Garden almanac, Garden Pests

Common Issues in Gardens this Week

Let’s have a chat about some common issues in gardens this week and how to tackle them!

First off, if you’re growing cucumbers, there are two diseases you should be on the lookout for anthracnose and wilt. Anthracnose is a fungal disease that causes irregular spots on cucumber leaves. If you’ve had problems with this in the past, it’s a good idea to spray your plants with a garden fungicide to keep the leaves healthy.

Cucumber wilt is another nasty issue. It’s caused by bacteria carried by striped or spotted cucumber beetles. This bacterium clogs the plant’s water tubes, leading to sudden wilting and eventually killing the plant. As soon as you spot these beetles, it’s time to spray them with Sevin or a similar insecticide. Also, remove any wilted plants to prevent the disease from spreading.

For those of you growing hollyhocks, you might see brownish or reddish spots on the leaves. This is a sign of rust, a fungal disease. Unfortunately, once you see these spots, it’s too late to treat the plant, but it will still bloom. To prevent rust, spray with a fungicide in late May and make sure to clean up plant debris in the fall.

This year, you might notice a lot of frost cracks in trees due to the unusual winter we had. These cracks happen because warm temperatures in February allowed the sap to flow, which then froze and caused the cells to explode, creating vertical cracks. There’s not much you can do except wait and see if the cracks heal themselves. Trees with smooth bark, like young red maples, are particularly prone to this. Just remove any dead bark to let air circulate around the wound.

If you’re dealing with little grasshoppers in your garden, especially in rural areas, try keeping the area around your garden mowed short as a barrier. If grasshoppers become a bigger problem, using bait can sometimes help.

Common Dog Tick
Lone Star Tick
Black-legged Tick

On a different note, I recently gave my dog, Magdelin, a Bravecto chewable for ticks, and within three days, I didn’t find any more ticks on her. There are three types of ticks in South Dakota to be aware of. The most common is the dog tick, which can carry tularemia. Then there’s the Lone Star tick, which can carry various diseases, including Alpha-gal syndrome, making you allergic to red meat, and tularemia. Lastly, the Black-legged tick (deer tick) is known for carrying Lyme disease. If you spot Lone Star or Black-legged ticks, you can participate in South Dakota’s tick survey to help track their progression. You can find more information on the survey at the South Dakota Department of Health’s website: Tick Identification | South Dakota Department of Health (sd.gov).

Garden almanac, Garden Pests

Aphids Coming to Play this Week

Aphids are coming to play this week. These are tiny, mostly green soft-bodied insects sucking out the plant juices. Many aphids are only plant-specific to the plant family they attack. Like rose aphids attack only plants in the rose family. There are a few aphids that will attack a wide range of plants. As they suck out the plant juices the leaves will curl and wrap around them offering some protection. To treat for aphids, use high force sprayer attachment on a hose to knock off the insects and do this several times a week. You can also use Neem oil or insecticide soap.

People have been having various problems with roses. The main problem is because of our wetter weather, is black spot. This is a fungus causing black spots on the leaves often killing the leaf. Use a fungicide to protect new or unaffected leaves. There are varieties less susceptible to this fungus.

Another disease on rose not as common is virus complex. This encompasses three different viruses. Most likely they will not kill the rose but will make the leaf unattractive. No roses are immune to the virus which is transmitted by insects. It is best to remove the affected plant.

Lastly, if your rose leaves have round holes removed along the edge of the leaf, you have carpenter ants or bees. I would just let them be because they will not cause any harm.

Garden hacks, Garden Pests, This week's garden questions

This Week in the Garden (May 30)

This week in the garden, a few interesting weeds are cropping up. Let’s take a closer look at each one and share some tips on dealing with them:

First up is a weed that’s a flat mat of leaves with little blue flowers, growing about a foot across and a few inches high. This early bloomer is a type of Veronica, also known as Speedwell. It’s common and can be easily pulled up.

Next, there’s a viny weed with tiny, hooked hairs that stick like Velcro and a square stem. This is known as bedstraw or sticky willy. Historically, it was even used by pioneers for bedding and pillows. It’s another weed that can be pulled out without too much trouble.

The third weed you see has beautiful blue to violet flowers and resembles phlox. This is wild phlox or Dame’s rocket, often seen along roadways and tree areas. Like the others, it’s a prolific seeder but can be removed by hand. It does make for a great pollinator.

On a different note, you might have noticed some vibrant hydrangeas in greenhouses like blue, pink, and white. If you’ve ever wondered why your blue hydrangeas sometimes turn pink or white the next year, it’s all about the soil pH. Hydrangeas bloom blue in acidic soils (pH below 5.5), purple in slightly less acidic soils (pH between 5.5 and 6.5), and pink or white in neutral to alkaline soils (pH between 6 and 7.5). If you want to keep the deep blue color, plant in soil with extra peat moss and fertilize with a high-acid fertilizer. There are over 75 varieties of hydrangeas to choose from, and most of them prefer moist, shady conditions, especially in the afternoon.

There has been some curling in the leaves of young vegetable plants, like tomatoes, flowers, and some young trees. If no aphids exist, the culprit is likely herbicide injury, possibly from a weed and feed product on the lawn or spray drift. Sometimes, plants can recover if they’re not too badly affected, but being early in the season, you might want to consider replanting or replacing them. If you’ve used a sprayer for herbicides, mark it clearly so it’s not used for anything else. Also, if your lawn has been treated with herbicides, wait for two or three mowings before using the clippings as mulch.

As for lawn care, a good mowing height for bluegrass is 2.5 to 3.5 inches. As the summer heat ramps up, raising the height to 3.5 to 4 inches can help keep the soil cooler and retain moisture. Remember to never cut more than a third of the grass blade at a time to keep your lawn healthy.