Why does my Dracaena fragrans lose its leaves?

Question

Almost a year ago I bought a Dracaena fragrans plant of 2 meter in height which has since lost a lot of its leaves. The plant often loses leaves in a certain process. Every time a leaf is going to turn brown, it develops one or more yellow or brown marks in the middle of the leaf which are eventually connected until the leave has completely turned brown.

These are photos of three different leaves in different stages of this process. Additionally, many leaves at the bottom side of the plant look limp. As you can also see in the picture, one branch completely or partially turned dark brown. About 3 out of 10-15 branches turned brown like that one.

My apartment views the west, so in the summer on sunny days, the plant receives direct sunlight in the evening for a couple of hours at most. Recently I experimented by putting the plant outside in full sunlight, but that only burnt the plant so at the end of that day I had to remove about 15 leaves which had been scorched. Apparently lack of sunlight is not the problem.

Location: the Netherlands.

The plant does not look very healthy and I estimate that it has lost half of its leaves in the past year. What could be a typical cause of these brown and limp leaves?

Answer 1

I have seen these symptoms on hundreds of Dracaena grown indoors. There are some common factors:

• too much water makes the soil consistently wet. Leaving the plant sitting in water does the same thing.
• overwatering encourages fungus/virus/bacteria which is what is making the spots on the leaves.
• a soil less mix will degrade over time as the organic material is used up. It then compacts and drains poorly.
• in areas where the water is alkaline (pH 7 and greater) over time this affects the pH of the soil. This affects the uptake of the iron/manganese micronutrients which weakens the plant.

On another note if you move a plant from inside to outside the chloroplasts are not able to adapt to the hundred or thousand fold increase in light levels. The leaves burn as you found. Many tropicals can benefit from a stay outside if they are moved to deep shade, then light shade, then full sun over a period of weeks. See more about hardening off here.

To resolve this problem I recommend:

• repot the plant. You can use the same pot but put fresh indoor planting mix in the bottom third of the pot. Use this opportunity to examine the existing roots which should be firm and white or with a yellowish tinge. Soft and black roots are dead and should be cut off.
• the stems are very closely planted together. If they are not too grown together move them apart
• water less: at least the top inch of soil must be dry before you apply enough water for it to run out of the bottom. A seven to ten day cycle is common.

I favour the tough love approach to tropicals. Your plant has a well entrenched fungus/virus/bacteria which it can outgrow. Consider removing all the leaves and cutting back the stems after repotting. Cut back on the water and wait for new buds on the stems. These plants bud out readily from old stems, it just takes some time.