Birds of Paradise Problems

(Question)

Hello, I don’t know what is going on but my birds of paradise has a host of problems and I don’t know what to do.

The room condition is bright room with no sunlight- is that okay ?
Climate zone 6.
Looking forward for your help.
Thank you

(Answer)

Thank you for contacting the Toronto Master Gardeners concerning your Bird of Paradise plant  (Strelitzia nicolai)

“Unfortunately, the top two photos are quite blury so I am unable to make out what exactly is on the petiole. We have a number of archived posts on our website with detailed information on the possible pests and diseases that could affect your Bird of paradise. Simply type Bird of Paradise into the Find it Here box located on the right side of the page.

The following information is from a number of these archived posts:

Bird of Paradise does not suffer from any serious pest or disease problems, but root rot, mealy bug, scale, bacterial wilt and leaf blight are quite common. Have you inspected your plant for any pests? Make sure to check the underside of the leaves.

Leaf spot, which can be caused by a bacteria or fungus, can also affect the leaves – and might be responsible for the black spots in your photo.  This type of fungal disease tends to occur when there is too much moisture present. The spots on the leaves will be 0.1-2 cm. big. Sometimes, the spots are regularly shaped like a circle, and other times the spots have a more irregular shape. Typically, the fungal spots are a lighter gray on the inside, while the outside of the spots are much darker or even black in color. The spots can also be brown or yellowish in color. It is difficult for me to see the spots on your photo.

Bird of Paradise does not suffer from any serious pest or disease problems, but root rot, mealy bug, scale, bacterial wilt and leaf blight are quite common. Have you inspected your plant for any pests? Make sure to check the underside of the leaves.

Leaf spot, which can be caused by a bacteria or fungus, can also affect the leaves – and might be responsible for the black spots in your photo.  This type of fungal disease tends to occur when there is too much moisture present. The spots on the leaves will be 0.1-2 cm. big. Sometimes, the spots are regularly shaped like a circle, and other times the spots have a more irregular shape. Typically, the fungal spots are a lighter gray on the inside, while the outside of the spots are much darker or even black in color. The spots can also be brown or yellowish in color. It is difficult for me to see the spots on your photo. Check the spots on your plant with the description provided.

The good news is that this disease typically does not cause any long-term damage to the plant. Proper cultural conditions and sanitization practices will help stem the spread of this disease. Remove infected leaves and any infected leaf bits that have fallen onto the soil and be sure not to get water on the leaves. Water early in the day so that the surfaces of the leaves have time to dry relatively quickly.

Another possibility for your symptoms is over watering along with improper light conditions. In proper lighting conditions ( full sun) the Bird of Paradise drinks plenty of water. If your plant is not receiving enough light, it is more susceptible to overwatering. Some indications that your plant could be overwatered are droopy leaves, excessive splitting, and browning edged leaves with a yellow line. How often do you water your plant? Birds of paradise tolerate dryness and mature plants may only need to be watered once a week – allow the top 5 cm (2 inches) of soil to dry before watering.  Make sure there is plenty of space around the plant so it gets good air circulation.  The plant should also be in a pot that has a drainage hole, so excess water can flow out – it does not like wet feet.

Bird of Paradise grows best in rich, well-draining soil. Using a typical potting mix for indoor houseplants available at any reputable garden center would be ideal for your plant.

Light is another consideration.  Bird of Paradise plants can tolerate a range of light levels.  If your plant is currently in medium to low light conditions, consider increasing the light including direct sunlight for up to 4-5 hours / day and monitor the effect.

You may be interested in general information regarding watering indoor plants from the Missouri Botanical Garden and light requirements for indoor plants from the House Plant Journal included in the links below.

https://www.houseplantjournal.com/bright-indirect-light-requirements-by-plant/

If the soil has been too wet or the plant has been over-watered, one concern might be a fungal disease called root rot – symptoms would include discolouration of leaves and death of branches, and with one type of root rot (armillaria) there would be clumps of mushrooms at the base of the plant.   Bacterial wilt can also attack birds of paradise – this is a bacterium carried in the soil that initially causes leaves to wilt and yellow and the base of the plant would turn brown or black at the soil line.  As you mention only the leaf, and not any other part of the plant being affected, I don’t believe that either of these are the culprit.

Leaf spot, which can be caused by a bacteria or fungus, can also affect the leaves – and might be responsible for the black spots in your photo.   Common causes are excessive moisture or poor air circulation.  Remove infected leaves and any infected leaf bits that have fallen onto the soil and be sure not to get water on the leaves.   Water early in the day so that the surfaces of the leaves have time to dry relatively quickly. Birds of paradise tolerate dryness and mature plants may only need to be watered around once a week – allow the top 5 cm (2 inches) of soil to dry before watering.   Make sure there is plenty of space around the plant so it gets good air circulation.  The plant should also be in a pot that has a drainage hole, so excess water can flow out – it does not like wet feet. The humidifier may make the discolourations/spots worse, if excessive moisture/humidity is the culprit.  I’d suggest that you turn off the humidifier for a few weeks and watch to see how the plant responds.  If the symptoms resolve, keep the humidifier off, if the leaves dry and curl, turn it on again.     It should also be placed in an area of the house where it gets lots of bright, indirect light.”

All the best with your bird of paradise!

May 13, 2021