Have a Catalog offer ? Click Here

Put out the Welcome Mat for Stag Beetles!

Q. Back in July, Lynda in our fair city of Bethlehem PA, wrote: "I heard a show where you seemed to prefer Cedar Mulch over black or red hardwood mulch. As I recall, you didn't have much good to say about the hardwood mulch. This year I bought Cedar Mulch instead of our usual black hardwood mulch containing Preen.

"I was very pleased, as it seemed to spread easier, go much further per bag and is better for the soil. My 'question' is: This year we have seen far more stag beetles crawling up the sides of our house, patio and deck. We have lived here over 30 years and only remember seeing two in all that time, one of which was back in a wooded area on an old tree stump. Now we are seeing three or four a day!

"Could the cedar mulch be attracting them? There are no wood piles near our home, and our post and rail fence is not near the house. I understand the beetles are harmless and don't attack plants, but I really don't want to see them crawling up the walls every time I go outside. Your thoughts?"

Q. First, let's go back to your opening, as it gives me a chance to strongly repeat my objections to dyed wood mulches. Those of us of a certain age will remember when there was no {quote} 'mulching season', and no one would dream of covering their landscape with weirdly colored wood chips.

Simply put: Landfills either stopped accepting wood waste or began charging a premium to accept it. So builders and contractors took their huge piles of construction debris, old pressure treated wood decking and insecticide soaked shipping pallets to a newly emerging racket where machines would chip up the trash wood and then soak it in some kind of unregulated dye that would either turn it black or the color of a condemned Burger King.

Then, in bulk or in bags, it was foisted onto homeowners as 'the new look', proving P. T. Barnum correct in more ways than I can count. To make matters worse, this trash wood is almost always applied too deeply on the landscape. Why? Because the landscaper gets paid by the load, not by what's right. If one yard of {quote} 'mulch' would provide the recommended one of two inches of weed-preventing material, five yards would provide a huge profit and smother the landscape by preventing air and water from reaching the poor plants imprisoned below. It's all about the Benjamins, baby.

Other downsides are dye runoff, especially from the black junk, which often smells suspiciously of petroleum and creosote. Not to mention the 'nuisance molds' (like the home-staining and impossible to remove artillery fungus) that breed in the trash, and the outgassing of unhealthy airborne organisms like aspergillus, making the 'mulch' unhealthy for people with breathing problems.

And adding the chemical herbicide Preen to the mix officially makes the resulting landscape a witches cauldron of lung disease and cancer.

The question always follows: "Well, what SHOULD we use?" Studies have shown that two inches of high-quality compost will prevent weeds just as well as two inches of toxic wood mulch, while feeding the life in your soil and plants, managing rainwater brilliantly and causing no potential health problems--and hey; it's even black! Another great choice is pine straw; available in many lengths and natural colors, it has been the mulch of choice down South for many generations and is now available in the North.

Anyway, back to the beetles. Stag beetles are large (up to three inches long), have science-fiction level mandibles and are an endangered species in the US and Europe. ("Stag beetle" is a general term, as there are 24 different species in the US.) Their fearsome mouth parts are used only to fight off other males, which would make a neat video.

(And yes, a scary-looking adult might bite you if you pick it up and taunt it, but they're not venomous and you deserved it.)

Unlike the highly beneficial ground beetles that feed on slugs and other garden pests, the awesome looking stag adults do not feed, and live only long enough to mate. Their life cycle consists of a female laying her eggs in rotting wood, the more decomposed the better. The eggs hatch into large grub-like larvae and chow down on the rotting wood, helping it become fresh soil. They can remain in this stage for one to three years. In the wonderful world of beneficials they are considered 'decomposers'.

I suspect that Lynda's recent invasion was the result of females being attracted by her rotting wood mulch a few years back, with the adults eventually emerging in late Spring through early summer, just as they're supposed to. It's also possible that their large-scale emergence was the result of the cedar mulch--it resists rotting, so they have no interest in it. Its natural aromatic oils could have also acted as a repellant and encouraged them to escape in droves.

They climbed up the house because they mate up high, generally in the canopy of trees. And finally, be assured that they're no threat to sound wood; they're only interested in soft, rotting wood.

Item added to cart