Do Plants Repel Mosquitos? by Donna Duffy

Photo courtesy cdc.gov

 Ask any gardener – they will tell you that it’s a buggy year. The mosquitos seem especially ferocious this summer, which made me wonder if there are any plants that will repel mosquitos. Here’s what I learned from CSU’s research.

Photo courtesy everydayhealth.com

Rumors and misinformation abound regarding plants that will repel mosquitoes in home landscapes. Common plants purported to repel mosquitoes include catnip, peppermint, rosemary, marigolds, Eucalyptus and Artemisia species, to name a few. None of them will repel mosquitoes by merely growing in a landscape. The volatile oils purported to have repellent properties are released when plants are crushed or burned. No data exists to support their effectiveness as repellents. Check out Plantalk’s publication Do Plants Repel Mosquitos for more information. 

Since we can’t depend on landscape plantings to repel mosquitos, the next best thing is to try to repel them by other means. To keep mosquitoes away during outdoor gatherings, burn Citronella candles. Lemon grass, Cymbopogan nardus, a course grass-like plant, contains Citronella oils. Burning candles with wicks saturated with the herb, myrrh is also quite effective at keeping many insects away. In fact, ancient Egyptians used myrrh as a fumigant.

If insects such as mosquitoes have already become a problem, many herbs can be used directly on the skin as repellents. Infusions of 50% Chamomile and 50% Elder leaves dubbed on skin are effective for up to 20 minutes. Infusions are much like making tea, boiling water is poured over the herb and the herb/water mixture is then left to steep for 10 to 15 minutes. The remaining liquid is strained and used as the repellant.

As well as infusion, other properties of herbs such as their essential oils can be used as repellents. Essential oils such as Lavender, Tea tree oil and Citronella from the stone root, Collinsonia canadensis can be worn on the skin and in hair to effectively keep mosquitoes away. It is best to dilute these powerful essential oils in a little olive oil and test this new mixture on a patch of skin before applying to ones entire body. More information can be found in CSU’s publication Plants Help Keep Mosquitos Away.

Don’t let the mosquitos chase you indoors – grab a repellant and make your stand!

Deadhead Flowers for More Blooms by Carol King

July can be an exciting month in the garden. The results of all the hard labor in the spring are beginning to be evident: lots of blooms, especially monarda, black eyed susan, shasta daisy, day lilies, lavender, Russian sage and yarrow; the annuals are looking great and the grass is still green enough!

I spent Sunday deadheading, pinching, cutting back, and disbudding. I know this sounds like torture techniques performed on some poor wretch in a medieval novel, but these actions are just what most blooming flowers need. These methods will increase and provide continuous blooms throughout the season. They also help to keep the garden tidy; flowers compact and help you get that special blossom you want to win the prize in the county fair!

Jeffco Horticulture Staff Member Utley Takes on New Challenges by Jacki Paone

Horticulture Agent , Curtis Utley with Master Gardener Clinician, Allison Millich, present at the Joint Meeting of the Board of County Commissioners and CSU Extension Advisory Committee in June. County Manager, Ralph Schell, in the background.

Curtis Utley, a member of the CSU Extension Horticulture staff in Jefferson County since 2003, has been promoted to Extension Horticulture Agent.  With the promotion come additional challenges in Extension reporting, supervision, writing and program delivery.

Psyllids Are Coming! Plant lice on Tomatoes by Patti O'Neal

Adult Psyllids photo Michigan State University Extension

Reports of sightings of this insect pest in Northern Colorado has set the alert for us on the Front Range.  The potato/tomato psyllid  is a member of the family known as “jumping plant lice” and is very damaging to tomatoes in particular.  It is time to start monitoring your tomatoes on a regular basis for evidence of this pest in your garden. 

Psyllids do not overwinter here in the cold climate of Colorado.  They blow up from Mexico, Texas and Arizona.  Some years are worse than others. And because they are found in one place does not mean they are in another.  Monitoring is the key.  When they are here, they can do a great deal of damage to tomato and potato crops. The home gardener is not exempt and should be on alert to catch this pest before it gets out of hand. 

Happy Fourth! Nature's Fireworks!

Master Gardeners in Service: Plant Select Research and Display Garden by Michele Loudis

Delosperma (Alan's Apricot), photo courtesy Plant Select

The Plant Select program is a great resource for area gardeners because it tests and selects the best plants for our interior West’s challenging climate.  Spearheaded by Colorado State University, Plant Select collaborates with Denver Botanic Gardens, growers, landscape professionals, and public gardens to find resilient and tough plants that flourish in our fluctuating temperatures and dry, windy conditions.  And the Colorado Master Gardeners in Jefferson County help!

Ridding the Garden of Mosquitoes by Carol King

Mosquito photo cdc.gov

We have had a lot of rain over the past several weeks.  While the rain is welcomed, the fallout can be an abundance of mosquitoes. The best time to manage mosquitoes is when they are in the larval stage. This stage, called wrigglers, lives in shallow water and feeds on microorganisms. They can be found in used tires, wheelbarrows, birdbaths, saucers under pots, ornamental pools and other places that hold standing water. Colorado Department of Public Health and Environment’s Fight the Bite website recommends the following steps for reducing the mosquito population. 

Mosquitoes lay eggs in still water, which hatch in 7 to 10 days. If standing water is eliminated weekly around the property, many  mosquitoes will be kept from breeding in the first place. Here are some things you can do:

• Remove standing water in ponds, ditches, clogged rain gutters, flower pots, plant saucers, puddles, buckets, equipment and cans. Empty or flush out containers weekly to reduce or eliminate the larvae.
• Check for items that might hold water including wheelbarrows, leaky air conditioner hoses, pool covers, tarps, plastic garden sheeting, and trash.
• Change the water in birdbaths weekly.
• Use mosquitofish (mosquito-eating fish Gambusia can be released in ponds) or mosquito dunks to prevent mosquito larvae from growing in small areas of standing water.
• Avoid mosquitoes at dawn and dusk when the bugs are most active. 
• Wear socks, long-sleeved shirts and long pants while outdoors.
• Apply insect repellent with DEET. Follow directions carefully.

For more information about complete mosquito management, check these fact sheets:

http://extension.colostate.edu/mosquito-management/

http://www.ext.colostate.edu/ptlk/2029.html

http://www.fightthebitecolorado.com

Spittlebugs in the Garden by Carol King

Spittlebug Froth photo UC Davis

While weeding near my bee balm (Monarda), I saw several patches of  a frothy white substance on the leaves.  Upon further study, I discovered that I have a small infestation of the spittlebug.  Aptly named, the white froth is what the immature spittlebug or nymphs surround themselves with as they feed on plant tissue.  Adult spittlebugs are inconspicuous, often greenish or brownish insects, about 0.25 inch long. 

While spittlebugs suck plant juices and can distort plant tissue and slow plant growth, they do not seriously harm plants. As they don’t cause significant damage, just wash them off with water if their appearance bothers you.  Otherwise, enjoy yet another fascinating bug in action!

Here’s more information:  http://www.ipm.ucdavis.edu/PMG/GARDEN/VEGES/PESTS/spittlebugs.html

Don't Forget to Thin Your Seedlings! by Amy Bubar

Photo courtesy vegetable-gardening-online.com

Your vegetable garden is finally in!  Now, don’t make the mistake of neglecting your labor of love.  Those seeds tend to sprout and grow faster than we often realize, so once your seedlings are a few inches high they may need to be thinned out to make room for their roots to grow. It may seem disheartening to pluck from the ground something that you nurtured to life, but thinning is important to help reduce competition for water, light, and nutrients by nearby plants.  This will allow space for your roots to expand morph into the crop of savory delights they were destined to be!

Cottonwood Cotton by Carol King

Photo CSU Extension

The first wisps appeared last week.  Soon we will be sweeping up big piles of the stuff. As it warms up, it will be sticking to our sweaty bodies; we will be spitting it out and wondering when will it all end. What you say? Well, cottonwood cotton of course!! Planttalk Colorado provided this information about cottonwood cotton.

"Cottonwood trees are dioecious, meaning they have male and female flowers on separate trees. Cotton shed by female trees in June is often so abundant that it turns nearby lawns white. Heavy snows in winter promote plentiful new growth. This in turn fuels abundant flowering of both male ("cotton less") and female (cotton-bearing) cottonwoods in the spring. Flowers on female trees, after being pollinated by wind-borne pollen from male trees in April, develop small green capsules that split open in June to shed small seeds carried by wind-borne "cotton".

An Invasion of Flea Beetles by Donna Duffy

Flea Beetle - photo courtesy CSU Extension

I was working in the yard this morning and noticed an abundance of tiny, shiny, jumpy insects. After some research, I discovered that they were flea beetles. Once I identified them, I started seeing them in my neighbor’s yards as well. So I turned to CSU Extension and discovered Fact Sheet 5.592: Flea Beetles.

Native Perennials by Audrey Stokes

Mirabilis multiflora, Desert four o'clock

Governor Hickenlooper has just proclaimed June 10-16 as "Native Plant Appreciation Week"! For more information and a list of related events, visit the Colorado Native Plant Society's webpage.http://www.conps.org

It's a great time to add native plants to your landscape! Following are some helpful facts and tips from CSU Extension by I. Shonle, L.G. Vickerman and J.E. Klett (4/14).