Phlox Plant Bug
Tall garden phlox are looking a little ratty this season thanks to the phlox plant bug. This insect has a piercing/sucking mouth part (similar to aphids) and they will suck the life out of the plant. Damage will manifest as downward cupping, stippling, dead terminal growth, and lack of vigor. There can be two generations a year and they overwinter as eggs on dead phlox stems. To help reduce the insect from reoccurring good fall or early spring sanitation would help remove the eggs. Low impact options would include insecticidal soaps or horticulture oils.
Oleander Aphids
We are seeing oleander aphids in abundance on milkweed. They are bright golden yellow with black cornicles (tailpipes). In most cases damage rarely occurs from feeding. However, they can produce honeydew that can lead to sooty mold which can be unsightly. Most aphids reproduce parthenogenticaly meaning they do not need to mate to produce young. This allows their numbers to quickly explode. Populations can be kept in check by natural predators. If management is needed they can be brushed off with an old toothbrush or strong streams of water.
USDA Hardiness Zone Map Questions
The first attempt to map out zones was done by the Arnold Arboretum in 1927 to show where trees would grow successfully. When you take a look at the map (above) you can see that Omaha was in zone 3. A lot has changed in the last 97 years thanks to improved technology and cartography. The USDA Hardiness Zone map was updated this past winter and most of Omaha shifted into zone 6a (-10F to -5F) while western parts of Douglas county is 5b (-15F to -10F). What does this mean? If you ask ten different horticulturist you will get ten different answers. To better understand; the map shows us the average of the extreme cold and does not reflect weather anomalies. Simply put, we can still get colder than -10F. Recently the Omaha area had lows down to -15F this past January (zone 5b). On February 16th, 2021 we had a low of -23F (zone 4b). When it comes to new opportunities with plants most of us can agree that we should approach them with caution. Just because a plant is cold hardy to 6a does not mean it is adapted to our precipitation, humidity, soil, elevation or has the ability to withstand weather colder than -10F. As my former boss would say: only plant what you can afford to replace.
Burr Cucumber
Burr cucumber botanical name is fun to say Sicyos angulatus . However, it isn’t fun to grow. This native annual vine is not a common weed in the home landscape and is more of an agriculture plant of concern. It can be found in urban green spaces growing aggressively up telephone poles and onto surrounding woody plants. Generally speaking it is considered a weed and management would be preventing the plant from flowering and setting seed. Cutting vines at ground level is a simple way to manage the plant.
Japanese Beetles
Right on cue. Japanese beetles have started to emerge. Jody shared this picture from her yard on Friday June 14th. Here are some important facts about the beetle:
- Grub management is best applied at the end of June. Acelepryn (chlorantraniliprole) is a newer grub option that is becoming the product of choice. Other options include imidacloprid and halofenozide.
- Grub management does not prevent or stop adult beetles from flying into the landscape. Grub management will only protect the lawn and nothing else.
- Paenibacillus popilliae (Milky spore bacteria) only infects the Japanese beetle grub. No recent university research trials have shown applying the bacteria provided any level of management.
- Japanese beetle grubs do not survive well in dry soils. Dry conditions during the months of July, August, and September can increase grub mortality.
- Heavily irrigated lawns create favorable habitats for the beetle larvae.
- Hand picking beetles around 7 PM at night is the most effective time of the day to remove the beetles. This will help reduce the plant from making the distress pheromone making the plant less inviting. https://go.unl.edu/dcij
- Manage adults when they start to feed. Never apply insecticides to blooming plants.
- Adult beetles emerge middle of June through July. They do not all come out at once.
- Adult beetles can live up to 45 days.
- Adults can fly between 2-5 miles.
- Regardless of the plant height, adult beetles will start feeding at the top of the plant.
- Beetles favor feeding locations in full sunlight.
- We do not dispute the fact that the Japanese beetles trap work. They work too well. Each trap has the potential to attract a few extra 100,000 more beetles into the area.
- Mass trapping has been shown to work in agriculture settings. Read more here
