Fall is for planting
Garden clippings for Oct 15, 2022
Every fall, Landscape Ontario, the horticulture industry’s primary trade association, touts “Fall is for Planting” as a tag line in all its communications. Their aim is to compel the gardening public that fall is the preferred time to plant anything. Anything, except spring annuals.
It’s a tough sell. Spring is when gardeners get their adrenaline moving. After a cold winter, folks just want to dig holes, plant veggies, and pull weeds.
Truth be told, fall is a better time to plant than spring. Cool temperatures, shorter day length, and dependable rainfall are ingredients that make plants happy. Planting in autumn gives up to three months for plants to grow roots and become established before freeze-up. In spring they will hit the ground running.
Spring 2022 is case in point. If I planted a tree on Victoria Day weekend, all would be well. The weather was cool with rain on Monday. But a week later it was dry, followed by more stressful heat and draught in June, July and August. Summer 2022 was not a banner year for spring planted trees. But if I would have planted the same tree in fall of 2019, it would have had several cool months to generate roots and prepare for spring growth.
For most trees, shrubs and evergreens, it is safe to plant up to 4 weeks before ground freezes. For Sarnia Lambton, bare soil does not usually freeze until mid to late December. Where soil is covered with mulch or thick grass, it may not freeze until early January.
The date that ground freezes will vary from year to year. Sandy soil freezes deeper and quicker than clayey soil. A blanket of insulating snow may prevent soil from freezing until that snow disappears.
When planting in fall, be sure to water well after the job is done. I suggest setting the hose at the base of the plant and allowing it to trickle for 15 to 30 minutes. The initial watering is important to give plants moisture but also to eliminate air pockets that may have resulted from transplanting.
Use a root booster fertilizer at planting time to give extra insurance. Mixing compost, manure or triple mix with the existing soil will pay off with better growth.
Mulch is your friend. A 3- to 4-inch-thick layer of shredded wood mulch will provide insulation to the soil below, thus postponing the freeze-up date. Mulch will improve soil texture and will help retain soil moisture.
There are a few exceptions to fall planting. If planting in late fall, say, after November 15, certain evergreens may not have enough moisture reserve in their needles to withstand sunny, winter wind. I have seen Holly, Pines and Rhododendron suffer when planted late, in exposed conditions. Ornamental grasses are another plant group that would rather not be planted after November 15.
Softwood trees such as Willow, Poplar and Silver Maple may also suffer from late digging, particularly if they are dug up and planted with their roots exposed. Nursery grown trees that are potted and already grown in a container or root ball will have no concerns with fall planting.
Have fun with fall planting. You and your trees will be glad you did.
