Spider Mites

The most likely cause of damage that looks like this on many plants is spider mites. They are sucking insects and cause this white mottled stippling on foliage when a plant is typically stressed. They are very hard to see, but the underside of infested foliage often looks dusty, sticky, and vaguely web-like and dirty. You can read more about spider mites and how to control them here: http://bit.ly/1pJ46WX You can also go to your local garden center for confirmation of its identity and ask for an organic or other recommended control for spider mites that is appropriate for your plant and then use the product according to directions. Do not use an insecticide as this would not be effective. You will need a product formulated with a miticide if it is mites.

The most likely cause of damage that looks like this on many plants is spider mites. They are sucking insects and cause this white mottled stippling on foliage when a plant is typically stressed. These critters aren't really spiders although they are related to them. They are very hard to see, but the underside of infested foliage often looks dusty, sticky, and vaguely web-like and dirty. You can read more about spider mites and how to control them here: http://bit.ly/1pJ46WX You can also go to your local garden center and ask for an organic control for spider mites and then use the product according to directions but at thi point in the season, just compost it. No point in wasting money. Marigolds should be grown outside not indoors.

This appears to be the damage done by spider mites, a common problem. Symptoms of injury include flecking, discoloration (bronzing) and scorching of leaves. Injury can lead to leaf color loss and even plant death. Natural enemies include small lady beetles, predatory mites, minute pirate bugs, big-eyed bugs and predatory thrips, but of course that's only outside. One reason that spider mites become a problem is insecticides that kill their natural predators. Another is low humidity, such as indoors in winter.
Spider mites are barely visible to the naked eye, and are difficult to control. Insecticidal soap can help, especially if the problem is caught early and the leaves, both sides, are sprayed well. Or look for another product with "spider mites" listed on the label.

This looks like spider mite damage, though that seems usual for rosemary. Do you see any evidence of other insects like aphids? Look for the fine webbing and small spider like mites on the leaves. The mites themselves are very difficult to see with the human eye, so hold a piece of paper below the leaf and tap or shake slightly to see if anything falls off, or, take a spray bottle of water and spray it in the leaf axils. A magnifying glass can also help. While the mites are very difficult to see, their webs catch the water and becomes more easily visible. You may wish to show your photo to a local garden center for confirmation of the problem, so they can help you select the right control. Horticultural oils and neem oil are natural controls for mites.

Spider Mites are tiny and you almost need a good hand lens to see them. There is no sticky residue. They spin very fine webs which catch their frass and dust and perhaps bits of dirt. They have a 5 day reproductive cycle and reproduce year round indoors. Check other plants in the area as they can float about on a good draft to new site.

Take the plant outside or to a bathtub and use Insecticidal soap, paying especial attention to the undersides and base. Wait 20 minutes and rise well. Repeat at 4 day intervals until all seem to be gone. Continue to monitor plant at weekly intervals for a while. To prevent dirt washing from the pot, tape the top closed around the stem. Duct tape works pretty well, or you can cut a piece of rigid plastic to fit around the stem and over the soil.

This looks like spider mite damage. Do you see any evidence of other insects like aphids? Look for the fine webbing and small spider like mites on the leaves. The mites themselves are very difficult to see with the human eye, so hold a piece of paper below the leaf and tap or shake slightly to see if anything falls off, or, take a spray bottle of water and spray it in the leaf axils. A magnifying glass can also help. While the mites are very difficult to see, their webs catch the water and becomes more easily visible. You may wish to show your photo to a local garden center for confirmation of the problem, so they can help you select the right control. Horticultural oils and neem oil are natural controls for mites.

Don't worry about the cut stems. They will dry up. The webbing on your plant could be spider mites. We've included a link so you can see what these little sap sucking spider-like organisms look like, but at this stage of damage, you may want to remove the affected leaves and treat with an appropriate pesticidal product as recommended below, or in the web link provided. For future reference, if you catch the problem before it gets too bad, you can control them by spraying with neem oil or pesticidal soap, which can be purchased at most garden centers. Be careful to read the labels and apply any of these types of products properly. Be careful to spray the undersides of the leaves, the stems, and the tops of the leaves. Repeat the application as recommended on the product label to kill any new mites that hatch from eggs afer the first application.
http://www.ipm.ucdavis.edu/QT/spidermitescard.html

The most likely cause of damage that looks like this on many plants is spider mites. They are sucking insects and cause white mottled stippling on the top of the foliage when a plant is typically stressed. These critters aren't really spiders although they are related to them. They are very hard to see, but the underside of infested foliage often looks dusty, sticky, and vaguely web-like and dirty. You can read more about spider mites and how to control them here: http://bit.ly/1pJ46WX You can also go to your local garden center and ask for an organic or other recommended control for spider mites that is appropriate for your plant and then use the product according to directions. If you don't see the stippling on the tops of the leaves, it is possible it is just normal coloring, but spider mites are very common on houseplants that have been subjected to the dry indoor air of a northern winter.

This is being caused by a spider mites. These tiny spiders (can only be seen with a magnifying lens) suck plant sap and chlorophyll from the leaves, causing the speckled appearance we see on these leaves. You may also see some very fine, disorganized, webbing with mites in the web. If you confirm, you can use insecticidal soaps or horticulture oils to control them, but don't over-use these products because you'll probably be killing other beneficial mites that are natural enemies of these mite pests. When many of the predatory/natural enemies are killed, the spider mite pest population can sky rocket and get worse. You can also help keep the population of pest mites down by occasionally washing off the leaves of the affected plants early in the morning (and allowing them to dry throughout the day). Here are a couple of web-links with more info:
http://www.ipm.ucdavis.edu/QT/spidermitescard.html
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7405.html