Don’t Overlook These Garden Winterizing Tasks

Don't Overlook These Garden Winterizing Tasks

It’s hard to overlook: raking leaves, chucking frost-dead annuals, planting spring-flowering bulbs, cutting back fall-ravaged perennials, etc. We all have a fall garden punch list. Have you included any of the following tasks on yours?


Great lawns flourish with two fall fertilizer applications. I like to use holidays as reminders. The first should be done around Labor Day, the second around Halloween. Notice italics. If you don’t get the last app down by Halloween it doesn’t mean you shouldn’t do it. The first weeks of November are still fine to fertilize lawns. Just make it happen and reap the rewards come spring!

If fall rains have been miserly, continue supplemental watering on a regular basis until the ground freezes. Prioritize: newly planted evergreens (pay particular attention to arborvitae, boxwood, holly, rhododendrons and hemlock) in sunny, windswept northwest and southwest-facing sites, or plants against structures with wide rain-deflecting overhangs.

It’s only too late to plant bulbs when you can’t get the shovel in the ground. That being said, know that tulips are more tolerant of late(r) planting than daffodils. Daffs, bulbous perennial workhorses that they are, appreciate the courtesy of having extra weeks to form roots before soil freezes. Always: fertilize and water new bulb plantings to welcome them and jumpstart rooting. It’s a keen idea to mulch bulb beds after the ground freezes. Makes for later, but more consistent (and often larger) flowers.

Harvest tender bulbs for indoor winter storage no later than the first frost that blackens and kills foliage. Some of the major candidates for that procedure would be: dahlias, cannas, gladiolus and tuberous begonias.


Consider applying gypsum to parkway, lawn and garden bed soil exposed to salt spray from traffic. Salt is insidious as it can damage two ways: burning/killing evergreen foliage on contact and soaking into soil, then burning roots. Did you know that salt can be sprayed more than 100’ from a roadway? That’s why you see so many burlap (or tarp) screens erected on the street side of evergreen plantings along roadways. Preventative applications of gypsum may help neutralize the damage from salt assault.

Snow is great plant protection as it insulates from wild swings in winter temperatures. In years with sub-zero temperatures, no snow cover and lots of sun with drying winds evergreen ground covers can take it on the chin. In Chicago, we see it most devastatingly on English ivy and occasionally Pachysandra. Laying evergreen boughs over these exposed beds can make a huge difference in the spring body count. What a great way to recycle a spent Christmas tree!


Consider applying tree wrap to smooth-barked trees that are potentially subject to sunscald/frost crack. Prime candidates would include young: ‘Autumn Blaze’ maple, crabapple, cherry, and linden. Caution: Don’t apply before plants are dormant and only when bark is perfectly dry. Never wrap wet tree trunks.

Many of the new “hardy” mophead Hydrangea (H. macrophylla) cultivars are reliably stem-hardy, but not flower-bud-hardy. That means after a cold winter, the plant stems may be killed to the ground, but the crown will be alive to regrow. That often comes at the expense of flowers in the coming year. Creating cylinders of hardware cloth around these plants and filling with 15” or more of medium chunk bark may be just the protection the horticulturist ordered.


Drain hoses before storing. Whether it’s a pot, fountain or birdbath empty anything: concrete, terra cotta and glazed that might freeze from holding frozen water or soil over the winter, then store.


Tony Fulmer
Chief Horticulture Officer