One of the first issues tomato growers experience is Tomato Leaf Roll. It comes as a shock to gardeners as they are so happy that their tomato plant has grown quickly and looks great, then all of the sudden, bam. I liken it to the awkward teenage years. The plant’s top growth has outgrown the root growth. The plant is out of balance, like an awkward teenager with disproportionate arms and legs. The plant realizes it needs to cut back on leaf area for a bit to focus on root growth, so it rolls its leaves. Some varieties have a tendency to do this more than others. The condition corrects itself over a few weeks. To learn more about it, here’s a link from K-State Extension and Research.
Harlequin bugs are orangeish-red and black mottled insects that can do a lot of damage on cole crops, tomatoes and potatoes when in high numbers. They feed on the plant sap, causing stippling of leaves and distortions in the heads of cabbage and brussels sprouts. Their eggs are very interesting. They lay a group of 6 barrel shaped black and white eggs on the underside of leaves. Here are some links from University of Maryland Extension and K-State Research and Extension.
If you grow any cole crops—cabbage, broccoli, cauliflower or kale—you know that little green worms can wreak havoc on your plants. Early scouting and control are key to managing the pest. If you see the brown or white butterfly flying around your plants, they are looking for places to lay eggs and you will have worms eating your cruciferous vegetables soon. Here are links from K-State Research and Extension with detailed information about the cabbage looper and imported cabbageworm.
A summer weed that needs your attention now! Note this information is for lawns only.
For most of Kansas, crabgrass typically begins to germinate around May 1. Therefore, April 15 is a good target date for applying the preventer because it gives the active ingredients time to evenly disperse in the soil before crabgrass germination starts. Since the weather varies from one spring to the next, and with it the timing of crabgrass germination, it is often better to base timing on the bloom of ornamental plants. The eastern redbud tree is a good choice for this purpose. When the trees in your area are approaching full-bloom, apply crabgrass preventer. A follow-up application will be needed about 8 weeks later unless you are using Dimension (dithiopyr) or Barricade (prodiamine), each of which will provide season long control.
Control of crabgrass after it has emerged is more difficult but products containing quinclorac (Fertilome WeedOut with Crabgrass Killer, Ortho Weed-B-Gon Plus Crabgrass Control, BioAdvanced All-in-One Lawn Weed and Crabgrass Killer, Drive, others) are usually effective. Clippings from lawns treated with quinclorac should be returned to the lawn or discarded. Do not use clippings to mulch vegetable or flower gardens as they can harm garden crops.
Information from KState Research and Extension
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.