September Tasks & Tips for the Ornamental Garden

September Tasks & Tips for the Ornamental Garden

  • By Cathy Caldwell
  • /
  • September 2019-Vol.5, No.9
  • /

Japanese stiltgrass. Photo: NY State IPM Program, Cornell University

Is anybody out there as tired of pulling stiltgrass as I am?  At least it’s easy to pull, and that seems to be its only saving grace.  If you have some in your beds and it has not yet flowered and dropped seeds, I suggest you rush out and pull it while you still can.  Check out the stiltgrass alert that’s currently appearing on the home page of Blue Ridge PRISM (Partnership for Regional Invasive Species Management),


Having spent the second half of August dealing with stiltgrass (the price you pay for a long vacation, apparently), I’m eager to turn to the fun tasks of fall.  Fall is one of the best planting seasons, so get ready.  It’s especially good for planting shrubs and trees, though if it’s still hot, delay for a week or two until weather is cooler.  The ideal time is when the leaves begin to change color.  For expert, detailed advice on planting trees, consult “Planting Trees,” Va.Coop.Ext.,

Water newly-planted trees and shrubs regularly throughout the fall.  Check the soil near the roots once a week.  If the soil near the trunk is dry, the tree needs water, and plenty of it, especially if there’s been no rain.  If the soil near the trunk is moist, don’t over-water as that can kill a tree as surely as under-watering.

September is an excellent time to start dividing those perennials that need it, and the ideal time — adjusted somewhat for climate change — appears to be around the 2nd or 3rd week of September. “Dividing Perennials,”

Fall is also the time to divide bulbs and plant new ones.  This can be done anytime until the ground freezes.

Fertilize bulbs:  Any time after your bulbs have finished blooming is a good time to fertilize them, but they may not need fertilizer if you regularly add organic matter, like compost, to your beds.  But if your narcissus and other spring-blooming bulbs look like they’re not getting enough nutrients from the soil, you might consider fertilizing them lightly with a 5-10-10 fertilizer.  Avoid high-nitrogen fertilizer (the N element, the first of the three numbers listed on the label).

For more detailed tips, see previous September issues of The Garden Shed:   2018, 2017,  2016 and 2015.

Happy gardening!



Month-by-Month Gardening in the Mid-Atlantic, (Viette, 2004)

“September Tips:  Lawns and Landscaping,” Va.Coop.Ext.,

Frost Dates,

“Dividing Perennials,”

“Perennials: Culture, Maintenance and Propagation,”

“The Ornamental Garden in September, 2015,”

“The Ornamental Garden in September, 2016,”

“The Ornamental Garden in September, 2017,”


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