Spider Mite Infestation & Seeking Solution

I've been gardening about 5 years, but only been serious about it for the last 2 years. Last summer was the 1st time I realized what spider mites are and the damage they cause. Only my potted roses were affected in the past outside during summer, and my Colocasia & Sweet Potato vine infected this past winter after bringing them inside. Thankfully, I caught them before they could do too much damage.

However, this spring life for my outdoor ornamentals has been traumatized by spider mites. There are only 2 things I can think of that are different this year than in the past. 1. Spring has been relatively dry. We've had about 5 1/2" of rain in the last 1 1/2 months, but it happened in 3 or 4 days with temps in the 70's and 80's and very sunny inbetween. So, from my perspective, this spring has been relatively dry compared to the last few years. 2. This year is the first year I planted marigolds since I moved to this house in 2006. Only after the spider mite trauma, did I come to learn that marigolds are a spider mite magnet.

The first plants I noticed infested by spider mites were 2 newly in-ground planted rose seedlings and my 2 potted roses (all of which were in the front yard). I discovered this sad situation about 3 weeks ago. I cut away all the dead, dying or yellow parts and sprayed with horticultural oil doing my best to cover both sides of every leaf and all the stems. One of the potted roses, which had the worst infestation, I just cut back a lot in order to be able to reach the most infested parts (around the base of the bush).

Anyway, a few days later I noticed that some, not all of the marigolds, had spider mite damage. They were mostly on the smaller seedlings that were in full sun areas in the front and back yard. I sprayed them with the hose, and after they dried, I sprayed on the horticultural oil.

A week later, I noticed that one of my best growing Cosmo seedlings (nearly 2 foot tall) in the front yard looked "singed" at the top. Upon closer inspection....spider mites. I treated it the same as I did the marigolds.

Ok, now going back to last season...Last spring I planted 4 small buddleia. I had never grown any before but when their leaves began yellowing along the veins and appearing dull, I was baffled. The leaves looked like they had a yellowish, powdery substance on them, yet there was no powder to be wipe off. New leaves were fine, though. After researching this issue, the only thing I ran across when researching the symptoms was powdery mildew or downy mildew. Thus, inexperienced me, removed infected leaves, and sprayed with a fungicide. I did this a few times and then cool weather came and I just cut them back.

This spring, the buddleia were growing great and and when they got to be about 2 foot tall, I began to see the yellowing, dull appearance of the leaves. So, yesterday, my impatient and frustrated self removed 2 of bushes and tossed them into the trash deciding that I'd rather have plants in that spot that I know won't give me as much of a hassle. The other 2 bushes were across the yard in a different area. I debated whether or not to pull them out too as they are uniformly showing the yellowing, dull signs. I decided to leave them and see if I could find a solution to their problem. For some unknown reason, I looked under one of the worst infected leaves and lo and behold....spider mites! Yep, every dang leaf had them! I was happy to have finally discovered the reason these bushes had the yellowing leaves for the last year, yet ticked that they were so infested. The damage by spider mites on the buddleia didn't look like the mottled leaf damage on my other ornamental, which is why the infestation got so bad, and why I never put two and two together before.

Ahhh...then last evening, I noticed my best growing, and most beautiful Queen Victoria Cardinal Flower had a dead section. When I went to remove it, thinking it died because of the warm weather, and fearing I must not have watered it enough, I see the dreaded webbing at the top and down in the crown at the bottom. *cries* I race for the horticultural oil and sprayed the living daylights out of it and the 3 ajacent cardinal flowers- I had found webbing at the top of another one.

So, now I am here seeking advice from you all. I know all the advice about "How to get rid of spider mites" says to be sure and get the underside of all the leaves. Here are my questions...

1) What do you do when there are hundreds of leaves and tons of tiny leaves at the base of the plant like on my Buddleia? Or tons of leaves on the basal rosettes of Cardinal Flower? There is no way to spray each individual leaf, so how do I manage to reach all the spider mites? I know spider mites don't like being blasted with water, so should I just blast those hard to get areas with water a few times?

2) When spider mites are blasted off the leaves, do they die or just land wherever, and go find another plant?

3) When I spray horticultural oil on plants infested with spider mites, should I also spray the ground with it? The direction didn't say to do so, but from what I've read, spider mites crawl onto the plant from the ground area around the base of a plant. Shouldn't that area be treated as well?

4) Should I cut back my remaining 2 Buddleia, tossing the discarded branches into the trash, so I have less to treat & to have a better chance to reach more mites? Or should I just toss both plants in the trash?

5) My potted Colocasia Black Beauty has had spider mites a few times this spring. Yet, my Colocasia planted in the ground haven't gotten any mites so far. The one in the pot get watered 1-2 times a day, as do the ones in the ground, unless it is cloudy, then it is just once a day. I know the soil is moist, so I am not sure why the mites prefer the Colocasia in the pot over those in the ground. Could it be because the one in the pot receives the warm/hot afternoon sun and the ones in the ground are in more shadier locations with morning sun & late afternoon sun only? When I water the potted one, should I also mist the back of the leaves once or twice a day to help keep the mites at bay?

6) What miticide is best to help with this infestation and kill the eggs as well as the living mites? I have a feeling this is going to be the only way to curb these annoying pests.

Any help would be appreciated!

Thanks!

Give this site a look....some very interesting info

http://www.ext.colostate.edu/pubs/insect/05507.html

Red Spider mights are a nightmare for every plant person as you have discovered, it is not the easiest bug to find unto it has reached epidemic proportions and the soft fine webs have almost smothered the plants especially at the growing tips for some reason.

I was advised to mist my plants, mine were growing in pots inside, anyway it is important to mist the underside of the leaves as well as the stems, flowers etc, this misting will not kill the mites but they stop breading when in damper conditions. I also tried soaps dissolved in water, tried oils the same way as the soap and misted this onto plants too but, it helped for a bit but, nothing got rid of it, and at each attempt, between treatments, the mites just increased.

I was then advised to try a predatory was that with the naked eye, you cant see it, as also like the red spider mites, so I sent away for this wasp, believe me, it did the trick, within 2 weeks I noticed tender new growing tips growing, I had several different types of plants affected, Angels Trumpet, Dipladenia, Mandivilla and other plants we have to grow inside,
The predatory wasp is called Phytoseiulus,it requires a minimum temp of 10C / 50F, I don't know IF this is available in USA but the company I used to get this has a web site, www.defenders.co.uk have a look at the site and IF you require any further info, they are very helpful and you can reach them for advice.
Hope this can help you out a bit.
Good luck Hope you can find a cure soon. WeeNel.

Without pests, beneficials will never show up. Just relax and let nature handle it.

Never a truer word spoken purpleinopp, we all fret soon as we see something to fret about, but it's hard to sit and watch all your hard work or effort go hey-wire and cant find anything to prevent the certain death of a plant, for myself, it's not always the plant that I am trying to fix but, the cost of a load of plants that within a few weeks can be fit only for a garbage, all down to a tiny little mite that appears and is the cause of a lot of worry for most gardeners, I would hate to know there was a way of saving the plants infected and not find some way of helping to save them and prevent those little horrors from moving onto another plant or even a neighbour.
The worse culprit for me is the infestation of spider mites coming from garden store plants. When I buy for my greenhouse or conservatory, I keep them away from these plants for ages and then add them when think it is safe, all of a sudden webs appear and plants droop with leaf fall and yellow leaves, OH the joys Eh. I'd rather try save a plant after it has tried it'self to to grow against all the odd's so for me, nature is sometimes too late in coming to my aid, but I do agree we need to remember there are always beneficial insects that can help us out but unfortunately we cant give those a personal invite when a problem occurs so relaxing aint always a cure for me.
Hope this helps give the other side of the problem some have to cope with.
Best regards. WeeNel.

SM are a terrible problem here Ive lost many plants to them, they thrive in hot dry areas, and are attracted to some plants more then others. They really like Butterfly Bushes. They have killed more then one. I waited for nature to take it's course and now the plats are dead. I've had trouble with them in my veggie garden also. They attach beans, cukes and tomato plants readily.

Before the webbing comes the signs are so vague that it's hard to tell what the problem is. One of the treatments is spraying with water because the mites don't thrive in that environment. Neem ( organic ) is also a good mitecide but don't use it during the heat of the day or when the sun is out. It's also an insecticide so it will kill beneficials so don't use when bees are active. If your not concerned about organic and just want them dead use Othro Home Defense Max it has Bifenthrin, for mites.

Thank you all so much for your input!

WeeNel, I, too, find it hard to spend so much money, time and effort on plants only to sit back & let spider mites kill them. I buy many bags of organic planting soil & Black Kow compost, and mulch annually. I also buy various types of liquid & slow release fertilizers for the many different types of plants I have throughout my yard. I spend countless hours planting, pruning, deadheading, mulching, and watering throughout the year, and some I have to do daily. Then add in the time, energy, and money I spend on the plants I overwinter & plant back out in spring. Then there are the plants I grew from seeds under lights for months & planted outside in spring. It is REALLY hard to do nothing when I see them being attacked by spider mites. It is even harder when I have already spent a lot of time fighting/preventing plant disease, moles, aphids, caterpillars, slugs and snails!

Already this year I have pulled up and thrown out 2 Buddleia due to spider mites and completely pruned back a potted mini rose to just the stems due to spider mites. The spider mite infestation on the potted rose was horrible and I wasn't able to get to the lower leaves and stems at the base because it was so dense and there were a lot of thorns! I didn't know what else to do, so I cut it back completely & moved it to the back corner of the yard in part sun. I am confident it will rebound at some point.

Then yesterday, I spent a few hours removing the ugly leaves from the remaining 2 Buddleia (thank goodness they are dwarf versions) caused by spider mites. I did remove A LOT of leaves but it was necessary in order to reach the leaves and stems at the bottom. I debated many times during the leaf removal whether I should just toss them in the trash, too. However, I decided I would give them one more try and work really hard to keep the mites off of them.

As for the ladybugs....all of my life, prior to beginning gardening, I loved ladybugs! Now that I know they feast on aphids and spider mites, I want to cry if I see a ladybug on my plants. LOL Seriously, I saw a ladybug on a leaf on my potted Hibiscus yesterday and at first was like, "Awww, a ladybug!" Then panic set in and I was like, "Crap....does it have aphids or spider mites?" I quickly began the inspection! Thankfully, I saw no webbing, mites or aphids. But I know it doesn't mean they weren't there. The skeptic in me figures I just missed them because their infestation isn't so bad yet.

themoonhowl, thanks for the link. I will check it out !

1lisac, since I am a beginning gardener, I have tried to adhere to the "don't get the foliage wet" gardening guideline I have been told and read about many times over the last few years. I've only watered at the base of plants. However, since the infestation of spider mites this year, I have changed my mind. Every plant is gonna be getting a good weekly blast of H2O from me. Of course, I will only do it early in the morning :) Honestly, I'd rather battle leaf spot or powdery mildew than spider mites!

Again, thanks so much for the responses.

I have a small 25 gallon plastic drum that I call the dunking drum. I have been know to fill it with warm water and add dish soap, dig up a plant, suspend it in the drum upside down with a bag over the roots and let it sit submerged for 1/2 an hour to get rid of spider mites....I figured one day since I was gonna get rid of the plant I might as well try something drastic......it worked...lots of dead spider mites in the drum and none on the plant.

That is a good idea, moon. But what do you do when the plant is rather large? Do you cut some of it back before digging it up and dunking it? Does it kill the eggs or wash them off, or do you have to retreat the plant 7-10 days later?

By the way, I just got finished reading the link you sent me. Very informative! Thank you!

If the problem has gotten so bad that I am gonna lose the plant, I whack it back and dig it up....rinse a good bit of the soil off and bag the roots just as protection. Then I sort of "churn" the plant in the water, let it sit and churn it again. I rinse it well with the hose and then search for critters.Since the underside is well exposed, I follow up with a miticide and then stick the root ball in a container with some soil and keep it out of direct sun for a few days. That way I can inspect for new mites. I take a sheet of white paper and hold it under leaves and shake the branch...if no mites fall on the paper, I use a white paper towel and gently wipe the underside of some of the leaves. If the paper is clean, I check it again in 7 to 10 days. This is a last ditch effort for a plant that would otherwise be destroyed. It seems to remove both adults and eggs.

Glad you found the link useful.

Moon