Hello-

About 6-8 weeks ago I brought this potted dipladenia indoors after having it outdoors here in Michigan all summer.

I've placed it with several other plants in a sunroom where it gets lots of light from skylights and large wall windows.
I added a couple supplemental fluorescent lamps for it as well to compensate for days with little sunshine. I keep the thermostat at 62-64 degrees F most days.

Its done quite well since coming inside, hasn't dropped any leaves & even grown a few more. I've been unsure how much to water it. I understand it should be watered less in the off season however it's getting lots of light & is probably pretty pot bound. It never feels very wet, even just after watering. I've been watering it thoroughly about once a week as opposed to about once per day when it was outside.

All was good until I noticed a few mealy bugs appearing a couple days ago. I removed the plant, sprayed it thoroughly for the pests & isolated it, at least temporarily, to a bedroom with a west facing window with the fluorescent lamps until I'm sure mealy bugs are gone.


My questions - Is there something I can do to reduce the likelihood of another mealy bug attack? Is this plant just more susceptible to pests when brought into indoor environment? Is there something with my watering routine that has contributed to the problem? I want to be sure I don't put other plants at risk by moving it back to the sunroom too soon.

I've included 2 photos here : 1) before I brought it indoors 6-8 was ago and 2) yesterday after treating for mealy bugs & isolating it in a bedroom.

Thanks very much reading & for any advice you may have.😊

Abby, you need to treat the plant probably two or three times (better) within a week to be sure to get all the mealy bugs. New eggs hatch and the tiny nymphs hide in the leaf axils so if you only treat once, you almost always have a re-infestation quite soon.

Use a spray of 1/2 rubbing alcohol diluted with water. Spray very thoroughly - everything dripping - each time. Stems, undersides of leaves, soil surface, everything.

Your plant may go dormant in response to the short days even if the weather remains sunny. Your sun room sounds like an ideal winter home for this plant, though. In spring when you see new growth starting, you should probably invest in a larger pot, fresh potting soil and get that baby into more room for next summer. Your watering chore will be a lot less with a big enough pot. I always recommend you choose one that is a light color, which helps keep the roots of the plant cooler if the sun shines on the pot.

Hi Elaine- thanks for replying. 😊 I'll get more rubbing alcohol and get on that. Do you know are mealy bugs more likely to be a problem when this plant is grown indoors? Haven't had any pests problem when they're outside.

I really don't know, Abby. Mine all stay outdoors all year round.

It's possible you have a predatory bug outside that takes care of the mealies for you. Also the cold would kill them off on plants that are left outside.

I think just bringing a plant indoors after a luxurious summer outdoors in the humidity and natural light stresses it. Any stresed plant will be more susceptible to pests which seem to appear out of tin air. Like Elaine said, it may well lose its leaves and go dormant. I would still take it into the shower once in a while and give it a good spray all over and do use the alcohol mix every now and then as she directed.

Any plant under stress for any reason will be more susceptible to plant pests. Moving a plant from the near-ideal conditions of outdoors to the less than ideal conditions indoors will stress a plant, especially if it is not given maximum indoor light and the watering routine is not adjusted appropriately.

Add some liquid dish soap to the alcohol/water mix. That will help the solution spread over the entire plant and penetrate the leaf axils more readily. Repeat treatments are only necessary if you fail to get complete and thorough coverage of all leaf and stem surfaces.

After flowering and moving it indoors, it is a good time to prune it back as much as you can stand. Pruning first will make spray treatment that much easier.

Many thanks everyone! 😊

I have found that lack of air movement indoors encourages pests, also. I have a lot fewer pest issues with a fan running in my small greenhouse.

Good idea Carol.

It's something most of don't think about, but for whatever reason, that seems to make a big difference. Learned that on the orchids forum!

I do that now in my greenhouse, and it does cut down on the insect problems.

Me too, I have a fan on a timer in the cage, turns on at about 2pm and runs until 5-ish.

I've definitely noticed a reduction in thrips damage since I started running it regularly.

Makes sense. Plants grown in ideal conditions rarely have pest problems.

I'd never heard that about air movement but adding a fan for part of the day sounds like a good idea.👍🏻