Our final What's That? Wednesday blog features yellow nutsedge. Yellow nutsedge is generally more of a problem in lawns than vegetable gardens. However, you may encounter it in the garden as it can come in with soil amendments. Nutsedge is a sedge, meaning it has a triangular stem and 3 leaves at each node while grasses have rounded stems and generally have two leaves. Nutsedge reproduces by underground rhizomes and nutlets. For a few plants, it’s easiest to just pull out the sedge, then watch the area. New plants will emerge from what was left underground, so pull every couple of weeks. Eventually the plant will run out of underground energy. Here are a couple of links with more complete information on nutsedge from Purdue and K-State Research and Extension.
Blister beetles feed gregariously on tomatoes, potatoes, beans, peas and many other vegetable crops. They are ash gray or striped to blackish. When crushed, they release a substance that can easily blister skin. Care and gloves are needed to handpick beetles off plants into a bucket of soapy water. Blister beetles generally move on after a few days.
Grasshoppers are indiscriminate. They will eat most anything. Some years it seems like they are everywhere. Other years, they aren’t so bad. The differential grasshopper and the two-striped grasshoppers are the most common seen in the vegetable garden. Control is best achieved when the insects are young and generally group together to feed. Here is information on their control from K-State Research and Extension if you feel control is needed.
Flea beetles are an annoyance on many host plants. They especially love eggplant, melon and beans. They are very small, jumping beetles---thus their name. They can vary in shape and color. Flea beetles are generally worse earlier in the growing season. If infestation is high enough, plant health will be stunted and can wilt. Here are a couple of good articles from K-State Research and Extension and University of Minnesota Extension about flea beetles.
Fusarium and Verticillium are two wilt diseases that affect the vascular system of plants. Both are soil borne and the best defense is to plant varieties that have some resistance to these pathogens. On a tomato label, you will see letters behind the plant variety, “Celebrity VFNT”. The V & F stand for resistance to fusarium and verticillium wilt. For more information on ways to deal with these wilts, here are links from K-State Research and Extension and University of Maryland Extension.
These 3-4” caterpillars like to eat tomato leaves and other solanaceous crops. It is the larval stage of the five spotted hawk moth or sphinx moth. These are the large 4-5” moths you see flying around from time to time. Often you can just handpick the caterpillars off or plant an extra tomato plant and move to it. If you see the caterpillar with white projections from its body, leave it on the plant or move it to the tomatoes in the Rows for the Hungry. The caterpillar has been parasitized by beneficial insects called braconid wasps. They use the caterpillar as a food source and then hatch to parasitize other hornworms. Hornworms can do damage, especially when there are many of them. One or two will not significantly hurt your tomato plant. Allow those that are parasitized to stay on the plant as the wasps hatch and will attack the very small hornworms that are not noticeable. To read all about it, here’s a link.
Tomato cracking results in some varieties of tomatoes more than others. It appears as either radial from the stem or circular around the stem. It is due to uneven movement of water in the plant. Maintaining even, adequate moisture through mulching is one of the best ways to prevent cracking. However, some varieties that have thinner skins may crack when there is a downpour due the rush of water movement from the roots into the plant. Certain cherry tomato and heirloom varieties are notorious for this with their thin skins. It can also occur with uneven watering. While we can't control when it rains a lot, we can alleviate tomato cracking with consistent and even watering and mulching. Some years are better than others. Here’s a link to tomato cracking from K-State Research and Extension.
Growing tomatoes, peppers, squash or melon is sometimes frustrating when all the new fruit you are anxiously anticipating rots. Blossom end rot is not a disease, rather a physiological disorder in the plant. It is most often seen when conditions in temperature and soil moisture change rapidly, drought stress, root injury and excessive Nitrogen fertilization. The plant gets confused and cannot move calcium in the plant to the right places. This sometimes occurs even when growing conditions are favorable. However, the condition corrects itself in a week or two and further fruit development is unaffected. For more information about Blossom End Rot, here’s a link from K-State Research and Extension.
Japanese beetles have quickly become one of the most detested insects of all time. They are indiscriminate and feed on a multitude of vegetables, ornamentals, trees, and plants. A lot of research is being conducted to combat these gregarious feeding insects. There are options for control that depend on the plant being attacked, the amount of infestation and your level of time. Note there are many websites that have the answer/product/cure/trap for Japanese beetles. When researching online, find a trusted source, such as .edu or .gov or .org, that has actual research and not just anecdotal evidence. Here are a couple of sources I have found to be updated on a timely basis and filled with fact-based information.
The bane of every gardener growing zucchini, squash, pumpkins and winter squash. Egg masses are found on the underneath side of the plant leaf. They can be squished with your finger to control the number that hatch. Scouting the plants is the best way to keep the pest under control. Good garden sanitation is highly important to reduce the places and food sources for overwintering nymphs and adults. Here are a couple of links from K-State Research and Extension & University of Minnesota with more information about squash bugs and control measures.