The plant looked nice in the store, but now the leaves are turning brown. Help!

“Mandevilla is cold sensitive and can be taken outdoors when the danger of frost has passed and overnight temperatures reach over 50ºF. It likes full sun to part shade in the summer and a deep rich, well-drained soil. It will also need a trellis to support its long trailing vines. Provide plenty of water during the hot days of summer. To keep a healthy blooming plant, feed it every other week with a high phosphorus fertilizer (10–20-10) in the spring and summer. In order to maintain the tangled growth during the season, pinch off new shoot tips which will produce a bushier plant. Trimming will not reduce flowering as it blooms on new growth. Use the cuttings to make new plants.”

From here

My guess would be that you need to re-pot into a larger container. The small pots that they are shipped in is not enough room to grow in the luxuriant manner that mandevillas are capable of.

Leaves turning brown means the plant is getting too much water.

Unfortunately, sometimes when we overwater it’s too late even if we cut back the watering at the first signs because root rot has already set in.

Allow it to completely dry out and it may have a chance of recovery. Make sure it’s got good drainage out the bottom of the pot. You can do this by sticking a stick or pencil (whatever will fit) into the drainage holes and piercing into the soil from beneath and then also from the top.

In my par of he world, it’s frost damage. We snow 2 weeks ago and frost he nex few nighs.

MagicalMystery, strange as it may seem your mandevilla may not be getting water to its roots! In Australia a lot of the “potting mix” that plant growers use is fairly useless at retaining water, and after a while the root ball completely dries up. The answer, IF this is the problem is to half-fill a bucket with water, then gently put the pot into the water until the water covers the top of the plant pot by, say, one inch. IF you see bubbles coming from the pot, THEN your plant’s root ball has dried out, despite your watering it. Remove the pot from the water when the bubbles stop, and allow it to drain. Your plant now has a good chance of survival.

IF no bubbles come from the pot, THEN it is not a matter of the plant having a dry root ball.

I really hope this helps, and I wish you all success. Let us know how it goes. I wish to hear your results.

Andreas

I’m the kind of person that like making stuff simple, so simply, : Place them in water and add an excess of sugar and a pinch of salt. There, that should work, sugar is known to revive plants. Hope it works!