- Author: Teresa Lavell
Most of the readers of this blog are familiar with the term IPM or Integrated Pest Management. For those who are not familiar with the term it is a big picture approach to gardening and pest management that starts with the least toxic steps first. At the heart of IPM is diagnosis. I learned this, again, this week. I have a row of 4 gardenias planted in a foundation spot under my kitchen window. They have been limping along for a few years now. To my eye, they looked to be deficient in nutrients of some sort or another. So I fed them food for acid loving plants. I waited a while, feeding on a regular schedule, but they never seemed to flourish. Over the course of months I added a compost top dressing, sprayed with a foliar-feeding, tried compost tea and waited. Nothing seemed to help. Someone in the house even gave them a good pruning to see if that might help. It did not. The UC IPM website says optimum conditions for growth are “rich soils with acidic pH” and “well- drained soil.” I decided to try digging the plants up to see what sort of drainage was going on. Under the couple inches of compost I found hard compaction with plenty of rocks leftover from the construction of our house. All that food I was giving them was probably running off – it just couldn't penetrate to the roots. I fluffed up the soil with more compost, mixed in some acidic food and put the shrubs right back where they were. I am hopeful that in addressing the underlying problem the nutrient issue will right itself. It is good to be reminded to keep the big picture in mind.