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September's gardening tasks all about dividing and conquering

Master gardener John Hethrington says fall is the ideal time to trim and divide your perennials — and share with your neighbours
John Hethrington is a master gardener who shares monthly gardening tips with Village Media readers.

Divide and conquer in your gardens this month with John Hethrington's September to-do list. 

  • Trim back perennials like daylilies and iris. Divide them as needed. Make sure it is a cool, cloudy day to divide and replant, or pot up for your neighbours or fall plant exchanges. 
  • Fall is the ideal time to divide and plant iris, daylilies, peonies and many other perennials. Share extra plants with neighbours.
  • Buy and plant spring flowering bulbs. Your efforts will be rewarded next spring. Check out Botanu online at
  • Add a little bonemeal fertilizer or special bulb food to the bottom of the planting hole. Water well after planting to start root growth.
  • Take a critical look at your garden. Then fill in any gaps that may have developed with new perennials, shrubs and/or evergreens. They will get a huge head start over plants planted next spring.
  • Bring in house plants when the evenings start to cool down. First, give them a thorough spray with insecticidal soap so that there are no unwanted hitchhikers coming into your home.
  • With cool nights and hoped for fall rains, it’s the ideal time for lawn repair. Dig out weeds, add clean, weed-free topsoil and re-seed. Water as required 
  • Fertilize lawns with root-building “fall fertilizer” with a low first number (nitrogen) and a high third number (potash).
  • Don’t use the lawn fertilizer you have leftover from the spring, probably with a high first number (nitrogen). Save it for early next spring.
  • It’s been, first, a dry summer and then lots of rain, so water perennials, shrubs, evergreens and trees deeply. Dig a little test hole, say 14”-16” deep. Check moisture levels at that depth. If the bottom of the hole is dry, water weekly until frost.

John Hethrington spent his early life gardening in Toronto and earned his certification as a master gardener before moving to Meaford where he cultivates 2.5 acres with 20 different gardens.