Spider Mites

[Charlie]

Good question, Laura!

Diatomaceous earth has a lot of word of mouth supporters and is sold as an organic pesticide but I haven't found any university or industry studies of its use in horticulture. I have not tried it in the HVH greenhouse or our garden but I like the idea of it.

In theory this material pierces the coating of many insects, and its ability to attract moisture hastens the loss of water by insects that are wounded by its sharp edges, thus causing them to die of dehydration. That means that for it to work an insect, mite, slug, ant or what have you must come into direct contact with the substance. Since it is a powder it is easiest to use applied to the surface of the soil or potting mix around plants. Doing that would not help much with spider mites since they do not travel from plant to plant by walking over the soil surface.

DE could be sprinkled on leaves which might do some good. But, mites feed on the underside of leaves and spend most of their time on the undersides so once again it seems to me that they would not come into contact with the DE easily.

I hope someone will try DE on or around their hibiscus and let us know if they get some benefit. The material is almost pure silica which will not hurt the plants and actually is beneficial as a nutrient.

Anyone with more experience with DE? 

Charlie

[blupit007]

Hello all,
  I'm new in the neighborhood, and unfortunately this has to be my first post   First of all I have 3 beautiful plants that I just got from HVH, Saffron is a blooming champ!!  My profile photo is with its first bloom, its yellow because it budded in the transit box across country to get to me, but it is 10"!! 

  I have a Belle du Jour with seriously yellowing leaves that keep getting worse no matter what insecticide application I use.  I have Neemed, Used 30 day Bayer Rose & Flower insect killer, and water blasted it!!!  I have a couple other plants that are starting to yellow too.  I just looked under Belle's leaves and saw the little monsters moving around with a magnifying glass. 

  I don't understand.  I have applied enough bug spray to kill a cow!  Why are these still here??  I don't want to loose Belle!  Saffron & Cindy's heart is happy and healthy.  Cajun Blue is starting to yellow and so is my tiny Gabriel. 

  Please help me...  Do I dunk them?  I don't know this method, as I am new to the tropical hybrids.  I posted photos for you to see, the yellow arrow is pointing to one bug that is crawling around.

Thanks,
Kristen

[Charlie]

Hi Kristen, welcome to the neighborhood! Great photo of that big Saffron bloom.

The reason that the spray is not getting rid of the spider mites is that mites are not insects and are not affected by normal insecticides. What you can use to get rid of them is horticultural oil. This is a highly refined, lightweight oil that smothers the mites. You can find some at a local garden center or we have it in our online store, too. I would not recommend waiting though, the sooner you can get the oil and spray every surface of the plants with it the better it will be for the hibiscus. There are special "miticides" that work on mites in a chemical way but they are for commercial growers and usually you have to have a permit to buy them. The oil works almost as well.

Caution - use the oil in the evening or on an overcast day and keep the plant out of direct sun for a full day after using. Actually, you can use it any time if you move the hibiscus into the shade first. It is critical to cover every surface of the plant, most importantly the undersides of the leaves where the mites feed.

You will find other techniques here and there on this forum, most of them being variations on washing the plants by submerging them in water. This works, too, but is a bit messy for my taste. My wife likes to do it on her smallest plants but I prefer spraying with oil. You may have to do it every 3-4 days for a couple of weeks to be sure all the mites are gone. Then try to make sure the hibiscus are not touching each other so that any mites that come along can't spread quickly to other plants.

One last tip - any leaves that have started to turn yellow are going to fall off soon, whether treated or not, so it is a good idea to remove them right away because the mites that are on them will not be able to spread to other leaves if you get rid of the infested leaves. Don't worry, in summer new leaves grow back quickly.

Keep us posted.

Charlie

[Cindy]

Oh no, Kristen!  Not the week before your wedding!!!!!!  If I were you, I would just haul them all into your bathtub, fill the tub up with warm water, leave them completely submerged for 45 minutes, then drain out the water, stand them up to drain, and your spider mites will be gone all at once. It does make a huge mess in the bathtub, but it kills the mites immediately. A couple of warnings though:'

1) Clean up well all around the area where the plants were!  Spider mites can hang out on walls, windows, in grass, etc. Hose down grass or patios really, really well. Spray window cleaner all over walls, windows, window sills, etc and clean them really well.

2) Bathe ALL your plants, even the ones that show no signs of spider mites. All it takes is one mama bug that climbed onto one clean plant to start the whole cycle all over again.

3) Wash your watering can and any trays you stand your pots in too.

If you use warm water, like for a baby's bath, you won't get yellow leaves afterward, and even buds won't drop sometimes.  Hot water will make the leaves yellow and buds drop for sure, so I like to use only warm water now.

If you need more help, just holler!
Cindy

[Darkhorse]

Charlie covered it but I just wanted to add that I have been having fantastic results with the horticultural oil.  Just make sure you don't spray the concentrate directly on the leaves... use the diluted version, whether it be from a garden hose or the ready to spray bottle.  One would think this would be common sense but... ahem... some people have done it.  

If you only have a few plants too go ahead and treat all of them at once.  There could be mites on Saffron and Cindy's Heart that you haven't seen yet.  To completely eradicate an infestation I find that it's best to treat everyone with or without symptoms.  This is especially important if your plants are indoors or in a location where space is limited and they are close together.  If you've touched an infested plant and then another, chances are you've already spread the mites that way as well.  Finally, cleaning the area around the plants is important too, or the mites that have fallen off the plant could just crawl right back on.

[blupit007]

Thank you all so much for your help.  I don't know which method to use.  Belle du Jour is in a 2 gallon pot, so bathing her might be a big job.  Maybe I bath everyone else, and use the "All Seasons Horticultural & Dormant Spray Oil"  that I have.  Dilute it in a spray bottle as listed on the bottle, and spray the big ones...

[helixturnhelix]

My Belle is dealing with the same problem and man do mites just love Belle!  I have had the hardest time getting rid of mites on her, she is even outside and they are attacking her like crazy.  I am hoping that some beneficial insects show up soon, the hot water dunking is not enough for this infestation!

[blupit007]

So, because I had an hour to shower and get to work (I bartend) I decided to mix up the oil I mentioned before and spray everyone.  I moved everyone into the shade and sprayed all over.  I hope I got the liquid measurements right.  I have a 32 oz spray bottle.  The recommendation is for 2.5-4 Tbsp oil to one gallon water.  I used 1.5 Tbsp for the 32oz bottle.  I'm really horrible at math.  Do you think I should do the big dunk tomorrow morning too??  I also scrubbed the areas where they live with a scrub brush and dish soap.  The only place that is difficult is behind Belle, there is a screen.  I did a quick spray and a run over with the scrub brush, but not much.  UGGG!!! 

On a happier note, here is a pretty photo of the best hibiscus on earth who bloomed again yesterday.  Safron! Thanks Cindy & Charlie for finding it for me last month.  You rock.  Now I want Vin Extraordnair and Confection Perfection after looking at the June forum!

Thanks everyone,
Kristen

[Charlie]

Kristen, that's about as perfect a Saffron bloom as you can get. Very nice photo!

Belle du Jour for some unknown reason is very attractive to spider mites in our greenhouse. I go out of the way to spray them weekly even when they don't appear to need it. However, the interesting thing to me is that the 4 plants of Belle that are in our garden don't have any problems with spider mites. I can only conclude that predator insects that feed on mites are also attracted to this variety and take care of this problem in the garden.

Sometimes it's not the variety but the age of the plant that makes spider mites more of a problem. Older plants develop many craggy places on the hard bark for insects to hide in and it can be more difficult to cover all these places with spray. Not impossible, just harder.

The oil/water mix you made is a little strong - equivalent to 6 tablespoons of oil per gallon of water - but should be OK as long as the plant was not left in direct sun. One tablespoon per 32 ounce spray bottle will give you the  rate of 4 tablespoons per gallon that is within what the manufacturer is recommending.

At worse you might get some yellowing of leaves from the rate used, but there are already plenty of those from the mites. New leaves will grow in soon so don't worry about the leaf loss. This fine grade of oil evaporates during the day and you probably won't even be able to see it tomorrow. For best results plan on spraying the plant again on Sunday. For sure clean out any fallen leaves or other loose stuff that may be around the base of the plant and on top of the soil. Mites and mite eggs could be in the debris so cleaning out the pot is an important step.

Good luck and let us know how it goes!

Charlie

[blupit007]

I got confused with the math.  I sprayed everyone, even Saffron and Cindy's Heart who aren't showing any signs of bugs.  I put them all in the shade yesterday morning and left them there for a day and 1/2 until just now (midnight).  There leaves are all shiny and pretty that's for sure.  I cleaned the area around them too. 

Belle looks to be an older plant.  I just got her about 3-4 weeks ago from you in a 2 gallon pot.  She has been cut back a bit and has all new growth growing from her almost 2" base!  But she is only about 2.5' tall. 

Question, I use the entire mixture of fertilizers you suggest once a week, booster, Super nova, HVH special fertilizer, peroxide, & soap...  Saffron and Cindy's Heart look amazing!  There leaves are HUGE, shiny & deep green.  But I only got Cindy to bloom twice and they didn't last more then a day.  Saffron seemed to slow a bit too, Belle only gave me one bloom.  Am I doing something wrong with the fertilizer?

Thanks for all your help!  I love your Forums!  They are great and so helpful to a newbie like me!!
Kristen

[Charlie]

Hi Kristen,

The Belle du Jour is an older plant - probably her 3rd summer now which is why the base of the main stem is so thick. She was cut back hard last spring which is why she is not very tall yet. Also, this plant needs to be repotted. Over time soil is leached from pots and there is less volume of roots and these older plants often have much less soil in them than when they were first planted. Roots are needed to get the best growth and blooming - many hormones are manufactured in the roots so healthy roots and plenty of them give us the best performing hibiscus.

You can either take the plant out of the pot and add a good potting mix to the bottom and then place the hibiscus back in the same pot, or you can repot into a new and slightly larger pot. Either way will provide room for the roots to grow and the stems of Belle will grow a lot, too. However, due to the spider mite attack you should wait until that quiets down and you see a little new growth coming on the plant. You can send us a photo of the bush if you are in doubt about whether it is ready for repotting.

Your fertilizer program sounds good, as long as the proportions are within a normal range.

When you say the leaves are huge that suggests to me that the plants are not in a lot of sun. Many hibiscus hybrids have larger leaves than their older relatives but lower light levels tell the plants to grow larger leaves so that they can gather in as much light as possible. If your hibiscus are in lower light (compared to full all day sun) this would also explain a slowing down of blooms. Hibiscus like conditions that stay the same day after day and will perform best after being in one location for awhile so that they adapt well to those conditions. Your plants are still adapting but you will get the best results for the rest of this summer if you put them in bright conditions and leave them there until fall forces them indoors.

Cindy's Heart flowers last much more than one day so that is a concern. If you can, post a photo of the one you have so I can see the leaves well. Also check the bottom of the stem to see if you can see where it was grafted (it might not have been but I'd like to know). Hopefully one day bloom was just a fluke due to changes in environment or something like that.

One last thing to watch for is bud drop. If the hibiscus are making buds but the buds fall off before opening that is completely different than if the plants are not making new buds at all.

Good luck with the next step in your hibiscus adventure!

Charlie

[helixturnhelix]

Hey Kristen,

My Cindy's Heart is having issues opening flowers too, I had one open in the box and it lasted a day after it was out.  I didnt know when it bloomed so it could have been open longer.  All of her new buds keep turning yellow and falling off, I sprayed for thrips using Bayer, but still yellowing buds.  Its frustrating because all the other plants do not have this problem.  Any ideas as to why this is happening? 

 

[Pachrian]

Chris, my P's Purple dropped a few buds yesterday too. I opened one of them and look what I found It's about 4mm long, all stretched out.

Did you open yours to see if anything was crawling inside?

[Darkhorse]

UGH I need to vent, I just found mites on my Black Dragon today.  I've been having some minor infestation issues due to a few plants coming in with mites, but now that it has been hot the population is exploding!!!  Anyway with the spacing between my plants the mite spreading must be coming from my fingers.  Guess I'm not very good at keeping my hands to myself.   

Anyway my goal is to have the mites eliminated again before this winter when I have to bring all the plants in the house.  They'll be living in very close quarters again at that time.  Until then horticultural oil every three days in the evenings.  A plus side is the hose end bottle lasts forever! 




Kristen and Chris about the bud drop/short bloom time...


Chris, any chance the bud drop could be from shipping stress?  I've had small buds yellow and drop as late as 2 weeks after shipping.  Did you just get the plant in the mail recently?


Kristen, same goes for your short bloom time.  I've noticed that it takes a good month or so for the plant to be blooming in the same location for bloom time to become ideal.  I don't know if your plants are outdoors or if its hot where you are but that can have something to do with shorter bloom time too.  Heat speeds up all metabolic processes, so buds develop faster.  Unfortunately this also can mean shorter bloom duration.  This is what I've seen, anyway.  My Confection Perfection opened yesterday (while I was at work grr) and said nope, too hot!  It was closed before I got home last night.
 

[helixturnhelix]

Hey Jordan,

Its been about three weeks since I got it (I think) All the small buds are intact and growing, but when they get a certain size they turn a bit yellow.  I thought it was thrips, but I just treated for them.  We will see if the next batch turns yellow or not. 

As far as spidermites are concerned, the mites can catch the wind and get deposited on your plants.  Is it windy and dusty where you are?  The other possibility is they are riding on your hands.  This might seem a bit drastic, but I use the waterless hand sanitizer when I am working between plants.  I think the alcohol in the sanitizer kills the mites you get on your hands and I haven't had any spread since I started doing that.  Also, since you have a hose you could wash under the leaves of all your plants, I wash under the leaves twice a week   This should clean out dust and any possible mite colonies before they get bad.  Hope this helps