How to live with or control mosquitoes

July 02

My wife hates to go outside because she attracts mosquitoes, when I don’t even know there are any around.  Several products are available to repel mosquitoes but how effective are they?  Whether or not they are effective is a good question.  A single test can cost millions.  Some of the tests have been made available to the CDC or EPA.  Test results sent to the EPA are to support registrations of products and may not be available for public  use.  The CDC, Center for Disease Control, has research results and does publish some data for the public.  Below is a summary of products and there relative effectiveness.

By far, DEET-containing products are the top performers and most will last from 2 to 6 hours with a single application. Picaridin is the second most effective product with performance in the 1-3 hour range. Oil of Lemon Eucalyptus are considered botanicals and are often labeled as being “green friendly” (whatever that means!). Cedar oil is employed as a scent to repel mosquitoes. The scant data available suggests that these products only last for 15 to 20 minutes after an application. This can be partially solved by finding a formulation that slowly releases the scent into the air.  There are bracelets or tags that hang on clothing that offer a slow release of one or a combination of the above scents. Citronella is listed on the EPA or CDC lists as a mosquito control product. And some of the new mint oils are also not on the list of effective actives.  A pretty good study, done two decades ago, used citronella candles surrounding test subjects.  The test people got bit as frequently as people some distance away, but with no candles nearby.  However, citronella candles seem to be so entrenched in our culture and used for ambiance with everyone thinking they control mosquitoes.  We will likely continue spending millions a year on the little lanterns and keep buying the oil. 

A unique item was found that supposedly gives off a magnetic or electrical field that keeps mosquitoes away from people.  You simply wear it around your neck and they leave you alone.  My suggestion is to make ankle bracelets incorporating the items so they don’t get my wife’s ankles and legs.  Do these items work?  I really can’t say, but I haven’t invested any money in this company.

Mosquito traps have improved and are recognized as being able to reduce mosquito bites when mosquito populations are medium to low.  The expensive ones that work use CO2, a tiny light and a suction fan to attract, pull in and then kill the mosquitoes.  A rather new method of controlling mosquito activity is modifying air movement! Mosquitoes are very weak flyers and don’t like to travel when air movement is in the 8 to 10 mph range or greater. Therefore, using outside ceiling or side fans in an area can greatly reduce mosquito flight and landing ability.  The fans must be turned to blow on the subjects.  

Our family had a wedding reception at our house last summer.  The weather had been very wet and we had a terrific mosquito problem.  My assignment was to make the yard mosquito free.  The methods I employed were four fold.  First, I used my Black Flag fogger which produces a fog that floats on the air.  Any mosquito will have a minute droplet impinge on their body and the small insecticide dose kills them. The fogger was positioned so the fog drifted across the yard and into the brush and trees around the yard.   Next I directly sprayed the vegetation for several feet around the yard and the lawn so mosquitoes that landed would pick up a lethal dose.  This works, because when resting, mosquitoes land on vegetation and get liquids from the surrounding vegetation.  Third, I made sure any mosquito breeding sites were eliminated or treated so my yard did not provide breeding sites.  Fourth, the day of the reception I treated the yard with a cedar oil product from Green Light, YardSafe Insect Repellant.  The aroma kept new mosquitoes from venturing in to attack our guests.  The cedar oil smell was faintly in the air and lasted throughout the afternoon and evening. No one would object to the pleasant smell.  The result was no mosquitoes at the party.

Do yourself a favor when you plan on going outside. Don’t eat bananas.  Eating bananas makes people attractive to mosquitoes.    They are also attracted to CO2 but we do have to breathe.

The Garden Doc

Growing apples

Apple trees may start bearing every other year.  This is called alternate year bearing and can be avoided.  When apple trees produce every other year they set a huge fruit load that produces small apples and the fruit load may be so heavy it ends up breaking branches.  The fruit load also drains the resources of the tree and it doesn’t develop flower buds for the following year.  A tree that is bearing fruit in alternate years can be brought back into yearly production by managing fruit load with thinning the fruit, proper pruning, and specific summer pruning.

Frosts may cause the blossoms to freeze in the spring about blossom time which will also cause fruit not to set.  You can try keeping some air moving or lightly misting the crop with water a few times during the below freezing temperatures.  Water may freeze and cause branches to break.  Another method to keep trees from freezing is warming the area with fire.  One of my uncles wrapped Christmas tree lights on the branches and the small amount of heat from the lights kept the blossoms from freezing (that’s a lot of work).  The best method is to select a variety that is tolerant of the cold and selected for your environment.

Commercial fruit growers yearly thin the fruit after it is set when the new fruits are about the size of a dime or nickel.  They use commercial products that must be applied at precise rates.  I wouldn’t recommend this be done by amateurs.  Homeowners may have difficulty spraying an even amount of chemical over the whole tree.  If your tree has excessive fruit numbers, hand thin when fruit is about the size of a nickel and before it is the size of a quarter.  Prune until there are one or two fruits per terminal.  The terminal is the group of leaves at the end of a branch.  An old fruit grower said you need 40 leaves to produce one apple.  The fruit will be much larger and you will get a good yield with proper thinning.   When thinning, leave the apple at the very end of an apple bunch.  This apple grew from the king bloom.  In a bunch of blossoms the king bloom is the center and larges blossom and will produce the largest and nicest apple.  By good pruning and controlling the fruit load, you can have fewer apples but each apple will be a lot larger and the over all yield will be a good yield.

If you are bold and want to chemically thin the insecticide, Sevin is used commercially for apple thinning.  Consumer packages don’t include apple thinning instructions.  You will have to figure that out yourselves.  If you over thin you will have no apples.  If you under thin you will have to reapply or thin by hand.  Apple trees often have what is called the June drop where the tree self thins.  Some varieties and trees do a pretty good thinning job by themselves.  Others may have so many apples it looks like the fruit was wrapped around the branches like a rope.

Prune the tree each year to remove excessive branches and any branch that will brush or interfere with other branches.  Fruit should be able to hang without banging other branches. The distance between branches when pruned should be 2 to 3 feet.  During the growing season this distance will close and then you prune again the following year.  Determine whether you want the tree to have a single leader with branches coming off the main trunk or do you want an umbrella shaped tree with several main branches arching over.  When pruning remove all water sprouts.  Those are the shoots that grow straight up but are not the central leader.  Pruning will stimulate more water sprouts to grow.  There are very sophisticated trellising or staking methods for growing apple trees planted at very high populations. 

Trees with alternate year bearing usually don’t produce flower buds because of the high fruit load stressing the tree when it does bear fruit.  Proper fruit load reduces the excess stress so the tree has the strength to produce flower buds for the following year.  Flower buds develop mid to late summer then bloom the following spring and turn into fruit.  Pruning stimulates the tree to grow new growth.  You can stimulate bud production by a light pruning mid July.  Prune 8 to 10 inches of the tips of some small branch that don’t have fruit. The remaining leaf bunches will be stimulated to produce flower buds that will bloom the following spring.

Deer Control

June 11

My yard is home to deer.  Last summer, a doe raised her two fawns in the 50 yards of woods between myself and my neighbor.  In the woods there are three main trails crossing from one area to another.  Every year, the hostas in my yard get grazed, some to the point of looking like they were run over by the lawn mower.  Two years ago, every day lily flower bud except one was eaten just before it opened.  One year a dear ate several tulip flowers and my rose buds.  My fenced vegetable garden had an unsecure gate and a deer got in and ate all the carrot tops.  Deer love carrots.

How do you control deer from grazing in your yard?  Anyone with deer in the area knows how destructive they can be.  They are yard vermin.  Temptation to shoot them runs high but it is illegal, even though I feel like it is similar to shooting rats.  Here are some remedies:

Dogs – Don’t laugh, a good dog and deer don’t mix.  The dog has to be outside and the ability to run helps.

Deer fence – This works for some items but not for ornamental beds.  (Remember to keep the gate closed.)  For deer it must be a 6 foot tall fence.  Electric fences work but they require some maintenance like weed control and the electricity supply has to be reliable.  This is costly and not very aesthetic.

Ultrasound and electronic controllers – Here are words from one rater: “In theory this keeps deer away from the area because they dislike the sound.  However, ultrasonic devices don’t work around obstructions.”  Motion detectors set to turn on a real noise maker like a radio may work.  I have not tried these.  Products are named Deer Gard and Yard Guard. The cost $50 to $100.

Chemical deer repellents – The several types of repellents are those made of putrescent eggs or blood with mint oils, garlic and so forth; hot pepper sprays or capsaicin; products containing Bitrex, a bittering agent deer dislike; and large predator animal urine.  These all have the ability to work rather well.  However, they all need to be reapplied on a regular basis.  Some are malodorous to humans as well as deer.  They also shouldn’t be used on plants used for food.  Product are named Plantskydd, Deer Scram, and Deer Repellent. Cost is $10 to $20 a package.

Motion activated water sprinklers – My neighbor deploys this method with great success.  It does require water use.  The motion detectors and water sprinklers are physical objects in the landscape and some maintenance may be required.  This is one of the more costly methods.

Milorganite – Last year at a large nursery in the Twin Cities at which I spent the day working, I saw Milorganite.  It is a granulated dried, residue from the Milwaukee sewer system sold as an organic fertilizer.  It worked for deer control. Every week after I mowed my lawn, I spread two to three pounds around my yard over plants deer eat.  Not one plant was eaten until a month after I quit spreading it in the fall.  Then the deer again grazed the hostas.  My lilies were beautiful, my summer flowers all had heads on them and there was no browsing anywhere I treated. There is a human smell when you open the bag but after it was spread, I couldn’t smell it in the yard.  Over the spring, summer and fall I used one and a half bags for a total cost of about $15.  It was very easy to spread with my hand held granular spreader and only took 3 to 4 minutes a week.  In addition to deer control it does supply needed fertilizer.

Brown Marmolated Stink Bugs

June 3, 2011

Many articles have been written and much research is being conducted on the Brown Marmolated Stink Bug.  If you live along the I-95 corridor around Wilmington Delaware to Richmond Virginia and over into the Appalachian chain you had stink bugs, especially if you were in a somewhat rural area.  Smaller infestations were found in just about all Midwestern states.  They ruined fruit and vegetables, in the fall they congregated on houses trying to get in for the winter.  They are expected to be a problem in many farm crops and around home ornamentals this summer.  

The term stink bug is not a scientific name, but a nickname because of the unpleasant odor they emit. Stink bugs emit their odor as a means of self-defense and protection against harm. A stink bug’s odor smells very distinct, it is difficult to describe, only to say that it is sour, pungent and unpleasant. What do stink bugs smell like? I’ve heard the smell being compared to rotten cilantro and skunk.  They also stink when you crush them.

They and are expected to be a large problem this summer and fall all over the Midwest..  What can you do?  Protect vegetation, both small plants to trees with an insecticide.  Systemic products like Bayer Advanced Tree & Shrub or Green Lights Tree & Shrub Insect Killer with Safari will kill the bugs if the plant is treated in time for the insecticide to get through out the plant.  When the stink bug chews on the vegetation it gets the insecticide and dies.  There will be some damage when they chew some foliage to get the insecticide.  Other wise you will have to spray insecticide and reapply it about every 2 weeks.  Don’t believe the claims that a spray will last for up to 12 months.  It will only last about 2 weeks on vegetation.  Sprayable insecticides are Sevin, malathion, and pyrethroids which are most of the rest of the products.  These products will only give about 40 to 80% control.  Even if you spray, new bugs will come into your yard regularly.  This fall spray around your windows and doors and possibly the sides of your house to kill the bugs that are trying to get into your house for the winter.  An insecticide spray on the outside of your house will last longer than on vegetation but most decompose in sunlight.  You will have to re-spray once or twice through the fall.

Weeds, Weeds, Weeds, Will I Win or Will They?

May 25, 2011

This morning I weeded a couple of rows of my vegetable garden.  The plants from seeds are emerging but just as fast are all the weeds.  Perennial weeds were about 6 inches tall and annuals were an inch or less.  This post is ways to consider fighting the weed war.  Plan ahead and your battle will be much easier to win.  Perennial weeds were about 6 inches tall and annuals were an inch or less.

For perennial beds plan before you plant.  Before you plant anything, prepare the soil then cover the whole area with a quality weed mat or landscape fabric.  These come in long strips and are available at Lowes, Home Depot, Menards and garden centers.  They come in various lengths usually 50 to 100 feet long and 3 or 4 feet wide and then cut to fit.  Commercial sizes are much wider. After the area is covered cut X’s where your plants will go and plant the perennials.  Secure the fabric with stakes and cover with mulch or rocks to make the garden aesthetically acceptable.  In the future you can move the mulch, cut new x’s and plant annuals or perennials.  The more cuts through the weed mats, the more places for weeds to grow.  The weed mats will last for many years.

If your garden is in a new area, spray with a glyphosate herbicide like RoundUp or Com-Pleet to kill all the existing weeds before tilling.  This will kill the hard to manage perennial weeds.

Using mulch to cover the soil is extensively used.  It also looks very professional.  Some weeds come through the mulch but they can be physically removed or sprayed.  Many people add about 3 inches of mulch.  Experts recommend using about 1 inch of mulch.  A thicker mulch layer will inhibit the emergence of more weeds.  If you plan on using thick mulch take this into consideration and plant plants to be at the depth of the top of the mulch.  The worst item you can do for the health of perennials, especially trees and woody ornamentals, is to heap mulch up around the trunk.  Heaping mulch around trees, kills trees.  Still many people like the look and it is still done.

Weeds that come through mulch can be sprayed with RoundUp or Com-Pleet, but don’t allow the spray to contact the ornamental spray.

You may add commercial bagged topsoil to eliminate weeds.  They may still have a small supply of weeds in even though it comes in a bag.  A local topsoil may be ideal for fixing problem soils but be prepared to deal with a new brand of weeds brought in with the topsoil.

Herbicides are used extensively in commercial real estate.  Homeowners don’t have access to all the product used commercially but still can easily control the weeds.  Preen is most commonly used for both ornamental and vegetable gardens.  If this writer were to rate products, the highest rating for weed control with a granule would be Amaze.  If it is not available in your area, ask for it specifically.  Amaze from Green Light has two herbicides, one stronger on grasses and one stronger on broadleaf weeds.  It will last longer than other products for weed control around ornamentals.  Amaze covers more area per pound of granules and will be cheaper than other products.  Amaze should not be used in vegetable gardens.  There is also a Preen for Southern Gardens that uses dithiopyr but cannot be used in vegetable gardens.  It will control weeds for twice as long as regular Preen.  Some of the commercial crabgrass control products can be used in ornamental gardens.  However, read and follow the label directions before making application.  These products often control many more weeds than crabgrass.

Several companies such as Scotts Miracle Gro sell a similar herbicide as Preen.  One such product is Miracle Gro Weed Preventer.  Most Scotts Miracle Gro products use fertilizer as a carrier which may be an overuse of fertilizer.  A commercial product used in ornamental plant beds is BroadStar or SureGuard, a granule and liquid product containing a new herbicide flumioxazin.  If it becomes available for residential use by consumers it will provide long lasting excellent control of weeds. 

Another way to provide good long lasting weed control is to use one of the commercial products with glyphosate and a residual herbicide.  The most common product is RoundUp Extended Control or SeasonLong Grass and Weed Control.  These products kill all the weeds and lay down a layer of herbicide weeds won’t germinate through.  They will provide about 3 to 4 months of weed control.  If these products are sprayed on existing plants or you get too much on the green bark of young trees and shrubs they will also be killed.  Use with EXTREME caution around existing plants.

The historic way is simply hoe out the unwanted plants with a hoe.  If you are growing a vegetable garden, grow a small size garden, small enough so the weed war is small enough to keep under control. 

Happy Gardening!

Insects To Watch Out For

May 18, 2011

Since most gardens are being planted or already growing, I thought I would help people prepare and watch out for specific insects.  This is a summary of insects to watch out for.

Wire worms – Wireworms live in the soil and can eat the seeds or small plant roots causing the need to replant.  They occur early spring and often are problems in areas turned from sod into a garden.  The treatment is to have insecticide treated seed or apply an insecticide when planting.  An interesting fact is the adults are click beetles.  Catch a click beetle and have fun.

Flea beetles – Flea beetles often are in large numbers about the same time plants emerge from seed.  They are 1 to 2 mm in size, black and jump or fly away when disturbed.  They suck juice from the small plant causing small injured areas.  Enough injured areas severely retard plant growth or kill the plant.  Treatment is an insecticide treatment.

Cutworms – Cutworms usually cause damage early spring.  Damage is recognized as plants that have been chewed on or chewed off at or just above ground level.  They also cause local spot damage in lawns.  They do their damage at night hiding in soil or thick vegetation during the day.  They can be controlled with most insecticides.

Aphids – Aphids love sucking on young tender tissue.  They are usually up to 1/8 inch long, often green to pink and have very soft bodies.  The garden plant most loved by aphids is the rose, where it is usually on the new growth near and on a developing rose bud.  They also are pests of many tree species and a few other garden plants.  They can be a little difficult to control due to large numbers.  Most pesticides control aphids but some aphids have resistance to some insecticides.  Insecticidal oils and soaps are often effective.

Colorado potato beetles – They are a pest on potatoes, tomatoes, and egg plants.  They overwinter in soil and come out when plants are small.  They are about 3/8 inch long as adults with orange bodies and yellow & dark brown longitudinal stripes on the hard shell wing covers.  The larvae are orange and through instar stages grow to about the size of adults.  They simply chew up the vegetation.  They are resistant to most insecticides.  Product containing Merit may work but some locations have resistance to Merit product also.  A new product containing clothianidin may be available for gardeners in a year or two from Green Light. 

Tomato hornworms – They eat all parts of the tomato plant.  They are worms with a horn on the tail end.  They start very small but can grow as large as your finger.  Large hornworms can cause a lot of damage very quickly.  They are very hard to find but occur in small numbers and can be picked off one and a time and disposed of.  Most insecticides are effective in killing the worms.

Cabbage butterflies – The cute little white to yellow butterflies lay eggs that become cabbage or broccoli worms.  Another similar pest is diamond back moths.  Their eggs also hatch and become worms in cole crops.  Cabbage and broccoli worms are generally a mid-summer to fall insect problem.  They are easy to control with vigilant spraying.  Another method of control is to plant a very early crop and harvest before the butterflies become a problem.  Bt insecticides such as Bt Worm Killer or DiPel work very well on worm pests.

Thrips – Many species of thrips occur and infest many species.  The western flower thrip is a severe pest of many flowers including roses.  Chili thrips are a newer pest, infesting peppers.   Onion thrips are common in onions and often cause early death of onions.  This is one of the tougher pests to control because of the large numbers of thrips.  Many thrips have true resistance to many insecticides.  New insecticides containing Safari are now available and give control from the inside out.  Unfortunately, they are not labeled for food use.

Corn earworms and borers – They infest sweet corn and the borers are a major pepper pest.  Adults lay eggs that eat their way into corn ears chewing on my favorite garden crop, sweet corn.  They also drill a little hole in pepper fruits just below the cap often causing the pepper fruit to spoil.  Sweet corn is often sprayed commercially every 2 to 3 days to stop this pest.  Any corn ear with a worm ruins the ear.  Commercially, one infested ear in a hundred ears is not acceptable.  To treat sweet corn in the garden, spray or dust the ears at least once a week starting as soon as the silk appears for three weeks.  Most insecticides will control corn earworms.  Insects are worse the later in the season the crop matures.  When consumers have the opportunity to grow genetically altered Bt sweet corn, you will never see a corn earworm again until resistance occurs.

Cucumber beetles and squash bugs – This is a group of insects that chew or suck on the vines of watermelons, cucumbers and squash.  Often they transmit a virus or bacteria that cause the infected vine to wilt.  A fine line exists between controlling this insect with insecticides and letting bees and other pollinators pollinate the flowers without being killed.  There are many insecticides that work.  As the season progresses these bugs get worse.  Most insecticides will control these insects.  You do need regular sprays.

The new Brown Marmolated Stink Bugs – Good Luck.  This will be covered in a later post, but a lot of insecticides will kill it.

There are way too many insects to discuss in one post.  Sorry if I missed yours.

Container Gardening

May 13, 2011

Living in Fargo, North Dakota as a graduate student I grew hundreds of tomatoes to use for research purposes.  They grew in small pots and were mostly killed in the research conducted.  One lucky plant was hauled home in late fall, planted into a large pot (bucket) and placed in one of two small South facing windows.  It grew despite the very spartan conditions.  There were no insects to pollinate it but I would flick the flowers with my finger tips to move pollen.  The only light was from the window during the short days and the single incandescent bulb in the room.  That tomato never got very large or lush due to limited light, but did produce 23 tomatoes.  The tomatoes were about 1 ½ to 2 inches in diameter but otherwise were very normal tomatoes.  It kept producing tomatoes until the summer when garden produce became available. 

The tomato was grown as a curiosity to see how it would do in a small window. 

A few weeks ago a reader asked about vegetables in pots or small container gardens.

Try it!  You may be surprised at the success of plants.  Plants are like people, they want to grow and reproduce. Plants need only a few basic things for survival and good growth.  They are; a space for the plant to grow with support for the roots to attach to, to hold the plant, water, nutrients and sunlight.  Water, nutrients and sunlight have to be in the right amounts.  The nutrients and sunlight can actually vary quite a lot. 

The container can be just about anything.  The larger the container the more water and nutrients it will hold making life easier.  Pots, buckets, cans, wooden planters, and even a picture of an old boot showed up on the web as  a plant holder. 

Soil – Any good potting soil will be sufficient.  Potting soils are now engineered to hold extra water, provide nutrients for an extended period of time and support the plant via a good mixture of organic materials for the roots to spread out and to grow in.  Hydroponic plants can be grown in soil less environments.  Tubes filled with rocks are used and provide a place for the roots to grow and to anchor the plant.  Water and nutrients are pulsed down the tube at regular intervals so the roots can have what they need.

Most people simply buy a potting soil.  Which is best?  My local greenhouse owner “Little Red” makes his own potting mix, and of course it is the best.  My guess is it is very good but none of you can buy it unless you come to my town.  Major brands are Espoma, Fafard, and the family of products from The Scotts Company, Hyponex, Miracle Gro, Osmocote and Organic Choice garden soils and potting mixes.  My guess is they are probably all good.  Some have a total organic mix or a brand of fertilizer added to differentiate them.  For my graduate research we used 1 part soil, 1 part manure and 1 part decomposing tree bark all mixed in a grinder.  Today’s mixes mostly contain bark, peat moss and some contain a new ingredient coconut coir.  Coconut coir is the fiber from the coconut husks.  Is it a better ingredient in soil mixes?  It works and has good water holding capacity.  But so do the other organic components.  Some claims for holding water are made by adding water absorbing gels that hold lots of water and slowly give it up as the soil dries.

Water – Plants need the right amount of water.  Most plants in pots are overwatered.  Roots need to have oxygen which they get from air spaces in soils.  Overwatering fills those air spaces depriving the plant of oxygen and promoting root diseases such as pythium and phytopthora.  Only water when the soil is dry but before the plant wilts and drops leaves.  Choosing a larger pot helps keep the right amount of water for the plants.  It also makes it so you don’t have to water as frequently.  Provide a pot with holes in the bottom so excess water can drain is not essential but is a great point of success. 

Nutrients - A good soil, including most potting soils come with enough nutrients to provide those needed for several months.  If the plant becomes very large or has been supporting plants for several months, or years, you need to add nutrients.  A good water soluble fertilizer like Green Light’s Super Bloom mixed as directed and applied every two weeks will help the plant continue to thrive. Another fertilizer method is an application of Osmocote every few months to ensure good fertility.  Over fertilizing will cause a build up of nutrients to create a salty soil condition.  When soils become salty the salt holds the water not allowing water to be absorbed by the plant.

Sunlight – The right amount of light is critical and varies from one plant to another.  Most plants need a minimum of 8 hours of sun with 12 to 16 hours being ideal.  My garden gets a maximum of 10 hours of direct sun with some tree shade mixed in.  Direct sun is much better than filtered sun or other ambient light.  A few plants like ginseng, impatiens and azaleas do well with less light in shady locations. Tomatoes will grow with less light but will thrive and produce much better with direct sunlight for more than 12 hours a day.

Recently there have been several commercial variations of plants in pots.  “Square Foot Gardening,” “Topsy Turvy,” and “Potatoes in a barrel,” are examples.  They work but any container large enough to maintain the size of plant will work just as well.  Hanging baskets do very well, except many are hung in the shade so they are limited to shade loving plants.  Just get something to hold the plant, get some soil, and try the plants you want.  Follow the principles above and you will be successful.

The number one vegetable is tomatoes and they do well in pots and provide great rewards.