Question by Jaeme K.
We planted lavender 2 summers ago along the north facing wall of our house. Some of them took and the other half died so we dug them up, put stones for drainage under them, and replaced them. We then had more die so I dug out the dirt and replaced it with new top soil and half of them have died again. What is happening? I thought lavender was a hardy plant.
Sarah's answer
Hi Jaeme,
The most common cause of lavender death is a water-related issue. As they come from a dry, sandy region of the Mediterranean, they like it warm and dry with good airflow and free-draining, slightly alkaline soil. As you have some that do well and others that don’t, it would seem that you may have an area in your garden that is soggier than others and this could be causing the problem.
Another issue could be the presence of heavy clay soil. The stones under the planting hole would have helped a little but you may need to further address the drainage issue by fixing the whole problem area. The roots grow out beyond the planting hole and so adding grit to a larger area than just the planting hole would be beneficial.
An alternative is to build up the soil and plant on a mound of free draining soil. Avoiding mulch will maintain a drier environment and giving them wide planting distances can help with good air flow.
The problem may not just be the water, but these conditions are perfect for phytophthora to cause root rot disease. By not controlling the moisture issue, the disease can linger in the soil and will affect the next plants so changing the conditions will reduce the risk. If all else fails, you might want to consider growing them in pots. I hope this helps.
Cheers Sarah
