Category Archives: education

WTF – Black Bindweed

I feel this garden season has been packed with plant identification. In no way am I complaining about this. Plant identification is a pretty enjoyable game to me. When a fellow gardener was telling me about a swift-growing vine with heart-shaped leaves in her home garden, I fought the urge to immediately hiss “bindweed” (Convolvulus arvensis). The weed is from the Morning Glory (Convolvulaceae) family and is a complete terror on the Lot. I agreed to make a visit to help with some pruning, so I pretty much had to find out if I was right or not.

Analyzing the Offender

When I arrived and was able to meet the vine in person, I realized it wasn’t bindweed. I would recognize my Nemesis anywhere, in any growing zone, and this wasn’t it. Yes, the vine was eating the porch alive and the leaves were heart-shaped. However, I immediately noticed what looked like white seed heads in large clusters all along the vine… not a trait of the bindweed we deal with on the Lot.

Black Bindweed covering Lantern

There aren’t many weedy vines in our state, so I started going through some weed ID sites looking for the vine that would be going to seed at this time of the season. Eventually I found a site for a project at the University of Michigan: Burnham, R.J. (2008-2014). “CLIMBERS: Censusing Lianas in Mesic Biomes of Eastern RegionS.” (September 6, 2017).  And that is where I found the name of the plant I was looking for: Black Bindweed (Fallopia convolvulus) of the Buckwheat (Polygonaceae) family.

Up Close and Personal

When ID’ing a plant, there are a lot of clues one can pick up by taking a thorough look at the specimen. Parts of the black bindweed helping me to ID it were:

  • alternate, simple, heart shaped leaves
  • vine, twining from right to left
  • glabrous (free from hair) ocrea (sheath around the stem)
  • roots are non-rhizomatous
  • branching of vine located more near base of plant
  • papery calyx (sepals of the flower)
  • flower understated with no petals

Black Bindweed on Railing

Evicting the Weed

I struggled to find a control method for black bindweed. It’s an  aggressive, annual weed introduced from Eurasia. The plant spreads by prolific reseeding. The seeds themselves are enclosed by a hard shell and can be viable for more than a single season in the soil. In fact, this was the reason my gardener friend inquired about the plant. She said though a crazy climber, the plant was kind of pretty (which it was). But then she saw all the flowers (future seeds) and thought “Oh sh*t.” Yeah, we’ve all done that before.

What we do have on our side when removing this vine is the fibrous root system and the small area of a home garden. Though fairly deep, the roots aren’t a rubbery, rhizomatous system that takes off underground like a berserker gopher. The plant was removed and burned. Next season, the gardener has to keep an eye open in the spring for any new seedlings and pull as needed.

Hey Four Eyes

After a garden fieldtrip to Lake Cliff Garden, we stopped into a neighboring town for lunch and some social time. On the top of a hill near the lakefront, I found this large stand of common milkweed (Asclepias syriaca). Of course I had to go over and see what little critters were enjoying the beautiful, summer day.

Stand of Milkweed

I was not disappointed! One of the insects immediately catching my attention was a colorful, red beetle. I was able to snap a pretty good photo to bring home and use to identify the milkweed resident.

Red Milkweed Beetle on leaf

Red Milkweed Beetle

The insect is Tetraopes tetrophthalmus or the Red Milkweed Beetle. Like many other insects who feed on milkweed, the beetle’s bright color warns predators it is toxic because it ingests the plant. Larvae burrow underground to feed on the roots and overwinter. Adults emerge to feed on leaves, buds, and flowers of the plant and can be spotted in our growing zone about midsummer.

What’s With the Eyes?

Something interesting I read and then found on my photo, was the position of the beetle’s eyes. Let’s zoom in for a closeup!

Closeup of Milkweed Beetle Head

The Red Milkweed Beetle’s compound eyes are bisected by its antennae. One set of eyes is located above the antennae, while the other is located below. In Latin, both the genus and species name translates to mean “four eyes.”

Purring Bugs?!

Another fascinating fact I stumbled upon while cyberstalking the Red Milkweed Bug is that they vocalize. These bugs squeak and purr! A gentleman by the name of Richard D. Alexander wrote a paper in 1957 titled Sound Production and Associated Behavior in Insects. When observed in the lab, the RMB vocalized when going about its day interacting with the milkweed plant and others of its species. It does so by rubbing together structures on the segments of the thorax. I will definitely be leaning in to take a listen if I’m fortunate enough to spot the Red Milkweed Beetle next season.

But Will They Harm Me or My Plants?

The short answer is “no.” A healthy stand of milkweed will not be harmed. If you’d rather not see the beetles, you can remove the milkweed plant from the garden. As with most creatures, if the beetle is not assaulted and manhandled, it will not bite.

References

Michigan State Extension

College of Letters and Science Field Station – University of Wisconsin Milwaukee

Hackberry Nipples

Mrs. A, the friend I visited last Spring in Louisville, migrated back to her native state and is now closer by and in the same growing zone as I. She and her family purchased a modest little farmhouse in a rural area of the state. With the house came a beautiful parcel of land including a veggie lot, small apple orchard, herb garden, mature trees, and established perennial plantings.

Every now and then she’ll ping me with a question about gardening as she is a newcomer to the hobby. She’s been soaking up knowledge like a sponge and I’ve been having a great time chatting with her about all things green and growing. The following was a photo she sent to me from leaves she noticed on a mature tree near the garage. She asked if this was a disease and something they should treat.

073116_hackberrynipple2

Weird, right?! It’s one of those things you poke at with fascination and a touch of “this creeps me out.” There were cylinder-like growths protruding from the underside of the leaves.

ID the Victim

The first thing to do was ID the tree. Many universities have great tree ID keys on their websites. After using the bark, leaves, shape of the tree, and the growing Zone where we are located, we identified the tree as a hackberry (Celtis occidentalis). The hackberry is a hardy shade tree growing up to 60 feet tall. Mrs. A’s hackberry was one of these mature specimens.

What are the Symptoms

Here is another shot of the hackberry leaf. The leaf itself was picked up from the lawn, not from the tree. However, some branches were hanging low enough to notice the leaves were not dry, but did have the same odd growths.
073116_hackberrynipple
Many irregular growths on plants are referred to as “galls.” The plant reacts to a parasite ranging from bacteria to insects, increasing growth hormones. According to the University of Minnesota, “These plant hormones cause localized plant growth that can result in increases in cell size (hypertrophy) and/or cell number (hyperplasia).” The gall is a growth similar to a benign tumor or wart on an animal.

Galls can appear on leaves, stems, twigs, flowers, and buds. This appeared to be a leaf gall, one of the most common in the plant world. UofM summarizes leaf galls as “leaf curls, blisters, nipples, or erineums (hairy felt-like growths) on the upper or lower leaf surface.”

So, this gall growing on the underside of the leaf was a further clue to help Sherlock the situation. The situation seemed hopeful though because most galls are more of a cosmetic blemish than threatening to the health of a plant. Plus, unlike a young plant needing every bit of the nutrients it can collect, this huge hackberry was older and well settled.

Hackberry Gall Psyllids

Searching on The Internets, armed with the name of the tree and the knowledge of galls, eventually landed me on the Nebraska Extension in Lancaster County website. It seemed the culprit was the hackberry gall psyllid.

After overwintering beneath the bark of the tree, adult psyllids  lay eggs on the new growth of spring leaves. When the egg hatches, the young insect begins to feed on the sap of the leaf. This action triggers the forming of the gall, enclosing the insect. The psyllid will remain protected as it feeds throughout the summer.

To Spray or Not to Spray

It depends on the homeowner or gardener as to how comfortable he or she is with the cosmetic alteration of the tree. It was comforting to Mrs. A to know the hackberry gall psyllid was not harming the tree. Because of the large size of the tree and the fact at this stage the galls protect the insects, a foliar spray would have been a waste of time and money. Spraying during spring when the nymphs are emerging would be an option, but the application would have to be repeated over several weeks, again resulting in a huge expense. There are insecticide drenches that can be mixed and applied at the base of the tree during the feeding period of sucking insects. This also is based on the size of the tree so may be impractical due to cost. That money could be put toward new plants! If it were up to this gardener, the tree is not being harmed so I would let nature handle it.