Saturday, November 23, 2013

Insects of the Garden - Cabbage Worms

This pest, commonly known as the cabbageworm, was first noticed on my Brussels sprouts (Brassica oleracea var. gemmifera) on June 23rd.

This worm is the larva of a small white moth known scientifically as Pieris rapae (or commonly as the cabbage white moth).  The female moth lays eggs on the undersides of leaves of specific host plants which include those in the family Brassicaceae (mustard family).  Cabbage, Brussels spouts and cauliflower are very susceptible to damage from this moth's larvae in that the worms hungrily devour the plant's foliage leaving behind skeletonized leaves that can no longer serve any purpose to the plant. They also leave behind lots and lots of dark green poo.  So gross.  As if skeletonized leaves and diminished plant health aren't enough of a reason to rid your plants of these worms!  Who wants to pick through layers of worm poo to harvest their veggies?  And let me just tell ya, it will start to pile up.  So here's what you do...

If you look closely at the center of this photo you'll see a lovely dark green cabbageworm turd!

Go out and buy yourself some "BT", which is Bacillus thuringiensis.  It is a naturally occurring bacteria that kills larvae of some caterpillars including cabbageworms, tomato hornworms and tent caterpillars. The best part is that it is considered organic and is safe for humans and animals.  I bought this small bottle of liquid BT from a local landscape supply store.

You mix a small amount of it with water in a spray bottle and douse down your plants, including the worms.  The BT paralyzes the insect's digestive system which causes it to stop feeding and it eventually dies.  The Colorado State University extension office has a great fact sheet on BT here.

BT can also be found as a powder that you dust onto the plants and worms.  The store where I bought this bottle didn't have the powder form and I'm left wondering if the powder would have been easier to use.  I ended up mixing up too much and it went to waste, as the directions say you must use the mixture within a week of adding water, otherwise the bacteria lose effectiveness.  The powder most likely would have prevented waste.

I found that the BT worked great.  I didn't see any sign of cabbageworms within a day or two after application, but they eventually came back.  We noticed a lot of the white Pieris rapae moths flying around the property all summer, so I knew I would eventually have more larvae.  That means you just have to keep spraying the BT every couple of weeks, which is no big deal.  I just wish the mixture would hold its potency longer so I could use the same batch through a few applications.  I'll have to keep an eye out for the powder form once this bottle runs low.

Pieris rapae moth larvae

Soil Testing

While studying to become a Master Gardener I learned the importance of soil testing for the home garden.  Every three to five years soil should be tested to determine nutrient levels.  Without the proper nutrients plants will not thrive, just like people.  Our county's extension office offers free soil test kits, which you can learn about here.

I bagged up my soil and mailed it to Calmar Labs (a little later in the season that I should have, but better late than never) along with a check for $14.00.  Within about 10-14 days an envelope arrived with the following results:

As you can see, the test revealed that the soil in my raised beds was very high in phosphorus.  The lab recommended amending the soil with 3 pounds of nitrogen per 1000 square foot, 7.5 pounds of potassium per 1000 sq ft, and only 0.6 pounds of phosphorus per 1000 sq ft.  The square footage of my 3 beds totals 96 sq ft, which is only a tenth of the unit of measurement, so I would use .3 lbs (4.8 oz) nitrogen, .75 lbs (12 oz) potassium and only .06 lbs (.96 oz) of phosphorus to get the levels to a normal range.

Over the past season or two I've been trying to determine the cause of the brown crispy spots on certain plant leaves, shown below.

Heuchera (Coral Bells)
Image on the left was taken when the plant was first planted in Fall 2012, image on right was this past June 2013

Damage to Hosta sp.

This damage could very well be due to nutrient deficiency, as, after the correct application of fertilizer, my Heuchera started looking much healthier.  The brown crispy spots are gone and the plant has filled out nicely, looking very lush instead of gangly and sickly.

In the spring I plan to fertilize the other beds in attempt to improve the soil quality for my other plants that have looked less than lackluster, including the poppy that I mentioned here.

Wednesday, September 25, 2013

Bloom Update - Week 26, 2013

June 23 - 29

Asclepias tuberosa
Butterfly weed

Last year this plant hosted many Monarch butterfly caterpillars, which I discussed here (updates posted at the end of each post).  Sadly, this year I have not found any signs of larvae or adult Monarchs anywhere in my garden, but I've recently learned that I'm not the only gardener missing the Monarchs. Last week famed author and garden blogger Margaret Roach posted this article and podcast featuring Dr. Karen Oberhauser of the University of Minnesota Monarch Lab where they discuss the diminishing population of Monarchs and possible reasons as to why.  Take a look/listen to find out more.

Yellow Asiatic Lilies

In 2012 these Yellow Asiatic Lilies bloomed in week 24.

Campanula carpatica 'Blue Clips'
Blue Clips Bellflower

This was my first full season with this Campanula that I planted last spring.  I have two clumps in a bed in the front yard and don't give them much attention, yet they seem to do well.  The flowers are very small, maybe only about 1" wide, but they are rather abundant.  The foliage is very short and dense - at least at this point.  If the plant follows the Sleep, Creep, Leap growth pattern I should have more exciting news to report in the next two seasons.

Leucanthemum superbum
Shasta Daisies

These Shasta Daisies must make for a tasty treat, because shortly after taking this photo the petals were eaten off just like last year.

Pink Asiatic Lily

The yellow version of this plant (shown above) has greatly outnumbered the pinks, as I started off with 6 bulbs of each color but had only one stem of pink emerge this season while I had at least 8 stems of yellow.

Lilium longiflorum
White Easter Lily

My brother-in-law brought this plant to our house a few years ago at Easter.  After it finished blooming I planted it in the flower bed on the south west side of the house.  The cultivar most commonly grown today for commercial production is Lilium longiflorum 'Nellie White,' so that just may be what this is, but I didn't think to record the name when it was gifted to me.

The flowers have very beautiful, pure white petals that shimmer a silvery sparkle in the sun and their fragrance is wonderfully abundant.  It is a native to southern Japan that got its start in US commercial production shortly after World War II.  Now over 95% of the world's Easter Lilies are produced in an area along the US Pacific Coast near the Oregon/California border where the climate is ideal for the propagation of these bulbs.


These were all inherited with the house when we moved in back in 2008.  They aren't my favorite because the blooms only stay open for one day (hence, the common name Daylily) so they don't work well as cut flowers - unless you want to go out every morning and cut fresh blooms to replace yesterday's shriveled mess.

The flowers are pretty to look at though and vary in size from 3-5" wide.  The plants are also very easy to care for - basically maintenance free beside some dividing every few years.

Thursday, August 15, 2013

Summer Containers 2013


Here's a photo of one of my summer containers taken on 6/23/13.  This container contains one of each:

Bottom Right:
Proven Winners Lysimachia nummularia 'Goldilocks' (commonly known as Creeping Jenny)

Bottom Left:
Calibrachoa 'Aloha Kona Mandarin' (commonly known as Million Bells)
Closely related to and often confused with the Petunia

Blooms of Bressingham Euphorbia polychroma 'Bonfire' (commonly known as Cushion Spurge)

Canna x generalis 'Tropical Bronze Scarlet' (Canna Lily)


Flower of Canna x generalis 'Tropical Bronze Scarlet'