Native Plants

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Friday - May 01, 2009

From: Dallas, TX
Region: Southwest
Topic: Compost and Mulch, Diseases and Disorders, Shrubs
Title: Older leaves yellowing on Savannah holly in Dallas
Answered by: Barbara Medford

QUESTION:

I planted a Savannah Holly in Dallas, TX in the Fall of 2008. It has new growth and some white buds all over it, but some of the older leaves are turning yellow and dropping off. Is this normal?

ANSWER:

There are thirteen members of the genus Ilex (holly) in our Native Plant Database, but none of them have the common name "Savannah." That is probably a trade name assigned by a grower to a hybrid of North American natives Ilex cassine (dahoon) and Ilex opaca (American holly). Even though both parents are natives, the "x" indicates a hybrid, and we do not have hybrids in our Native Plant Database.

According to the USDA Forest Service website Ilex x attenuata 'Savannah', the yellowing leaves sound like symptoms of chlorosis. Ilex opaca (American holly), in particular, likes acid soils, which you are not likely to have in Dallas. The problem is probably due to alkalinity in the soil beyond the plant's preferences. The alkalinity in the soil keeps the soil from accessing trace elements in the soil. this leads to iron deficiency. Suggested fixes were sprays of iron chelate, sulfur, and iron fertilizer. We prefer adding compost to the soil and mulching the roots with shredded wood bark, on a continuing basis. The compost will help with access to the trace elements, improve drainage in the soil, and help hold in moisture. The mulch protects the roots from heat and cold, holds in moisture, and as it decomposes, continues to amend the soil.