your hand at growing calla lilies from seed, you can leave the seed pods on the plant until they mature and dry out. Propagating calla lilies from seed is a very slow going process that requires a lot of patience; therefore, it is easiest and quickest to propagate them by divisions.

10) Why are the leaves on calla lily dripping liquid? When calla lilies are over-watered, they may ooze or transpire excessive liquid. This is called guttation. Calla lilies should only be watered as needed.

To check if a calla lily needs water, stick your fingertip in the soil. If it feels dry, then water it thoroughly; if it feels wet, do not water it until the soil dries out.

Calla lilies are also good at letting you know when they want water by going limp. Oozing on plants can also be a sign of pest or disease. If it seems that only one wounded looking area of your calla lily is oozing, I suggest snipping that infected part off, disposing of it and treating the whole plant with neem oil.

We all have questions now and then, whether long-time gardeners or those just starting out. So if you have a gardening question, get a gardening answer. We're always here to help.