Gardening in Fall

In Fall, Feature, Gardening, News, Perennials, Tonkadale Greenhouse, Trees and shrubs, Winterby Megan Nichols

They’re here! The sunny (but not sweltering) days and cool (but not freezing) nights that we love so much have finally arrived. This is THE BEST gardening weather! So, is it still OK to plant? Sure it is, and BONUS: it’s Customer Appreciation Days Saturday, September 7th and Sunday, September 8th! That means ALL perennials, trees, and shrubs are 50% off.

For your best gardens ever, here are some tips and tricks to give your perennials, trees, shrubs, and lawn their best chance at being beautiful specimens this season and next. After all, 2020 starts now!

Trees and Shrubs

For existing trees and shrubs, especially those that have been planted just this year, be sure to keep watering. Fall can be a dry time of year, and is often still sunny and warm, all of which can dry out the soil and roots. This can be especially detrimental to evergreens, which need to take up all the moisture they will carry in their needles through the winter to combat drying winter sun and winds. In the absence of rain, water one inch per week.

Fall is the best time to plant deciduous trees and shrubs. Evergreens can still be planted, but the sooner the better. Why is it such a good time? There’s still time for roots to become established even as the plant begins to go dormant, and the cooler weather causes less stress. In spring, the tree or shrub will reap all the benefits of being in the ground as it starts to wake up, such as the snow thaw and rain.


Cooler weather is good planting time for perennials, too. (It’s hard enough adjusting to a new home without it being boiling hot!) There is still plenty of time for new roots to get off to a good start. For best results, here are tips for fall planting success:

Dig hole 2x the diameter of the pot, and as deep as the root ball
Add Espoma Bio-tone and back-fill hole with 1/3 to 1/2 compost and 2/3 to 1/2 original soil
Water well until the ground is frozen (1 inch per week)
Cover plantings with straw or marsh hay after the ground freezes

Dig and Divide
Wondering when to divide and replant peonies and iris? The cool weather of fall is perfect, and now is the right time for these plants.

In the Lawn

Now is the time to plant grass seed! Before mid-September is best, but a little beyond is okay, too.

Bonus: Now is the best time for weed control, too! Plants are greedily taking in nutrients in order to overwinter, so weeds like Creeping Charlie quickly absorb herbicide, too, making the solution that much more effective. We recommend Bonide’s Weed Beater Ultra for myriad different weeds, and Bonides Stump Out Stump and Vine Killer for Buckthorn.

Winter Over Plants
Any plant has a better chance with some winter protection, but fall-planted perennials really benefit from extra help.

So what’s the deal? Usually there is adequate snow cover and temperatures stay cold throughout the winter. Last winter is a good example of the unpredictability of Minnesota weather, though. Unseasonably warm temps are fine if we have snow cover, which acts as a natural mulch. Same goes for a deep freeze, as long as there is snow it’s fine. Without snow, the ground can go through a freeze-thaw cycle that can kill newly planted roots that haven’t had a chance to get established. Last winter caused plant death even in well-established, supremely hardy plants (Hosta! That almost never happens).

What do you do? Wait until the ground freezes solid. Then cover perennials with straw, marsh hay, or fallen leaves. Remove the covering in spring once night time temps show above freezing for at least 10 days.

Before covering needs to happen, though, the beauty of the garden may become questionable. So, to cut or not to cut plant back?

Consider “not,” and leave plants that provide winter interest or something of value to the birds. Stalks of plants and stems of shrubs can provide shelter. Plant such as Coneflowers, Black-eyed Susan’s, and Asters provide food for birds. Mounding and bunching grasses can provide overwintering sites in bare soil under the blades. Tall grass blades left uncut provide winter interest for us humans, too, and snow collecting on seed heads and browned hydrangeas blooms is quite attractive.

Remember to keep enjoying your gardens all through fall and winter, even as you plan for spring!