By Kerry Ann Mendez
A proper "good night" to your flower gardens before the onset of winter will pay huge dividends. Below are some practical steps for enjoying a healthier, flower-packed garden next year.
Wait until mid to late October to prune many perennials to within inches of the ground and then place the cuttings in the compost pile.
Some perennials that SHOULD be cut back are Iris, Peony, Daylilies, Hosta, Phlox (Phlox paniculata) and any plants that are diseased or insect-infested (but don't put the foliage with disease or insect issues in the compost pile).
For winter interest leave perennials with interesting form, structure and/or seedheads. Nature's winter birdfeeders include Coneflowers (Echinacea), Black-Eyed Susan (Rudbeckia), Sea Holly (Eryngium), many ornamental grasses, Sedum and Joy Pye Weed (Eupatorium purpureum). Perennials that are either evergreen or semi-evergreen should be left untouched: Lenten Rose (Helleborus), Coral Bells (Heuchera), Foamflower (Tiarella), Foamy Bells (Heucherella), Candytuft (Iberis) and Dianthus.
Some perennials overwinter BETTER if pruned in the spring and not the fall. These include those with woody stems: Russian Sage (Pervoskia), Lavender, Montauk Daisy (Nipponanthemum nipponicum), Hibiscus and Butterfly Bush (Buddleia). Others that are also best cut back in spring include: Hyssop (Agastache), Wandflower (Gaura) and Red Hot Poker (Kniphofia). You can also leave any natives alone until spring - they can provide safe harbors in winter for pollinators' eggs, pupae or caterpillars.
Even though the topgrowth of perennials and many flowering shrubs is dying back, their roots are still growing (soil temperature stays warmer than air temperature). Water gardens deeply (one inch of water) once a week if there has been no soaking rain. Continue until the ground starts to freeze (typically late November).
If your soil is lacking in nutrients and/or has poor structure (i.e., sandy or heavy clay), shovel several inches of enriching mulch around perennials and shrubs. This will break down over winter and benefit emerging plants in spring.
One final weed-eliminating sweep will save a lot of headaches next spring. Many pesky weeds are perennial, so removing them now means one less weed (and their seeds) next year.
Now is the time to do a soil pH test (or better yet a complete soil analysis) if you have not done this in three or more years (or have never tested your soil!) You can either do it yourself with a product like Rapitest, or send a soil sample to the University of Maine's Extension Office. Estabrook's has soil testing products as well as soil sample mailing kits. If a soil correction is needed, taking the necessary steps in fall will jump-start next spring's bounty.
As noted above, in fall the soil temperature remains warmer than dropping air temperatures. This, coupled with typically increased rainfall, reduces transplant shock and promotes root development. Fall is a terrific time to plant perennials, flowering shrubs, evergreens and trees that are slowly going dormant. Take advantage of our fall sales to beautify your landscape!