Tuesday, May 2, 2023

Spring Finds 2023


A weakened garlic mustard.  Arrows pointing out insects on
the stem and leaf and a weakened flower stalk.

While out evaluating the effectiveness of winter spraying and pulling up garlic mustard this spring I noticed aphids on the plants that I had not noticed before.  These might be the garlic mustard aphid, Lipaphis alliariae.  These are native to Europe but have been showing up in the US of late.  I first noticed these dark colored aphids on plants that had been sprayed with glyphosate.  As I became aware of them I found scattered populations on the untreated garlic mustard as well.  Plants that were heavily infested with aphids were not coming into bloom.  Fortunately this species is host specific, meaning it only feeds on a single host plant, in this case garlic mustard. If you see them you can report the sighting on iNaturalist or EDDMaps, a web-based app for reporting and tracking invasive species.  

Close up of aphids on a garlic mustard leaf.  Coloration and
markings are consistent with the garlic mustard aphid.

The aphids on this garlic mustard are
interfering with blooming.

The area to the left of the line was sprayed with glyphosate in late February. 
The effects of spraying didn't show up until the weather began to warm in April. 
This photo was taken about 2 month after spraying.

As I mentioned in my last blog post one of my to dos was to spray a number of invasive plants with glyphosate before the native species broke dormancy.  I was a little late in getting this done so I had to be very careful not to spray the emerging native plants.  It took a long time to see any effect of the treatments. It became clear where I had sprayed after the weather got a little warmer and the Japanese honeysuckle started greening up.  The sprayed areas were definitely browner.  However, there is new growth of Virginia creeper, ash seedlings and grasses.  The box elders that were covered with honeysuckle took some damage, but they are now beginning to leaf out.  The targeted spraying technique that I have been using limits damage of non-target species and reduces the amount of pesticide applied but it also allows a lot of target plants to be missed.  As practiced, it is one of several tools I use to control invasives.  Pulling, cutting and replacing are all important components in my battle. While not 100% effective using my technique, it did set back the early growth of Japanese Honeysuckle and garlic mustard and multiflora rose.  This spraying has little effect on Oriental bittersweet, which does not put out foliage until much later. The cut stump method seems to be more efficient for shrubs and climbing vines (less overspray).  I will try to do the spraying in November this year after most of the native have died back.  There are studies that indicate that glyphosate treatments for garlic mustard at that time are more effective than in the spring.

Rattlesnake, or common grape fern, has a distinctive triangular shape

While putting out tick tubes a week ago (this is nearly a month later than I had planned) I came across a fern I had not seen before.  It has distinctly triangular appearance, quite unlike the Christmas and wood ferns that are pretty common here.  A photo sent to the ‘Seek’ app on my phone identified it as rattlesnake fern, Botrychium virginianum.  This is one of the grape ferns, named for the clusters of sporangia on the fertile frond that may look like a cluster of grapes.  The fern that I spotted lacked a fertile frond.

A Christmas fern (left) and an unusual form (right)

The pinnae of this fern are distinctly toothed, many with spiny edges.

Another unusual fern I spotted was in a clump of Christmas ferns, Polystichum acrostichoides.  Usually the margins of the pinnae (leaflets) are nearly smooth.  On this fern the margins of the pinnae were distinctly toothed, many were spine-tipped.  The pinules do have the enlarged lobe at the base, common to Christmas ferns.  So this probably is a variant of the regular Christmas fern.

The blue-green foliage of these twinleaf plants forms an effective ground cover.

I have been working on finding native replacements for vinca in a dry shady location for quite a while.  One plant that continues to impress me is twinleaf, Jeffersonia diphylla.  While its native habitat is rich moist woods, it seems to have found a home in the dry shade of this driveway planting bed.  After taking a year or two to settle in it has been doubling its spread each year for the past 3 or 4 years.  The flowers last for only a few days in early spring but the interesting foliage persists until fall. 

The branching habit of this violet sets it apart from most of the others
growing here. The large, toothed stipules indicate that this is pale violet.

Springtime is when most of the violets come into bloom.  By far the most common here are, appropriately, common blue violet, Viola papilionacea.  So when I saw a white violet in the woods I stopped to examine it.  Besides the white color, what distinguished this violet was its branching flower stalk.  Most violets only have basal leaves.  Checking in my Newcomb’s guide led me to ID this as pale violet, Viola striata.  Canada violet, another similar white violet has yellow coloration in the throat of the flower and lacks significant stipules.

Some of the flowers in my early May lawn.  Most noticeable
 are the Philadelphia fleabane (native) and the bulbous buttercup (not).

 No mow May?  I still haven’t mowed yet this year.  I have been allowing the fleabane and other natives time and space to flower and go to seed.  However, this also allows bulbous buttercup to do the same.  There are several aspects of looking at the ‘No Mow May’ trend.  It is valuable if your lawn contains early blooming plants that benefit insects/pollinators.  Natives like fleabanes, selfheal, spring beauties and violets, can benefit the local insect population.  If your lawn is a near monoculture of turf grasses skipping the mowing in early season will save on gas, but do very little to help the pollinator population.


Saw lots of salamanders in the pool this spring.

After opening the swimming pool this past month I found about a dozen salamanders hanging out in the cold water, about 58°F.  Normally salamanders are tricky to get out, but these were relatively sluggish and were easily caught in the basket skimmer.  These were most likely red-backed salamanders, Plethodon cinereus.  At this size these were probably a year of two old, old enough to be looking for a mate.