Thursday, June 23, 2011

Question for the Hive Mind: Is it cyclamen mites?

How does everyone feel about an afternoon post that isn't related to Lady Gaga?

I said on Monday that I've been having some weird things going on with my Saintpaulias, and suspected cyclamen mites. It's possible that I'm so anxious to get rid of the Saintpaulias -- and I am highly motivated either to make them shape up or to make them go away -- that I'm leaping to the worst possible conclusion, though. It's not like I have first-hand experience with cyclamen mites.

So I present the readership with the best images of the situation I was able to get. They're still not very clear, but I'm working from the assumption that people who have experienced African violet problems first-hand will recognize what's going on even if they're not the best pictures.

So. Photos will enlarge considerably if opened in a separate window.

New leaves are various combinations of cupped, stunted, and twisted.

Scarred leaf in the lower right; new leaves slightly wavy/twisted.

Stunted and twisted leaves, mildew or something resembling mildew, widespread tan scarring on one leaf.

I should also mention that one of my plants did a thing where the growing tip, and all the developing leaves, seemed to die all at once last winter, leaving a bare little nub surrounded by old leaves. This isn't necessarily related, but since I don't know what's related and what's not, I'll mention it. (Apologies for not having a photo; I thought of it too late in the post-writing process.)


Care history, if necessary:

Affected plants have been at least 65F/18C the whole time, save for possible occasional brief blasts of colder air last winter when they were in the plant room (they were sort of close to a door, though they were far from any windows or drafts, and there were other plants between them and the door). They were moved a while ago to the living room, which is perhaps still colder than they'd like, but it's 72-74F/22-23C in there around the clock, as far as I'm aware.

Light in the plant room was mainly supplied by a desk lamp with a compact fluorescent bulb in it, though they were on a metal table, and got some indirect and a little bit of direct sunlight on days when we had sunlight. In the living room, they're on shelves in front of a large, unobstructed east window.

I have changed the soil since noticing the problem, but when it started, I was still growing them in the soil they were in when I bought them. (Not to bias the opinions, but one expert suggested by e-mail that the soil was the likely cause for the one that dropped all the new leaves and left nubs.)

I'm not great at keeping them watered, at least not considering what they'd prefer. They do dry out pretty regularly, and always have. They never stand in water for long periods of time, though I do water them from the bottom by standing them in saucers for short periods. I have been able to keep one plant going and blooming for two and a half years, though, with similar treatment, so it can't be too far from what they'd like.

I've used different fertilizers at different times; 14-14-14 Osmocote w/o trace elements for the first couple months, then 24-8-16 Miracle Gro with trace elements for the last four months. The problems started at about the point where I began using the Miracle Gro (Februaryish), though I think that's coincidental: the long-lived, established plant hasn't shown any changes since I switched fertilizers.

Humidity level is higher than the average home, but variable enough that I can't provide actual percentages. Air circulation in both locations has been fairly strong (ceiling fans).

I have never seen bugs of any kind on them, and I at least know what mealybugs and aphids look like on African violets.


Sentient Meat said...

Yes, I think I had a thread-footed mite infestation (of my cyclamens) -- either broad mite or cyclamen mite -- and the damage reminded me of this. Unlike spider mites, these mites are nearly invisible to the naked eye, and show up mainly in their damage, especially to new leaves and flowers. I controlled mine using a large pot and a thermometer, dipping my plants one by one in a bath at some precise temperature... 113 degrees? something like that I got off the interwebs. I used cheescloth to stabilize the plants and medium in their containers. It was annoying, but in my case, it worked.

Tom said...

I just threw away a plant that was doing something pretty similar. I decided that it probably was cyclamen mites. I can't tell you for sure though. My vote is pitch it, you don't seem horribly attached to it and African violets are a dime a dozen anyways. You can always propagate a leaf if you're super attached to that particular plant for some reason.

Anonymous said...

Yes, that definitely looks like broad or cyclamen mite. They're both pretty bad and have similar effects. It's much easier to throw the violets away, especially considering that if you make a mistake with the hot water method, they will come right back. Whatever you do, make sure to clean everything with clorox after you deal with the plants to prevent the mites from hanging around. As far as your watering goes, making a wick watering system is a breeze, and keeps you from having to water the African Violets often. I use little Glad tupperware containers and just cut a hole on the top lid and slide the AV in it's pot right in. For the wick I use ACRYLIC mason line, not a cotton material because that rots, and for the soil I just mix half basic potting soil, half perlite. There are plants that will host Cyclamen mite even though they aren't hurt by them, so it's best to work with your African Violets BEFORE all the other plants, so that pests don't spread from host plants. There is a good video on wick watering at the blog.

Paul said...

Another vote for "pitch the plants". As has been noted, AVs are cheap. Get a new plant or two or get a couple of leaves to start anew.

Btw, I find AVs grow very well in terrariums.