I bought a yucca tree about a year ago. It lives inside close to a large window and gets a few hours of full sun a day. Right now it's outside on the patio because it's soil is full of flies...but that's another problem The real issue is this. The leaves are limp, curly, and have either a brown rusty substance on them or a white powdery one. I am about ready to toss it off the balcony! Please Help! Oh, and it's not possible that this is due to over watering. This plant is definitely underwatered. The soil is a nice light sandy mix too...
if the leaves that are browning are the lowermost leaves, i wouldn't worry - just the natural growth pattern...older leaves die off as new ones appear at the top. yucca like very dry conditions. sand retains quite a bit of moisture, so it's possible there is some rot happening with the roots - even if the container has drainage holes. if there is rot, the plant is stressed and will be more susceptible to attacks by insects and fungal/bacterial agents. the extra moisture would give fungus gnats just the conditions they like to grow in, too. when did you put it outside and did you ease it into the brighter sunlight and different temp or did you just put it out and leave it? if you didn't ease it into the different situation, it could be in shock and it also may be too cold at night and that may be causing issue as well. much higher sunlight, all of a sudden, can cause leaf burn and/or leaf bleaching. the third pic does look like you've got some kind of fungal attack happening - looks like rust, maybe. the white stuff could be mildew - doesn't look like mealy bugs...although, they are another strong possibility of being an issue (could be juveniles which look a little different than the full-grown). if the plant was in good shape (other than the flies in the soil) before you put it outside, i'd say the outside conditions are not good and are causing the white stuff and the rusty-colored stuff. and i'd recommend putting it back inside in it's previous location until it's on better footing.
Hi! Thanks for the reply! I just put it outside 2 days ago...and it's in about the same amount of sun. I just stuck it outside due to all the little flies in the soil. The condition of the plant has remained about the same for the last 6 months or so. If it is rust and mildew how should I treat it? Also...should I trim the bottom leaves as they brown?
if the browning of the leaves really bothers you, yes, you can trim them. i usually just leave them be until the whole thing is brown/dry and then a gentle pull and the whole thing comes off. when was the last time it was repotted?? does the container have drainage holes? if you've not repotted it since you bought it, then i'd suggest doing that (now's the right to do it, too). if it's in the original soil - which is probably peat and not real soil - then that could be what's causing the some of the issues. other than treating with chemicals, the only way to get rid of fungas gnats is to let the soil thoroughly dry out (so that the eggs dry up) or replace it with new stuff. if the plant is in peat, you don't want to allow that to completely dry out because, once it does, it's like rock. so, best to get the plant out of it asap. when you unpot, remove as much of the peat from around the roots as is possible. shake it away (over newspaper or outside if you can) and then either submerge the roots in a bucket of water to moisten the peat and then swish it around to remove it or use a hose to remove the peat - don't use too forceful a spray, though, as you don't want to damage the roots. if any roots are brown/black and/or mushy cut them away. if the roots are bound up, repot in a slightly larger container. the root ball should have about an inch or so of space between it and the edge of the container. cactus mix with some additional perlite added in is a good growing medium for dracs.
Thanks again for the help! I repotted it about 2 months ago in a soil/peat/sand mixture. But I might take your advice and repot again (in the same pot, different soil). The soil I used seems very crappy. It was a miracle grow soil...and full of large chunks of bark and bits of plastic??? weird. Cactus mix it is! I trimmed the brown leaves last night and washed all the other leaves down with an insecticidal soap.
ahh, miracle grow stuff always has fertilizer in it...that, almost always, is a problem for the plants (can burn the roots and most succulents, like yucca, rarely need fertilizing)!! also, for yucca, peat and sand are both water-retaining and yucca love to have dry soil. yes, definitely repot it!! i'd allow it to sit in the new soil, unwatered, for at least a week...then do a thorough watering and then water again when the first couple inches of soil are very dry.
glad to help!!! these are pretty hardy - i'm sure it'll be back in its glory in no time :) and you MUST post an updated pic when it is!!
