Curl Grubs in the Compost

Be sure to check out the latest addition to Camden Community Garden when you’re visiting next time.  It’s the “first born” of our new compost bays.  Eventually we’ll have a few set up at various locations around the garden to make them easy for everyone to use.

Our composting workshop was what prompted our new “baby”.  Just like any new baby, our compost bays will require some TLC from all of our garden members. It will need to be turned every week from one bay to another, so perhaps a roster is in order.  The effort that you put into making the compost will be richly rewarded by bigger, stronger and healthier veggies when you use the final product.

During the workshop we learnt that the most efficient composting system was a HOT compost, which is large and is fueled by oxygen and water.  So if we want lots of compost for our garden beds then we need to have lots of materials to make it.  Layering different material when constructing the compost is essential for success. So save up your newspapers or shredded office paper so it can be mixed with lawn clippings and weeds from the site.  A good mix of wet/hot materials and dry materials works well.

We also discovered that a fine example of good compost was already on site!!  This was prepared earlier by Steve Cooper.  He’d been given the good oil and knew to include different materials, so when we unveiled his compost pile from within the the corrugated iron surrounds, we saw some magic at work!

The compost had been sitting for quite some time, so decomposition had progressed very nicely and most of it was ready to use on the garden beds.  But there was one thing we all noticed in addition to the quality of the compost ..... there were a number of curl grubs in it.

Curl grubs in the compost is quite common.  Curl grubs are simply beetle larvae.  They range in size depending on which beetle it morphs into but they all look pretty much the same - a creamy white “C” shaped fat grub with a grey tip at the tail end. Also known as lawn grub, you’ve probably seen them at home in your garden, pot plants or lawn.

Beetles lay eggs in the soil during late spring, summer and early autumn. The eggs hatch into larvae that feed on plant roots or decaying organic matter, so the compost is an ideal home. The larvae grow and pupate during late autumn, winter and early spring usually.

Chickens love eating curl grubs so let some chickens loose on your finished compost before putting it on your garden beds.  If you don’t have chickens then you can sift them out manually as you shovel your compost into the wheelbarrow if there aren’t too many. If your garden bed has plenty of organic material (like good compost) then a few in the garden won’t make too much difference to your crops.

You can attract predatory wasps into the garden with flowers.  These parasitic wasps will also help keep numbers in check.

Curl grubs can sometimes, however, get out of control.  At which time you may feel that it is necessary to do something about them.  The most effective organic approach is to use neem oil.  Eco-neem is available at nurseries & hardware stores or online with the Eco Organic Garden range.

Future workshops are scheduled for:

4 February - Crop Rotation & Moon Planting Cycles

3 March - Companion Planting