If your sago palm -- actually a cycad -- looks like it has a bad case of dandruff, or worse yet, has turned completely dead brown, you’re not alone. Sago palms, once popular in local Japanese style gardens, have been so plagued with cycad scale in recent years that many landscapers have given up on them entirely. Nurseries used to have to keep up with the demand for the cycads; now frustrated gardeners practically have to con someone to take theirs away.
Cycad scale is difficult to treat with chemical controls since the scale has a protective hard covering and it resides on the undersides of fronds. A brochure on cycad scale from UH CTAHR instead recommends relying on the natural and highly effective biocontrol by a tiny black lady beetle, Rhyzobius lophanthae. You can check with your neighbors to see if anyone has the beetles on their cycads. If they do, you can initiate a beetle relocation program to speed up the process – just snip off some fronds with the beetles and then place the fronds on top of your affected cycad. If you don’t do this, however, you probably will eventually get the beetles anyway if your infestation is bad enough. I ended up just boloheading all the fronds and waiting for a new flush, which also works.
However, then there’s the heartbreak of reinfestation. For this the president of the Hawaii Island Palm Society, Dr. Don Hemmes, recommends that you get yourself some coffee. No, not a double espresso, but coffee grounds cast off from your favorite barista. Spread a thick layer of coffee grounds on the soil around the base of the sago palm, and waiter, waiter, percolator, no more cycad scale! Why does it work? Hemmes says the theory is that cycad scale spends part of its life cycle on the ground, and for some reason it seems to hate coffee, thus the infestation cycle is broken.
Of course, I had to try this out for myself because I need lots of excuses to hang out in coffee shops, especially because I’m a tea drinker and write bad poetry. The good news: As you can see in the top photo, so far my sago palm is flushing out and still looking fabulous, and trust me, it smells like Starbucks. The bad news: People are catching on to the free coffee ground remedy, so you have to go early in the day before it’s all been cockaroached. So far my poetry hasn’t gotten any better, either.