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Holly bush problem #734764

Asked December 02, 2020, 2:57 PM EST

I believe I have an American or English Holly bush that isn’t looking healthy. It has been next to a Boxwood for at least 19 years. It just started looking this way about a month & 1/2 ago. We had a maple leaf weed that was growing inside the boxwood that got removed today. What is wrong with it? We really don’t want to lose this prickly beast.

County New York

Expert Response

It sounds like your holly has been infected with a fungal disease known as holly leaf spot, sometimes called holly tar spot. It can be caused by several different fungi, but the symptoms are similar: the leaves develop black, brown, or yellow spots. Eventually, the infected leaves fall off the plant, leaving your holly bare and spindly. Leaf spot usually develops during wet spring weather, and the leaves begin dropping throughout the summer and fall.

The good news is, holly leaf spot is rarely fatal, and your bushes will likely recover if you take steps to keep the problem from getting worse. The plant damage comes from the stress of losing leaves, so treatment and prevention focus on protecting new holly leaves so that the plant can recover. Here’s how to go about it.

Remove Diseased Leaves: Gently shake your holly, or lightly sweep with a rake, to encourage as many diseased leaves to fall off as you can. Then bag up the leaves and throw them away. You can probably put them in a really hot compost pile, but it’s generally recommended to throw diseased plant debris either into the trash.

  • Soil: Well drained loamy soil that is slightly acidic. If your soil is very heavy, add some organic material to lighten the texture and improve drainage (Compost, a few inches on the soil, water in).
    Conditioning the soil is probably one of the most important steps for plant health, making the soil well-drained, and nutrient rich after conditioning.
  • Water: Hollies like a moderate amount of water, usually adequately provided by rainfall. Water weekly during drought, and early in the day before mid day.
  • Mulch: Several inches of pine bark mulch to prevent freeze-thaw damage to the shallow roots. Apply mulch in a circle as wide as the branches.
Fungicides may help reverse the earliest stages of leaf spot but are mostly used as a preventative when new buds are forming in the warm growth season on unaffected leaves.

Hope this helps. Happy holly days...
An Ask Extension Expert Replied December 03, 2020, 9:07 AM EST

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