shimpaku with dying tips! please help!

[pspees]

Hello there, new to the forum and am glad to be here! Okay so my problem is with one of my junipers; it's a shimpaku and has recently started to brown at some of the tips. It's not a serious problem (yet) but I would like to get this taken care of asap. I read a lot about this and most of what I can come up with is that it's either a watering problem or some kind of pest or disease. What do you think?? Any help is greatly appreciated, thanks!!

 

[Brian Van Fleet]

It's probably from overwatering. Though it's tough to diagnose other than through a process of elimination...with junipers my process is like this:

Spider mites?
Caterpillars?
Foliage staying wet overnight?
Soil too wet?

Nothing can be done for the tips that have browned, twist them off. Then see if you can identify the cause and correct it from getting worse. Shimps are tough, and from the photos, yours looks pretty healthy otherwise.

 

[Defect]

If you wouldn't mind me asking, what are you using for soil? I can't really tell from the picture. I had a shimp of mine get a little yellowing earlier this year but I chalked it up to being recently moved into more sun and seems to be doing great now.

 

[pspees]

I'm not so sure about the soil. It's the same soil the tree was in when I bought it and it seems to be of good quality and drains well. I'm weary of repotting right now as this is the hottest time of year here in San Diego. I do want to repot but I think I'll wait on that. I have been fertalizing this one every couple of weeks lately. Should I hold off? The tree seems to be doing fine with feeding but I don't know if it's too week to do this or not. No mites or caterpillars as far as I can tell. I did find one mite and one tiny caterpillar by shaking all of the branches. I don't know how bad that is but it doesn't seem like an infestation to me. As far as foliage staying wet over night, I mist it every other night and the foliage does stay wet most of the night. Is this bad? Also, I have been watering more frequently due to the heat. Hope this helps!

 

[Defect]

I would probably stop the misting at night. I didn't really know that keeping the foliage wet over night would cause that but I would believe Brian. Water when the soil starts to dry a bit, check it with a toothpick or a chopstick to see if its drying. Definitely do not repot right now.

 

[xray360]

Do you keep it outside?

 

[pspees]

Of course!

 

[fore]

Well I had a bad spell earlier this yr of tip blight that hit fast and hard on a yew, larch and shimpaku. Lost the yew. Here's some info: http://www.mortonarb.org/tree-plant-advice/article/725/juniper-tip-blight.html

Just something to keep an eye on.

 

[pspees]

I started watering less but I don't want to let my trees dry out too much. What would be a good indicator of when to water? Also, the roots are pretty crowded in the pot so I want to do a re-pot. Should I just wait until next spring or will that be too long? I have another juniper that I re-potted last spring that's doing stellar now but before that it was dying back from being too root-bound.

 

[xray360]

I started watering less but I don't want to let my trees dry out too much. What would be a good indicator of when to water? Also, the roots are pretty crowded in the pot so I want to do a re-pot. Should I just wait until next spring or will that be too long? I have another juniper that I re-potted last spring that's doing stellar now but before that it was dying back from being too root-bound.

I recently repotted a root bound juniper end of july. I didn't do any root work on it, just loosened it up and put it in a bigger pot. It's starting to regain vigor again. On http://bonsai4me.com/SpeciesGuide/Juniperus.html they talk about how you can successfully repot junipers in humid days of August. Don't repot on a dry hot day. This also depends where you live. Also looking at the soil it's in, it looks very sodden on the first picture. Junipers like gritty mixes.

 

[pspees]

Thanks for the info! I'm not going to repot now seeing that it's been really hot (90's) here in San Diego and usually stays that way through October and even into November sometimes. Maybe a late fall re-pot would be ideal?

 

[Sekibonsai]

You want it to be evenly moist but not soggy- it will take checking once to twice a day till you get it figured out- even then you can get a weird set of conditions where it will dry out unexpectedly. Also, I learned from a highly skilled friend a few weeks ago that he keeps his shaded- as compared to others like san jose that he can keep in full blazing sun. I moved mine out of the full afternoon sun and they are doing much better now- stronger growth on the tips...

 

[xray360]

Thanks for the info! I'm not going to repot now seeing that it's been really hot (90's) here in San Diego and usually stays that way through October and even into November sometimes. Maybe a late fall re-pot would be ideal?

Read this page about repotting http://www.kaizenbonsai.com/shop/repotting_guide.php#Recommendations_for_re-potting_evergreen_bonsai

and this one is good too for fall repotting http://www.evergreengardenworks.com/fallpot.htm

If you have mild winter that aren't too cold you could repot in fall. If you get freezing temperature and a lot of snow, best to wait till spring. But like sekibonsai said, just make sure the soil is moist. I usually wait till the top is a little dry and then water it till it comes out of the drainage holes. That usually lasts a full day.

 

[rock]

If you get freezing temperature and a lot of snow, .

Ha ha good one...ever heard of Sandy Eggo, hasnt even been a frost here in the last 10,000 years.

The epitome of mild winter. So.

Your tree looks fine, knock off the browning, keep it in full sun for tightest growth. Water every day now until holloween,

And go to SDBC, for more tips !

www.sandiegobonsaiclub.com

 

[milehigh_7]

Read this page about repotting http://www.kaizenbonsai.com/shop/repotting_guide.php#Recommendations_for_re-potting_evergreen_bonsai

Graham is awesome but he is in the UK and could not be further from your climate in SD. You got great advice to hit up your local club.

 

[pspees]

So it's been about a little over a week since I started watering less and stopped misting heavily at night and the problem with tips browning off continues...
The tree does have mites as I have found since I checked it again. I found about 10 this time when I did the sheet of paper trick.
I also found a few tiny caterpillars and what appeared to be a little egg sac on a couple of the needles. So...
I'm just confused now as to what I should do. I really think that the tree should be repotted but it's probably too weak right now and it might be a long time before it livens back up. As far as pests go, what should be done about the mites/caterpillars? How do these little bugs damage a tree?

 

[Bill S]

You don't want to repot a tree that is stressed, unless absolutely necessary, this case isn't. Also a week isn't long for a tree

 

[Vance Wood]

I probably have a dozen or more Shimpakus ranging in sizes from six inches or less to twenty-four inches and more. I have seen this problem come and go on trees that are treated more or less the same and it always goes away. Sometimes it helps to move the tree into a more shaded location for a week or two. I think a good portion of the issue is more one of heat than anything else, I would put water next but there seems to be no one solution I know of.

I do have a question for some of you Shimp masters: Have you ever seen scale on a Shimpaku and what does it look like.

 

[Eric Schrader]

In regards to getting rid of spider mites:

Try an oil spray first - they are like microscopic aphids and they suck sap from the tree. If you only have a couple small trees then you should be able to saturate them with an oil spray. The good thing about oil is that it suffocates the insects - so they can't really develop resistance to it. If you have more trees or the oil spray doesn't get rid of them then switch to malathion, orthonex or bayer shrub and tree care, or look for a specific miticide. Those are systemic chemicals which the tree will metabolize and then when the mites such sap it will kill them. Spider mites have about a 10-day life cycle so you need to re-spray the tree two more times at ten day intervals to catch mites that are hatching after you sprayed. Alternating with two or even three insecticides helps ensure that the mites don't build resistance. Make sure you spray everything that you have, not just the infected tree. They are wind blown and can easily re-infect a tree. If you have large conifers like Italian Cypress, pine or similar in your neighborhood that are infected you will have an ongoing problem.

Overhead watering with a good spray of water discourages small infestations from getting large by washing them off the plant, but once they get established the water method doesn't work. I would recommend that you overhead water your tree at least a couple times a week, not misting, but a good overhead spray to rinse things off.

regarding Shimpaku and scale - I've seen small white scale infect shimpaku. They're not particularly damaging to the trees in my experience, they usually attach the weaker growth and shaded areas. They look like little spots of sap. If you flick the branch you might see small white flakes fall off. The same type infects procumbens and it seems to prefer procumbens but it generally only weakens branches a little, it doesn't kill them like spider mites do (at least in my experience.)

 

[jk_lewis]

A HARD jet of water into the foliage will get rid of the spider mites. You may have gotten them when you stopped misting, as they don't like moisture around them.

Your foliage looks pretty normal to me. The little brown I saw looks as if it might be the result of zealous prinching or cutting back of the growing tips.