help - My new greenhouse has spidermites/ white flys

Leave the newest leaves-or any leaves that don't have any spider mites on them=but as infected as those leaves were that you showed us, I am thinking that it will be all but the newest leaves. Plants can produce new leaves from just a root system-they do it all the time,-trees in the spring, plants coming out of dormancy etc. As I said before, I think that the columbine is going to drop all its leaves anyway as i think it will be going into dormancy-it does here when planted in the ground.

You mention a Bayer product for killing grubs in the ground. I said don't use that one, use the one that SB mentioned-Bayer Advanced Tree and Shrub.


Yes-as soon as the sun is not on the grhouse anymore would be a good time to spray-the best time. Are you planning on spraying something now?

I am very thankful for all of your help, thank you !
I am standing by
trying to figure what to do next

I have a 4 foot Brugmansia in the greenhouse which is bloombing and has a smattering of whiteflies. A couple of bananas which are also looking fairly good

It appears that I should remove more infected leaves and probably all of the Columbine growth because it all looks like the photos. I removed all of the plant to the ground on the worst of them 3 weeks ago and they now have about 1 inch of new healthy light green growth, no sign of insects !

because there are also a few adult white flies I feel that I should spray to prevent them from multiplying ?

The neem based product does not seem effective on plants as infected as my columbine

so I tend to feel that I have sprayed once (The malathion)
5 days ago

looking at the 3-4 day rate at which the whiteflies reproduce it seems to me time to hit the next group as they hatch.

you mention dormancy, do your deciduous plants drop their leaves in the Greenhouse during the winter ? what triggers dormancy ?

my green house is heated and I don't expect it to get below 50 in the GH this winter
our average low is in the 50s dropping to the 40s in december
our first frost is months away (Jan - Feb)

There is a line in deciding whether to spray an infested leave or to remove the infested leaf as it is too damaged to ever come back. Your columbine has crossed that line. That is why the Neem did not seem to work-nothing would have made those leaves reverse course and get healthy. It sounds like you knew it with one of them and removed the leaves and saw new, healthy growth-so why not do the same with the others? Less spraying and more preventative actions, like removing leaves as soon as you see the problem is the key here!

It is not every 3-4 days that the larvae hatch, and this is important to know/get right. It is every 5 days, so you can spray every 5-7 days over a period of at least 3-4 wks and you will get them all.

I don't know what you mean " so I feel that I have sprayed once (malathion)." Are you thinking that because the leaves were so far gone that that means that you didn't spray the Neem?

Dormancy is a whole other topic-in that it affects different plants in different ways in different zones. For you, even though you are in zone 9a, and in a heated grhouse, it is still winter-the strength of the sun is less and the position of the sun is different and less hrs of sun thru the day. Also the temps are cooler during the day/night. All of the above trigger dormancy.

Put a systemic in the soil-the Bayer Advanced Tree and Shrub. Follow SB's directions, you saturate the soil with the solution. Also look for the eggs on the bottom leaves of the plants that the whiteflies are attracted to.

sorry to say I wasn't that experienced to take off damaged leaves
they were dead and dry !

have you tried to prevent dormancy by adding lights ?
does it damage a plant to try to convince it there are no seasons ?

I discussions of bananas producing mature fruit in more than 12 months, do they just stop growing or do they drop their leaves when they are protected from frost, freeze and cold weather ?

Jim,

Your newer pics confirm a heavy infestation of spider mites. I completely agree with TL, removal of dead/dying foliage is important, and for several reasons...it obviously continues to harbor pests, but also it is useless shade, and finally it impairs the delivery of your pesticidal sprays to the parts of the plant that are still viable. Get rid of the nasty foliage and put it in the garbage, not the compost pile.

The Bayer product you have is not the imidacloprid I use. It sounds as if it is granular, not liquid. Neither is "approved" for this type of application. My recommendation is based on personal experience and the experience of many others who have used it in a similar fashion, 2T/gallon, watering in well. You won't find this application rate on the label. Although I have seen it on the shelves, I have no experience with the granular product, and cannot recall hearing of any other gardeners who have used it. Brugs are prone to whiteflies and would be good candidates for such a systemic treatment.

I will reiterate my recommendation to use a series of alternate sprays...pick your poison...I like permethrin, pyrethrum, and neem, they are relatively nontoxic and can be used on edibles generally within a couple of days of harvest (don't quote me on that, I don't have the label in front of me)...but I also have used carbaryl and acephate...you could use malathion, abametin, acephate, cyfluthrin, whatever...choose 3 or 4 of them, get a good 1 gallon sprayer and a mask if you like, bend the sprayer tip at a sharp angle to aid in getting underneath the leaves, and hammer them when it is cool and they are immobile. Cover every leaf surface. Your are after control, don't expect eradication, at least for this winter I think that would be unrealisitic.

This is probably a stupid question, but why to you need columbines inside a GH in zone 9? I have about 180 different varieties of plants in my GH and if I find a plant that is bug-prone, I unceremoniously remove it. I have to wonder why you just can't move those columbines outside.

Yellow sticky traps are only useful for monitoring whitefly populations and alerting you to an increase in their numbers. Don't rely on them for control.

Dormancy...really a new thread entirely...leaf loss depends on the plant...some slow growth and don't lose many leaves, others partially defoliate, others completely. In a zone 9 GH with min temp of 50, I would not expect many plants to completely defoliate. Generally speaking, I would say that you don't want to fight dormancy with lights, except for things like veggies, tomatoes, that sort of thing. Many plants are programmed for a little rest, whether it is characterized by shorter days, less light, less water, or whatever. I have killed plants which appreciate a dormant period by trying to force the growth along through the winter.

SB

your question - why to you need columbines inside a GH in zone 9?
my reason -- The plants in my greenhouse are expendable, plants to learn with !

I grew most of the plants in the house under lights from seed in the early summer, before I purchased the greenhouse, in an effort to have some nice plants to set out in the garden after our killer summer was over. All of the plants that I have grown from seed have been small not like those at the nursery. So I am trying to figure out how to produce the nursery or better quality seedling

We have two major gardening seasons here in the sacramento valley, each a few months long. The summer is a killer for about 30 days (above 100 degrees) that sun will kill most any normal flower plant (everything goes dormant) and encourages us to grow everything in the shade! We don't want any lants in the afternnon sun! The winter consists of two or three nights below freezing with daily highs above 50 degrees and nights above 40 degrees

tropicals grow here, some need protection from frost but we have so little frost it is not a major problem

your coment -- if I find a plant that is bug-prone, I unceremoniously remove it.

I agree with you and go even further. If it does not grow into a beautiful plant I don't want it in my yard or greenhouse !

But in my current level of experience, my doubt is that "it is not the plant" it is "my lack of skill and experience"

Stressbaby's statement - The Bayer product you have is not the imidacloprid I use. It sounds as if it is granular, not liquid. Neither is "approved" for this type of application.

see below that there are severla bayer products with similar names
the ones below all have Imidacloprid
Complete Insect Killer for Soil & Turf Concentrate I HAVE THIS ONE IT is a LIQUID

which one are you using ????

What's inside the package?Bayer Advanced™ products for the lawn, garden and home contain highly effective active ingredients recognized worldwide for their results. Many of these active ingredients, or the components in each product that kill the pest or fungus, are not available in any other consumer retail brand.
http://lowes.bayeradvanced.com/garden/master-gardener/active-ingredients.cfm

Imidacloprid (MERIT®)
Curative & Preventive
Season-Long Grub Control Granules
Season-Long Grub Control Ready-to-Spray
Tree and Shrub Insect Control Concentrate
All-in-One Potting Mix
All-in-One Potting Mix for Roses & Flowers

Imidacloprid (MERIT®) + beta-cyfluthrin (TEMPO® Ultra)
Curative & Preventive
Complete Insect Killer for Soil & Turf Granules
Complete Insect Killer for Soil & Turf Concentrate I HAVE THIS ONE
Complete Insect Killer for Soil & Turf Ready-to-Spray
Rose & Flower Insect Killer Ready-to-Use Spray
Rose & Flower Insect Killer Ready-to-Spray