Determining Fall Planting Dates

When rainfall and temperatures begin to moderate at the end of summer, it’s time to start thinking about fall planting. Fall is a good time to plant many different kinds of trees and shrubs and even perennials. Fall-planted specimens often settle into their new homes more easily than those planted in spring, because they usually don’t have to contend with a period of hot, dry weather the way the latter do.

Garden shovelsTiming of fall planting has much to do with soil temperature. Many plants can grow roots when the earth is as cool as 45˚F. At planting time, the soil temperature at 6 inches deep should be about 55˚F to give plants ample time to start getting established. Conifers prefer a soil temperature closer to 65˚F, so they should be planted in earliest fall.

In general, finish your fall planting about 6 weeks before your first expected frost date (8 weeks for evergreens). In Zones 3 and 4, you would count back from the latter half of September. Zones 5 and 6, your first frost will likely occur by mid-October.

In warmer zones where the ground doesn’t freeze solid, plant when the hottest, driest weather is behind you and the rainy season is beginning—usually October or November.

More tips for fall planting:

  • Choose healthy-looking plants at the nursery
  • Choose balled-and-burlapped or container-grown plants, not bare-root plants
  • Make sure the plant receives ample water (about an inch a week, from rain and/or irrigation) at planting time up until the ground is frozen (if applicable)
  • Avoid species that are generally slow to establish, such as magnolia trees, birch, willows, hemlock, oak and hornbeam

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2 thoughts on “Determining Fall Planting Dates

  1. Thank you for addressing the topic! I hope you will incorporate this temperature information into a much larger article on the intricacies of fall planting. I think fall planting is overlooked by a lot of the gardening public and almost all of the non gardeners. It’s enormously beneficial in many cases, but not a good idea in others and I have yet to see a publication that addresses the topic comprehensively.

    Many gardeners look to this publication as a resource so I hope you’ll lead the discussion…someone needs to.

  2. I garden in zone 5B and my average first frost date is October 8. If I finished my fall planting 6 weeks before my first frost date, as this article suggests, I would need to finish about the third week of August when it is still pretty hot. I like to finish my fall planting by September 10, about a month before the first frost. I know everyone’s micro-climate is different, but I just thought I would point out that a lot of Zone 5 gardeners really need to finish fall planting well before October, but they may not be able to start a full 6 weeks before the first frost due to hot August weather.

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