The Afghan pine problem in Austin

Twenty years ago, the Afghan pine was considered the miracle pine for the Austin area. Let me preface that by saying that pines do not thrive in the Austin area; the pH is wrong. Pines, along with camellias, rhododendrons and azaleas, love acid soils. This is why none of these plants grow here in the native soils. The reason that Afghan pine, or Eldarica pine, Pinus eldarica, was considered the miracle pine for this area is because it can survive in alkaline soils. It is a Middle Eastern desert tree which means it is also extremely drought tolerant as well.  This should make it ideal for this area, right?  As it turns out, dead wrong!

These trees were introduced to the US from Afghanistan in the early 60s, especially in dry arid desert states like California, Arizona and Nevada where they do fairly well.  They get minimum rainfall there and enjoy the dry low moisture environment. 

This tree survives in its native environment in areas like Afghanistan with only 20 inches of rain per year.  The Austin area gets on average 30 to 60 inches per year, which is way more than in the past. In addition, people were planting these trees in irrigated landscapes, adding to the additional water they get on a regular basis.

After local nurseries had been selling and planting these trees for some time, and the trees got upwards of about 10 years old or so, we started to see major decline. At this age and older, these trees started to defoliate from the bottom up. The problem is that by this time the trees had seen some growth, and now not only were they a major landscape component, but also a removal that typically required a tree service.  With these removal and replacement costs, the local tree nurseries stopped selling them.

The problem these pines get here is diplodia, or tip blight, Sphaeropsis sapinea.  Without going into the lifecycle of this fungus, it is important to note that too much water to this particular pine makes the fungus (already present in this area) more active and that the Afghan pine has no natural defense against it, being a desert tree. So the fungus basically kills the tree slowly, working from the bottom up by destroying the branches from the tips inward to the trunk. Additionally, there is a moth that attacks and hollows out the buds on the end of the branches, called the tip moth, which also kills the limbs. 

These trees were also widely planted because they were farmed and sold as Christmas trees as well, and as live trees were often planted after New Year. Well, that’s basically the Afghan pine story. The moral of the story is, basically, that introduced species are not always as good as they seem. Maybe it’s better to stick to trees we already know work in this area and have been growing here successfully. Pines don’t grow in the Edwards Plateau because the limestone is just too alkaline. Anywhere out of the limestone belt; San Antonio, Dallas or Fredericksburg for example pines can thrive, or of course Bastrop, famous for pine forests and quite close. I think the smart choice is just to avoid pines altogether in the Austin area!