The Butchart Chronicles : July 14, 2014

Pest Management

At The Gardens, we started using an Integrated Pest Management (IPM) program, as early as the 1980's, to help control pests in environmentally sound ways. IPM is a method of reducing pest populations to acceptable levels by using a variety of control types in a socially and environmentally conscious, dynamic manner. We are constantly striving to improve our processes.

Plant spacing and transplanting
IPM at The Gardens involves the use of cultural, mechanical, biological and chemical controls to manage pest problems preventatively. One cultural control involves properly spacing plants to allow good airflow and sufficient light. Mechanical controls include hand weeding and the removal of plants which are chronically plagued by pest or disease problems. To that end our gardeners are merciless about removing diseased plants and exacting about spacing of plants. We start most of our plants in our own greenhouses (26 in total) and transplant them outside giving them space and light to develop properly before they are put into their proper display beds.

Fuchsia under attack by spider mites
The above photo is of a fuchsia leaf under attack by spider mites, 'stippling' is obviously apparent here from the feeding actions of the mites. To avoid this, one of the products we innoculate them with is Stethorus punctillum, a very tiny lady-beetle that eats spider mites. 


Biological controls are widely used here. They use natural enemies to control pests and diseases.  A great example of this in action was on May 8th of this year we released 800,000 predatory mites (mostly Amblyseius cucumeris) in the Rose Garden for thrips and rose midge control.  300k were soil mites and 500k were foliar mites.  Below is how we receive mites - in this case 25,000 per litre, from our Biological Controls supplier.

Stratiolaelaps scimitus

We followed this up on May 14th with a release of 600 Aphidius in some greenhouses, which are used to control aphid populations. As one can see, they are a very tiny parasitic wasp.

Aphidius release
Other things we do to promote general plant health here are:

  • Regular soil testing and amending of soils throughout the gardens - we compost everything compostable at The Gardens, from flowers past their prime to kitchen scraps such as apple peels and potato skins.
  • Improving our irrigation systems for optimum distribution.  We use over 110 million litres of water per year, most of it gathered on our own property from wells and resevoirs.  We use drip irrigation, where possible, to save water.
  • Applying nematodes to our lawns to reduce the population of cranefly larvae is a yearly rite. For example, on May 9th this spring we applied 500 million nematodes to some of our lawns against the aforementioned cranefly control. The photo below is just one drop of water with many hundreds of nematodes encased within it.


Watch King 5 News' video on IPM at The Gardens:  Bugs deployed as pest assassins at Butchart Gardens