Pine Rosemary Drowning?
Answered by: Conrad Richter
Question from: Rauchig
Posted on: January 29, 2001

I bought some Pine Rosemary with my last recent order this past spring from Richters. It has been doing good until just recently. It is starting to get black needles and I suspect that it might of received too much water. It sits outside in a pot. This fall/winter we have received a lot of rain. After each rain event I do empty the saucer under the pot and allow the water to drain out. I suspect this has not been enough as I think the rain has taken its toll.

Rosemary turning black is a common occurance. Please check our website for some past articles on the subject. Please go to http://www.richters.com and follow the link to "Q and A" and then search for "rosemary".

Excess water is one of the most common causes of decline and death in rosemary over the winter months.

Scale insects and mealybugs can also cause your plants to turn black when infestations are heavy. These pests secrete a sticky substance that attracts fungi that cause the black discoloration. If your plants feel more sticky to the touch where the black color is evident then suspect a pest infestation. Scale and mealybugs are very hard to get rid of so you will need to some experienced help to help you to decide on a course of action. In cases of heavy infestation, sometimes the only alternative is to discard the plant.

I have been for a few months unsuccessfully trying to root cuttings from it. It still has some new growth that has not turned black. I was hoping for some pointers on how to root this herb. I know to use sterile sand. How do you make sure the sand is sterile? What kind of conditions does this herb like for the cuttings to root? I plan on buying the book you offer (by Thomas DeBaggio item #B4280) with my next order.

The book will be a big help.

It is not necessary to sterilize the sand. It is important that it be "sharp", clean and definitely not from a salt water beach. By "sharp" it is meant that the sand is not so fine that it packs hard over time; such sand will restrict air movement in the root zone.

The key when taking cuttings is to avoid swings in temperature and moisture. The cuttings must be pressed in hard enough to anchor the cutting adequately. Participants at my propagating workshops learn are shown a simple way to test if the cutting is adequately anchored: if the cutting doesn’t slip when tugged slightly by a leaf then it is okay.

Rosemary can develop hard woody stems. Cuttings with woody stems take a lot longer to root than cuttings from softer, more active growing tips.

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