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The Plant Medic

  • Once popular, flowering pears now seen as invasive
    Q. I have heard recently that flowering pear trees are invasive. Is this true? A. There is increasing evidence that flowering pear tree seedlings are spreading rampantly into wild disturbed areas.
  • Beware: Ticks are rampant this year
    Q. Our family went for a hike in a wooded area recently. When we came back to the house, we found several ticks on our dog and the kids. Are ticks bad this year? A.
  • 3 words about rolling your lawn: Don’t overdo it
    Q. I need to ask your opinion about rolling the lawn. I have been told by neighbors that it does no harm to the lawn. I have seen on some Internet sites that it can hurt the lawn. Who is correct? A.
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Take steps to stop early blight on tomatoes

Q. The leaves of my tomatoes are beginning to yellow and they also have spots on them. My eggplant leaves are riddled with holes, and my beans look like they are scorched. I am ready to give up. Please help us!

A. It can be difficult to maintain a healthy garden during drought periods. It’s a little strange but we actually receive more samples of plants at the extension office with fungal issues during dry periods compared with wetter periods during the summer. This phenomenon occurs because people are just watering more and with water often come fungal issues in the garden. Other insect pests of the garden love the hot dry weather.

It sounds as if your tomato plants are becoming infected with early blight. Early blight is a common fungal disease of tomatoes, with yellowing spotted leaves that appear first at the bottom of the plant. If you do nothing, the disease will move from the bottom of the plant up – until the entire plant looks as if it had been hit with a flame thrower. No one wants this effect on their tomatoes. There are several options that will help to control early blight and other common fungal leaf diseases of tomatoes.

Make sure to water in the morning and try to water at the ground level rather than sprinkling the foliage of the plants. Use a mulch of untreated grass clippings, compost, pine needles or clean straw under and around the plants. Mulching will help prevent fugal pathogens from splashing up onto the plant from the soil. Pick off any leaves close to ground level that look like they could be infected. Use a fungicide registered for use on tomatoes. Serenade is an organic fungicide that can be effective. Ortho vegetable disease control is also an option. Apply a fungicide at the first sign of disease on your tomatoes, and follow label instructions.

It sounds as if flea beetles are the issue on your eggplant. They are difficult to control. I have found that regular dustings with Diatomaceous Earth can really help reduce the leaf damage. This organic product is made from crushed diatoms – a prehistoric sea creature that is mined in Western areas of the U.S. This material basically dries out the insect. Sometimes it can be difficult to find this product, although most garden centers and even some health food stores (such as Three Rivers Co-Op) carry this product.

Mites can be a real issue on beans during hot dry periods. The leaves appear scorched, with a bronzed appearance. Looking closely at the leaf, one can sometimes observe fine webbing. Regular dustings with Diatomaceous Earth can help control mites. Products containing permethrin (Eight dust) can also be effective. Wash off the mites with a high pressure water spray periodically.

Hot, dry summers can lead to difficult problems in the vegetable garden. Don’t give up – just manage the garden drama if and when it appears.

The Plant Medic, written by Ricky Kemery, appears every other Sunday. Kemery is the extension educator for horticulture at the Allen County branch of the Purdue Extension Service. Send questions to kemeryr@purdue.edu.

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