Weekly Garden Newsletter May 21, 2013

May 21, 2013 - Kim’s Weekly Garden Newsletter

http://www.examiner.com/gardening-in-detroit/kimberley-willis

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These weekly garden notes are written by Kim Willis, unless another author is noted, and the opinions expressed in these notes are her opinions and do not represent any other individual, group or organizations opinions.

Hi Gardeners

Allium in bloom.

It was 90 degrees yesterday, last Monday we had freezing temperatures, by the end of the week temperatures should be back down to chilly range, what a roller coaster ride.  Keep an eye on the sky and an ear on your weather radio today and tomorrow as this wild weather can stir up some mean storms.  We do need some rain; I got only trace amounts here overnight.   My sweet corn is all planted; it just needs rain to grow.

My hanging basket of fuchsia was blown down last night and it was barely wet.  I left it down on the ground until this weather is over and watered it well.  You may want to take yours down; the wind can be very destructive to hanging baskets.  If you only received a tiny bit of rain like I did make sure to water those hanging baskets well, the wind and heat will suck them dead in no time.  Even a modest rain may not wet a full hanging basket enough; the foliage and flowers shed the water off unto the ground instead of into the pot.

Make sure to keep all transplants watered well until we get some good soaking rain.  This heat is very hard on the newly planted.  My grandfather always made little newspaper hats for each tomato transplant, and he planted 2-3 dozen each year.  The hat gave them a little shade and helped them through the transition from indoors to outside.  I used brown mailing type paper I saved from a shipping box to cover my plants this week.  If your transplants wilt, try to shade them for a few days and keep them well watered.

Yes, my tomatoes are planted, (although I am still looking for a certain variety.) The lilacs are at full bloom, which generally means it’s safe to plant the tender things outside.  I am holding off on the dahlias and on putting out the houseplants.  Be a little watchful of the weather reports this weekend, I see some nights with lows down to 40 or lower predicted and that could mean some light frost. 

The verdict is still out on whether there was extensive damage to the fruit crop from last week’s freezing temperatures.  MSU fruit experts say even a 50% loss will be tolerable, because the trees were so loaded with blossoms this year.  I see some minor loss on my own apples, but overall it doesn’t look too bad.  Grape shoots may have been damaged by the cold, but the plants should recover.  Some strawberry crops were lost.  Let’s keep our fingers crossed that no more freeze/frost events occur.

Eastern Tent caterpillar nests are being seen here and there, although around me it doesn’t seem to be a heavy year.  These pests can cause some cosmetic damage but rarely warrant chemical sprays.  The best way to get rid of them is with a hose; spray them out of the tree.   Or if you can reach them pull off the web and crush the worms.

Things are rapidly coming into bloom because of the heat.  I have late tulips and alliums in bloom and my pink knock out rose is blooming.  In the woods the hawthorn is blooming quite nicely.  The mulberry is blooming, although its bloom isn’t pretty like other fruit.  The ground is purple with the blooms of ground ivy and violets, then accented with the sprays of yellow rocket.  The lilacs are gorgeous this spring, but they won’t be around much longer in this heat.

I have planted some of my containers, I found some very pretty pink and white variegated verbena, which I planted with pink and white Argyranthemums.  The Argyranthemum needs a good common name.  These plants are actually tender perennials, which this frugal gardener is going to try and overwinter inside this year.  They are an example of a plant that you didn’t see much even a few years ago.  There are many new plants on the market.  It’s a good year to explore some of them.

The impatiens problem

Impatiens Downy Mildew

Thirty years ago, believe it or not, impatiens were pretty new as bedding plants.  People were just so happy to have a good annual plant for shady areas.  When I was running the garden shop at Kmart we often sold out of them and people would be waiting for them as we took them off the truck.  Until recently impatiens sold for more than other annual bedding plants. 

It’s a shame that impatiens are no longer a good choice for gardeners to use as a bedding plant.  In the last few years a fungal disease, impatiens downy mildew reared its ugly head and last year the disease made it to Michigan.  I have seen a few impatiens plants here and there this spring but most greenhouses were smart enough not to stock them this year.  They want their clients to be happy with their purchases and they want to keep the disease out of their greenhouses.

Downy mildew will kill impatiens plants in a week or so.  If you had it last year it’s in your soil and will be for years to come.  You need to find a substitute for impatiens that suits your conditions.  I have a link to my article that will give you more information about impatiens downy mildew and a picture under more information below.

It’s important to say that New Guinea Impatiens are resistant to downy mildew and should be ok to plant.  Their higher cost doesn’t make them a good bedding plant sub though.  There are also a few hybrid impatiens that are resistant on the market but they are scarce and expensive. 

If you find bedding impatiens somewhere that aren’t already infected- the disease often starts in the greenhouse, you didn’t have the disease last year and you spray the plants faithfully every week or so with a fungicide from the day you plant them to fall frost, you might keep them growing.  The cost of the fungicide would probably be more than the plants.

Polka dot plant

It’s better to pass on any bedding impatiens you may come upon and choose another bedding plant.  Shade choices are somewhat limited, wax begonias, tuberous begonias, the various begonia hybrids, coleus, caladiums, torenia could work.  Polka dot plants will give color in shade or sun.  Fuchsia comes in upright varieties but is a bit expensive for bedding. The more sun you have the greater your choices will be.  The newer variety of snapdragons may be just right for partly sunny areas and salvias work good in partial shade also.  Lobelia, abutilon, and heliotrope will also work in partial shade.

Plant some sweet alyssum to control aphids

We talked about companion planting just last week and I ran across this interesting research involving sweet alyssum this week.  Researchers were looking for something to help control wooly apple aphids in apple orchards and an organic solution was ideal since many insecticides that control aphids are being phased out or banned or the insects are becoming immune to them.

Research done at Washington State University found that planting sweet alyssum among apple trees attracted large numbers of predatory insects and spiders especially hoverflies, ( remember that “trick” question on the Master Gardener exam anyone?)  Hoverflies love to munch on aphids.  To their surprise researchers found the aphid population was greatly reduced in just one week. 

Beneficial insects that prey on aphids and pollinators are greatly attracted to sweet alyssum.  These insects often eat some nectar along with their “meat” and sweet alyssum has that to share. It’s the hoverfly larvae that eat aphids, the adults feed on nectar. The researchers found helpful insects and spiders were on the sweet alyssum plants almost immediately.

I am thinking that sweet alyssum might be helpful in any area where aphids become a problem and you don’t want to use chemical sprays.  Roses, for example, often have aphid problems.  Just plant some sweet alyssum in full bloom near affected plants and draw the good guys to the rescue.  Since it may be hard to find later in the year you may want to buy some and plant it in pots that can be moved near aphid affected plants when needed.  Or plant it through the garden as a helpful preventative.

What is "Hugelkultur”?

Hugelkultur is actually an ancient way of making raised beds that is again becoming popular with European gardeners and which has now spread to the US.  It involves turning piles of brush and wood scrap into gardens by layering on lots of compost, manure and soil, right on top of the brush. 

The piles are often 3-5 feet high and are planted with vegetables and flowers.  Eventually the brush breaks down and it’s a good way to hasten decomposition of woody material while giving garden plants a boost.  Raised beds are generally warmer and drain better and can be easier to work on.

I am a raised bed gardener but to me hugelkultur looks like a lot of work and a lot of problems. What about the critters who live in brush piles?  I have planted things like pumpkins and gourds at the edges of brush piles and let them cover it.  My current huge brush piles are in the shade however, and wouldn’t be great for gardening.

Why Asian Lady Bugs are so successful

Everyone knows that Asian Lady bugs far outnumber native Lady bugs in the environment wherever they exist.  They are a problem in the US as well as Europe because they invade homes in huge numbers and may contaminate fruit crops, especially grapes, making things like cider and wine taste bad.  There has been a lot of controversy as to why the Asian Lady beetle is so successful over the years.

Recently researchers have discovered that the Asian Lady Beetle carries a tiny parasite in its hemolymph, the fluid a lady bug secretes when annoyed or threatened.  The Asian Lady beetle is immune to the parasite, but other native lady beetles die when infected with the parasite.  It’s common for lady beetles to eat each other, when Asian Lady beetles eat other lady beetles they thrive, but native species that eat the Asian lady beetle die.  It is also believed that the parasite can be transferred to native lady bugs in other  ways.  The parasite is not harmful to humans but it does produce a protein in the Asian Lady beetles hemolymph called harmonine which interests scientists studying immune system responses and could be an immune system booster.

Crazy Ants

Fire ants have caused much grief for southern gardeners since they worked their way up from South America many years ago.  Now a new invading ant is taking over fire ant territory, and since it may survive cooler weather better than fire ants, might become a problem for northern gardeners if it is carried north.   This ant, Nylanderia fulva, is also called Rasberry Crazy ant (named for the discoverer, not the fruit, hence the spelling) but the official common name is Tawny Crazy ant.  It too comes from South America.  It’s a non-descript, reddish brown medium sized ant.

They get the name Crazy ant because of the huge erratic colonies they build up; often the Crazy Ant population in an area will be 100 times more than all other ant species combined.  They also seem to move erratically in their search for food. They eat anything, including other ants, and eliminate all competing species, even fire ants.  The worst thing about them is that unlike fire ants they invade homes, often in the thousands, and are very hard to control.  They often damage electrical systems and equipment by eating components or shorting them out. 

The key to keeping them from spreading north is to watch for ants hitchhiking in things like potted plants, camping equipment and RV’s.  These ants do not fly at any stage of their life so their spread is solely by foot travel or hitchhiking.  Be very careful with nursery plants you receive from the south, particularly those from Texas and Florida.  While they may have been inspected, there’s always a chance a crazy ant could slip through.   And if you visit the south please be very careful not to bring ants back with you.

Potato famine re-visited

All those plant geeks who carefully dry and preserve specimens have done us a favor or at least helped enlighten us about an old problem.  Scientists using new gene sequencing techniques were able to take specimens in herbariums (plant museums) that were from potatoes infected with late blight during the Irish potato famine and sequence the genome of the blight. 

There are many strains of Phytophthora, the fungus that causes late blight.  The researchers were able to determine that the strain that caused the Irish potato famine in the 1840’s was a unique one, which they named HERB-1. It’s gone from our fields now and hopefully will not reappear.

Potato blight probably was carried to Europe in the 16^th century from the Toluca Valley, Mexico.  It took many years for the deadly strain that caused massive changes in Ireland’s population to evolve.  Over a million people died of starvation because of their dependence on potatoes as a food source, and around a million people migrated out of Ireland during the blight years.  Ireland’s population has never recovered to pre-blight numbers.

Late blight on tomatoes

Late blight is still a problem, both for tomatoes and potatoes, as gardeners know, and scientists worry that another extremely virulent strain will evolve similar to the Herb-1 strain.   While millions may not starve if this occurs it will severely affect the economy.  It’s important that gardeners help farmers by controlling late blight and reporting any cases that seem to be late blight to your local USDA office.  I would say report it to the Extension office but in most Extension offices now all you would get is a blank stare and maybe a phone number to a hotline staffed by volunteers. 

Do your garden gloves contain lead and your garden hose phylates?

Recent research from a Michigan based non-profit that investigates harmful chemicals in household items is being widely publicized in the media during the opening to the  garden season.  The Ecology Center has publicized the results of tests on garden products on its website http://www.healthystuff.org/

The report states that some garden gloves tested contained lead and phylates and that garden hoses could deliver a toxic soup of lead, phylates and other chemicals when water was left in the hoses in the sun.  (Phylates are chemicals that are from plastics, especially PVC’s and are known to be carcinogenic.) 

Certainly drinking water from such hoses might be hazardous but I’m not sure how hazardous the garden gloves would be unless you have a habit of sucking on them. It could be that some chemicals would be absorbed through your sweaty hands.  The gloves that were tested were those that had “rubber” coatings or those small grip dots and I do like my Mudd gloves, which are “rubber” coated on the palm.

Chemicals in hoses are more serious.  I would never drink from a garden hose after reading this.  I’m a bit worried about watering my animals from them. The less expensive PVC, vinyl or plastic hoses all give off phylates.  Brass nozzles leach lead into hoses- of course plastic nozzles leach other chemicals.  Whether watering your food plants with these hoses is a problem remains to be seen.

The report recommends that hoses be allowed to run for several minutes to flush out chemicals before using on food plants or filling pet dishes.  It suggests that people switch to “food grade” or “drinking water” grade hoses, which are made from safe substances.  They are more expensive than regular hoses and you will probably have to look for them in the sporting goods or RV supply section of the store rather than the garden shop.  I would also avoid brass nozzles or other fittings.   Things that are supposed to be copper often contain lead also.

Heliotrope could be used in place of impatiens in partly sunny areas.

Beware of crazy ants and hugelkultur

Kim

Garden as though you will live forever. William Kent

More Information

Impatiens Downy Mildew

Read the examiner article by Kim Willis

Almost every gardener has grown impatiens in a shady or semi-shady spot in the garden. Impatiens is known for long lasting color in the garden or in containers and until recently had few insect and disease problems. Recently however a new disease for impatiens, downy mildew, is causing concern for growers and gardeners alike. Some parts of the country are not affected yet, but the disease has been found in Michigan, in fact it is becoming a problem in many areas.

Impatiens downy mildew, Plasmopara obducens, is a fungal disease that prefers cool, moist conditions. Heavy dews and high humidity favor its spread. It can spread by windborne fungal spores or by contact. 

Read more about the symptoms and what to do at this article:

http://www.examiner.com/article/new-disease-confronts-gardeners-impatiens-downy-mildew