Here are some questions and answers about pests from Emily's mailbox.
Iguana
Poison plant questions
Q: I was wondering will snake plants harm my iguana if he eats it ?
A: (The readers will think we make this stuff up!) We do get a lot of poison plant questions.
Here are our favorite websites for poison plants:
http://www.ansci.cornell.edu/plants/index.html http://www.vth.colostate.edu/poisonous_plants/report/search.cfm
As for the iguana, I'm afraid you will have to go to www.EmiliGuana.com (alright, I made that up).
Black Medic
Q: I have a weed in my garden that resembles a small clover plant and it bears small yellow flowers. Could you please tell me how to rid my garden of this pest? I think it is called Black Medic, but I am not sure.
A: Right on! You have accurately described Black Medic which is Medicago lupulina.
The "Southern Living Garden Problem Solver" says to hand pull the young plants before they go to seed. Older plants have a tough taproot that is hard to get out.
Thick mulch will prevent the seeds from developing.
In the spring, before planting (if that is the type of bed that you have) try soil solarization. Covering the bed with thick plastic for 4-8 weeks to kill the seeds with heat.
Failing all of that, the Southern Living book says to control or kill it with a herbicide (like Weed B Gone) on lawns or a herbicidal soap in gardens or (heaven forbid) Roundup. All of which can be purchased at your garden shop. Read the label. Be careful.
Thrips
Q: I live in the northeast and both myself and my Uncle have the same problem with our gladioli. They seem blighted and some have white lines especially the dark colored ones and the buds are not opening. Do you think this could be from under watering or over watering. Could it be related to all the rain we had late spring and early summer?
Any information and or tips will be greatly appreciated.
A: You probably have thrips.
Thrips have bodies that are brown, yellow, or black and shaped like a grain of rice. However, they are only 1/20 th of an inch long so you probably cannot see them.
On gladiolus, the leaves are mottled with brown spots and a silvery white streaking and look stunted. Many flower buds dry and fail to open.
Thrips are a common gladiolus problem. They attack during warm, dry, spring weather, usually.
You can control thrips by either spraying an insecticide or use a systemic insecticide. You will have to look in your garden shop and read the labels to see what is sold in your area.
Crown Rot
Q: My snake plant has crown rot. Any suggestions?
A: Crown rot is caused by soil-dwelling fungi and bacteria.
Every resource I can find says the same thing: "There is no cure for this disease. Immediately remove and destroy any infected plants and the soil around them." That means all the soil in the pot and wash all the soil out of the pot before using it again.
Squash bugs
Q: Does the soap sprays or the "bug juice" control squash bugs? I would like your advice, or your directing me to a source for advice, on controlling these guys.
A: Squash bugs (anasa tristis), or stinkbugs love plant juices and squash.
"Rodale's Landscape Problems Solver" says that frogs will control the squash bugs. However, what if you have no frogs?
The "Southern Living Garden Problem Solver" says to pick the undersides of transplanted or newly sprouted squash plant for egg masses and pick off affected leaves and destroy them. Also, "you can kill nymphs and adults by spraying the undersides of leaves with insecticidal soap."
Good luck.
Spider Mites
Q: Do you have any Organic tips for destroying Spider Mites. I have a Poinsettia that I have had for five years that was ravaged by them this year so I had to drastically cut it back which hurt. It may still have some because it is slow to re-leaf.
A: According to Rodale's "Landscape Problem Solver" there are at least two organic solutions to spider mites:
Big eyed Bugs prey on spider mites and is found in western North America.
I also found two Big eyed bug references in Florida: http://creatures.ifas.ufl.edu/beneficial/bigeyed_bugs.htm
and: http://www.nysaes.cornell.edu/ent/biocontrol/predators/geocoris.html
Also Green Lacewings (Chrysopa carnea) are probably the best beneficial insets that you can buy through the mail. See http://www.kunafin.com/lacewings.htm and http://www.gdnctr.com/ipm.htm
Q: I think I have spider mites sucking sap from the plants. How can I get rid of them?
A: Spider mites show up when the plant is very dry. Wash leaves with soap and water. Continue several times. A product known as insecticidal soap will also do.
Caterpillars
Q: I have this smooth green caterpillar eating the leaves of my angel trumpet. Do you know what the name is and most important how do I kill it?
A: You want us tell you how to kill something that is going to turn into a beautiful moth or butterfly?
Ok, so maybe you do not like them eating leaves.
According to Rodale's "the methods for controlling caterpillars are basically the same for all species:
"Handpicking.
BT (Bacillus thuringiensis) kills most leaf-eating caterpillars. Dust all parts of the leaves, especially the undersides, reapplying the dust after it rains. You can also make a foliage spray of Bt and apply it to infested plants every 10 to 14 days until the caterpillars are gone.
If the infestation is out of control, spray all sides of the leaves with pyrethrum. Usually, two applications, three to four days apart, will solve the problem."
Alligator weed
Q: How do you get rid of alligator weed without using powerful chemicals (e.g.., Roundup)? Did you have any success with biological methods?
It has invaded my vegetable garden the last 2 years (I think I picked it up through bags of leaves people left on curbs) and it is spreading, particularly in wet areas. I have spent a lot of time digging and hand pulling but I can never get the entire root and it comes back. It likes the hot summer climate here, and I don't have the patience (or stamina) to pull it out during the summer!
I appreciate any ideas you have,
A: Since we do not use herbicides or any chemicals, alligator weeds are a constant battle.
Not so much where we have lived before (above zone 7) but here in NorthEast Florida (zones 8/9) it seems to love the hot, dry, wet, humid weather and it flourishes.
I am constantly pulling it. Constantly.
Grubs
Q: I have a garden and had one grub last year know I have seen seven this year and killed them. But I don't want the situation to get any worse, so do you have a solution that I could do for this. I would appreciate it very much.
A: Three natural controls for Japanese beetles are: Milky spore (Bacillus popilliae) - it will destroy the grub stage. Also, beneficial nematodes such as (Heterorhabditis) The third is neem oil. It comes form the Neem tree (India). When put to the soil it kills the grubs and when used on ornamentals it kills the adult beetles.
(This from the Southern Living Garden Problem Solver). This book also recommends insecticides, which I hate to use.
Q: I would like to know if anyone has used "beneficial nematodes" to kill grubs. I'm trying to control the Japanese beetle.
A: According to Rodale's "Landscape Problem Solver" under their section on controlling Japanese Beetles: "if grubs are a particular problem in your garden, you should consider applying beneficial nematodes to the soil. They will seek out the grubs, burrow into them and reproduce. Nematodes release bacteria which kill the grubs."
Southern Living "Garden Problem Solver" for white grubs: "add beneficial nematodes to the lawn. Adding the biological control called Milky Spore (Bacillus popilliae - Dutky) to the lawn will kill Japanese beetle grubs.
Sooty Mold
Q: I have a 4ft tall gardenia plant in my front yard that will not produce any blooms. I saw a lot of black stuff on the leaves all the way down the stem. I was told that I could wash the black stuff off with some mild detergent so I did and the mess would not come off, so I carefully washed each leaf with my hands.
I think I need to pull it up trash it and replant another one. If I do is there something I need to do to the soil so as not to get the black stuff on the plant again, or can this one be salvaged?
A: From the "Southern Living Garden Problem Solver" book (for Gardenia):
"Sooty mold. A black powdery substance covering the tops of the leaves.
Solution: Sooty mold lives on honeydew secreted by sucking insects, such as aphids, scales, mealy bugs, and whiteflies. The mold can prevent sunlight from reaching the leaves, thereby reducing plant vigor. Eliminate honeydew by controlling the insects with insecticidal soap, horticultural oil, or acephate (Orthene)"
Sounds like you have already tried the soap. Perhaps the oil. I think you are on the right track.
Rabbits
Q: I planted ornamental grass around a tree and the rabbits are eating it to the ground. What can I do to keep the rabbits out?
Allen, TX
A: First thought is to move. Okay, that only gets you away from those particular rabbits.
We sprinkle ground up hot pepper on and around the plants (used to raise Thai, cayenne, jalapeno and had a lot left over at the end of the salsa season.) Dry the peppers then grind them up in a blender. That only works until the next rain, but can be effective short term.
Here is what the experts say:
Southern Living "Garden Problem Solver"
"...rabbits cannot climb. A chicken wire fence, 3 feet high, around the vegetable garden sends these furry pests over to your neighbor's plot. Just make sure you anchor the fence 6 inches deep in the ground, because rabbits can dig." Not a very good solution for your grass.
Rodale's "Landscape Problem Solver"
They suggest traps (10"x12"x30"box trap) "bait with fresh greens, carrots, or fresh clover." Of course, you knew that.
They also suggest a dog or cat in the yard. This, of course, might compound your problems.
They also say, "Many gardeners find that used cat litter repels rabbits when it's sprinkled on the lawn and around ornamentals" "Replace after each rain." "Do not use cat litter around edible plants" This would solve a disposal problem for your neighbor, if they have cats.
They also talk about repellents. "Taste repellents are more effective (for rabbits) than scent repellents.
Scent repellents: anything that smells of blood. "sprinkling dried blood meal on the soil around vulnerable plants...reapply after each rain."
"Some gardeners report that vinegar wards off rabbits. Save a few corn cobs after a meal and cut the cobs in half. Soak them in vinegar for 5 minutes, then scatter them throughout the flower or vegetable garden. Two weeks later soak them again in the same vinegar. Your can keep reusing this vinegar; just keep it in its own labeled bottle."
"Other rabbit repellents reported effective by some homeowners include lion and tiger manure (sold by some zoos as ZooDoo); a solution of cow manure and water applied as a spay; onions interplanted among the crops; fish tankage and bone meal; and soybeans planted adjacent to the garden."
Taste repellents:Purchase a commercial taste repellent. They again recommend dried blood, hot pepper or black pepper.
Wait a minute! Why am I telling you all this. You're in Texas. Don't you have a gun?
Good luck.
Mistletoe
Q: Is there anything you can do when a tree starts growing mistletoe. I live in Texas.
A: Yes the best early prevention of an invasive parasite is to cut the limb... as close to the mistletoe as possible.
This may seem harsh but it is what is recommended.
Q: Can mistletoe be cut from the host tree and planted in a pot to make a topiary?
A: I wish I had thought of something like this. However, in all my research on mistletoe (Philodendron, various species) I can only find two general areas of comment:
How to get rid of it and How poisonous it is (for instance, if you bring it inside).
Since it is a parasite, growing on woody plants, I doubt that it will grow in dirt. They take nutrients and moisture from the host plant. It propagates by seed. The seed has to land on another branch in order to germinate.
So my guess is, I don't think so.
Wild Radish
Q: How can I eradicate Wild Radish?
A: I suspect you will have to use a selective herbicide. Be very careful when you do. Read the directions very well. You could also do manual digging.
The root is your problem it is probably well established.
Try to let the plant not go to seed. One year of seeding equals seven years of weeding.
Good luck
Fungus
Q: I live in The Boston area. Every year I have fungus (red thread, I believe) that destroys approximately 30/40% of my grass plants. Every year at Labor Day I aerate the lawn, put plenty of the slow release palletized lime down, re-seed and fertilize with step 3 of Scotts 4 step lawn fertilizer program.
I am writing you to find out what I can/should be doing to try to eliminate the fungus. I of course have contacted Scotts Lawn Care Products and they recommend I use their fungus control product. I have in the past, and it does work to some degree, however, it works more as an inhibitor than a preventer.
Can you tell me what I should be doing or where I might go on the Internet to get some answers to this chronic problem?
A: Fungus grows because there is too much organic material around, sometimes wetness or dampness, darkness, and depending if the host is air borne or not it may becoming form some direction.
Yes a fungicide should do the job. Probably more than one application.
Thatching and aerating may be spreading it.
I would not put lime down unless your soil testing indicates needing it. I think your local count horticultural agent should be able to help there .
Personally, I am not a grass-lawn person since it is murderous in zone 8b where I live. I remember lush, green, fescue lawns where one could romp and play with no problems whatsoever in the north. Here we fight fire ants on a daily basis.
As far as finding good sources on the Internet, your land grant University in your state should have a site. The University of Massachusetts site is www.umass.edu/umext.
White Fly
Q: I have a big white fly problem. I've tried various sprays, they cut the numbers down but don't eliminate them. I looked on your site; I didn't see any white fly solutions. Any ideas?
A: White fly can be controlled by using soap and oil spray. Or a neem spray.
Predators of the white fly are lacewings, big-eyed bugs, and lady beetles.
Try using an insecticidal soap. Or making your own, using dish detergent soap and water. Several applications may have to be used.
Q: I live in Rock Hill SC. and have four light pink Crepe Myrtles. Each summer they get white fly and when we spray them, they look terrible. (Sticky, mildew, yellow leaves.) They seem very attracted to my trees.
Is it possible they get too much water or is it the mulch? I never had this problem in Texas. What can I do!
A: I don't think it is either the watering or the mulch.
We have gardener friends who just throw up their hands and give up on white flies, but we try to jump right on them when we see them.
We constantly look for small white fly infestations and begin spraying daily or every other day with insecticidal soap. If you don't stay ahead of them, they take over. However, if you do stay ahead of them, you can beat them. We rarely spray for more than ten days. Keep checking and may have to spray once more a few weeks later.
Dandelions
Q: I started using organic fertilizers on my lawn and I now have a lawn full of dandelions. Do you know any organic way of getting rid of the dandelions?
A: The most organic way of getting rid of dandelions is to pull them. It is a lot of work but I did it on my yard 10 years ago. You might spray with vinegar individually and see how that works.
Q: Bunches of these dandelions are attacking the wild daffodils, they won't stop & they don't just come droves, they come in groups, not droves, groups! What the heck do I need to do to destroy them for good?
A: We usually let overlapping plants fight it out. Whichever wins, we plant more of it. We get lot stronger plants that way.
Ok, that may not be that helpful.
Dandelion (Taraxacum officinale) probably arrived in the US in colonial times for its edible greens (if collected early in the spring they are not so bitter) and for its flowers which were used to make dandelion wine. Since then, we have progressed to white zinfandel. The dandelion is a perennial that reproduces by seed and from pieces of taproot.
The best method to get rid of them is to pick them in the spring before they generate much of a tap root. If you leave even a small part of the taproot, it will come back.
According to the "Southern Living Garden Problem Solver", you should maintain a year round mulch to prevent the seeds from germinating. They suggest, for chemical control, "a selective post emergence herbicide like Weed-B-Gone or Weed-Stop." Of course, be careful with herbicides around the dafs.
Photinia's
Q: I have 4 large red tip photinia's and the leaves have begun to yellow around the edges. What could the problem be?
A: Yellowing around the tips of plants can be a sign of several things. First I would suspect over watering and then it is hard to believe but under watering may also be the clue. You will know yourself, which it could be.
If there is insect infestation look under the leaves and spray with a water and soap solution..
There may also be a lack of a particular nutrient.
Since we still can stand another fertilizing application, and if the temperatures are NOT too high, I would give it some 10-10-10- and water in well or a spot of a water soluble fertilizer and see what happens.
Mulch well and keep you eye on the plant.
Photinias are susceptible to fungus and this might be the problem. Make sure you have good circulation around the plants.
It is very difficult without an on site investigation.
Dogs
Q: My wife and I recently added a golden retriever puppy to our home in Palo Alto, CA, and our backyard is inhabited with foxtails, which we understand from our veterinarian to be very dangerous (and potentially lethal) to pets. We would like to treat our lawn with a nontoxic herbicide that will eliminate the foxtails but not risk harm to our puppy. Do you know of any treatments or herbicides that you might recommend for us?
A: Herbicides indeed are very dangerous for pets.
Three of my favorite non-herbicide and organic ways to get rid of foxtail is by manually pulling the designated plant material. I know this sounds like the last resort but actually is the first for me. Good gloves, long pants and a shovel to help loosen the root. Secondly you can pour boiling water and this will kill the plant material. it will also kill the grassy areas along with attempting to hit the foxtail. The third is to pour vinegar around the plant.
The thing is, while you are working at getting rid of the plant material your dog can still enjoy the yard somewhat.
Cats
Q: Is there a way, other than store bought chemicals, to keep the 20 or so neighborhood cats from using my wife's flower garden as a litter box? Any advice would be appreciated.
A: Cats in the garden are quite a nuisance. There are several suggestions:
Inflated balloons (although this sounds silly), after popping a few balloons the cats will not be tempted to return.
Or, you can insert thorny brambles in the soil after a freshly dug flower bed or after weeding. This may deter cats from getting too comfortable.
A chicken wire across the bed may help.
Spraying the cats with water is probably not a lot of fun but they do not like it.
Garlic/hot pepper or some other stinky foul odor may keep them out. This semi-works for deer.
Aphids
Q: I've got aphids on my ferns. What is a reliable, organic way to get rid of them?
A: Using soap and water can diminish Aphids. A gallon of water and one TBS of dishwater soap. Or buy Safer. Just as the product suggests it is safe for all concerned: you, animals, and the plants.
I generally take the plants and use just plain water as a wash and hand rub the plant down over a sink.
If you do not control and get rid of aphids, they will start producing a black sooty sticky mess on the plants.
This may take several efforts but worth the time.
Q: I've recently discovered Emily's website and I love it.
I'd like to ask a question concerning aphids.
Due to you I found out that my Pachira aquatica is suffering of these almost microscopic bugs, and the sticky drops on the back side of the leaves are not something "normal". I washed the plant immediately, as you advised. Next day I've got some more drops...
What is the connection between aphids and drops ? Are they a secretion of the insects?
Manchester CT.
A: Yuck. yes, the sticky stuff is produced by the bugs.
I never heard of Pachira aquatica and it was not listed in the A-Z Gardening Encyclopedia but I finally found it in Botanica. Interesting.
Rodale's Landscape Problem Solver has about 60 entries in their index about aphids.
Rodale's says, "...they excrete honeydew which supports the growth of black sooty mold and attracts ants."
"...may be a symptom of too much nitrogen fertilizer, excessive pruning of trees, or extravagant use of pesticides that kill off aphid predators and parasites."
"spray vigorously with water three times, once every other day, in the early morning. If this doesn't help, use insecticidal soap every two to three days for two weeks. As a last resort, spray with pyrethrum."
Hope this helps.
Q: I have about twenty five house plants. I can't name them all but they are mostly foliage: mother in laws tongue, peace lily, dumb cane, and a ficus tree to mention a few. The ficus tree began excluding a sticky sweet substance from its leaves a few months ago and then most of the other large leafed plants began doing the same. The leaves are very shiny and sticky, but other wise everything seems normal. I have several jade plants and some other succulents that aren't affected. What could it be?????? What can I do about it? The floor and any thing under the plants eventually get sticky also.
A: I am afraid you have aphids, and the honeydew is what you are experiencing.
Use soap and water (dish detergent - a non-greaser) and wash off your houseplants and then rinse. You may have to do this several times. Also you can buy a product over the counter called Safer and this will help clean off the "sticky' and kill the aphids.
Separate your plants from those not affected.
This can be cleaned up and your plants will return to normal. Look for new growth for an indication.
Slugs
Q: Slugs are everywhere. How do I get rid of them?
A: Slugs really do damage plants, especially the leaves. Hand pick the larger ones loose in the evening. The beer bait works. Many commercial products will do the trick (for instance dicamateous soil). You may have to switch bait to keep them from getting immune.
Q: I have a new Angel's Trumpet, planted at 8" tall 8 weeks ago. It is now about 20" tall and developing a few 'trunks'. Problem is - something is eating the leaves (about a 1/4 or more of each leaf is gone). On 04 June I sprayed it with Bayer Advance Insect, Disease & Mite Control and and that seemed to stop it, but now the eating is going full bore again. I do not see the culprit. Am told it might be slugs at night.
I'd thought of wrapping the trunks with cloth and putting grease or Vaseline on the cloths (stops ants - thought this might work with other climbers or slugs). Any suggestions? Thank you, Murf
A: Our guess is slugs, although it could be anything. If you will put some beer in a tuna can (or mayonnaise jar top) and set it next to the plant in the evening, in the morning the dead slugs will be floating in it and you can tell if you have slugs that way.
R: If the Slugs are under 21 years of age can I get in trouble for serving them alcohol? Thank you for the info. I'll take a chance that they are older Slugs - if our Tampa Bay area rain ever stops.
I was thinking of twist-tying a gauze pad to the trunk(s) of the plant with Vaseline on the part of the gauze not touching the plant (because it is a petroleum based product) - as a sort of sticky trap, a gooey barrier, slugs would not want to crawl over. Ever heard of this idea? Could it work (if the slugs are still 'staggering' up the plant - after the beer) ? ?
R: We've never heard of the gauze idea. The slugs will not survive the beer. Guaranteed.
R: Probably because I thought it up myself. Was just wondering if you had ever heard of anyone trying ANYTHING like that? I tried the beer and no slugs showed up, but the beer was gone. My wolf-dog may have gotten it. Maybe before the slugs had a chance.
Japanese Beetles
Q: I live in coastal Georgia and have many large azaleas in my yard. I noticed recently that something is eating jagged small holes in the mature leaves, leaving brown edges around the holes. What is it and how do I get rid of it?
A: According to Rodale's "Landscape Problem Solver" Japanese Beetles and Asiatic garden beetles will leave holes that are brown along the edges. However, it says that they attack younger leaves. In addition, you should be able to see the beetles. Hand pick them off, set out beetle traps, or add milky spore to the soil.
More likely, you have slugs or snails that feed at night and leave rasping holes. They like moist areas and live under boards during the day. Rodale's suggests what we have done forever. Beer traps: take the top of a mayonnaise jar or a tuna can and sink it in the ground (so the slugs don't have to climb the sides) and fill it with beer in the evening. If there are not dead slugs floating in the morning, then you do not have slugs.
Moles
Q: Moles!!! They're driving me crazy. What can I do.
A: Moles are after one thing. Food. Removing the food source which is grubs, cut worms, worms and insects might go a long way. Organic methods are friendly to our earth, but tend to be longer to accomplish.
- Plant Castor Beans
- physically trap with bated apple, peanut butter, or cheese
- disturb with mole hills and flush with soapy water.
- smoke them out
- create vibrations
- buy two cats
- pour castor oil (1 tsp to 1 gallon) in the holes
- plant Euphorbia plants
- put kitty litter in the trails.