If you thought spring was the best season for planting, you’re not alone. However, there are so many good reasons to plant shrubs, trees, and perennials in fall instead. Our FAQ covers everything you need to know about what, where, and when to plant in fall.
1. Can I really plant in fall?
Yes! Fall is a fantastic time for planting shrubs, trees, and perennials because the cooler temperatures and shorter days mean less water stress for the plant, and that means less work for you in terms of watering and monitoring your new plants.
2. What makes fall good for planting?
Root development is critical to getting new plants established, and fall weather creates optimum conditions for roots to grow. Since root growth continues until temperatures fall into the low 40s (~5.5°C), that means several weeks, perhaps months, of stress-free conditions for this crucial establishment – the sooner a plant gets established, the sooner it will perform as you see in photos. It’s the perfect way to get a head start on a better landscape for the following season and beyond.
3. Is there anything that shouldn’t be planted in fall?
Fall is ideal for planting almost anything, but there are a few scenarios to avoid, depending on your climate:
– Any plant that isn’t reliably hardy in your area. Exploring a plant’s hardiness potential is one of the most fun and rewarding parts of gardening, however, these types of experiments are best begun in spring, so plants have the longest possible exposure to warm weather to grow the roots they will need to even have a chance of making it through winter.
– Similarly, if a plant typically experiences a lot of damage or dieback over winter in your area, like butterfly bush, bigleaf hydrangeas, or crapemyrtle, it is best spring-planted as well.
– Evergreens, and especially broadleaf evergreens like boxwood, rhododendron, and holly, are best spring-planted in cold climates (USDA zone 6/7 and colder). These plants lose water through their foliage all winter due to sun and wind, but cannot replace it when the ground is frozen. As such, it’s best to give them the longest possible window to get established before winter’s stressors begin. Conifers, especially needle-leafed types like pines, are slightly less susceptible to this issue than broadleaf evergreens, but we’d still advise that cold climate gardeners stick to spring planting for the best results.
4. How late is too late for fall planting?
If you live in a cold climate, you want to have your new plants in the ground at least six weeks before the ground freezes – not first frost or freeze, but before the ground freezes. That’s a tricky date to gauge, as it can vary so much from season to season, so a general guideline, those in USDA zones 2-6 should plan to finish up fall planting by mid-late October, zone 7 by mid-November, and zones 8 and warmer can plant well into December, depending on conditions. Root growth will essentially cease once the ground is frozen, so that six week window provides an opportunity for some establishment. If you scoop up some super late season bargains, or still have unplanted shrubs, it’s always best to plant them than to try to overwinter them in their containers, even if it’s very close to winter.
5. Is there anything special I need to know about preparing the planting site?
No – in terms of digging the hole and actually installing the plant, the process is the same no matter what time of year you plant. Here’s a quick how-to video.
6. Do I still need to water plants that were fall-planted?
Yes. Water well immediately after planting, and monitor watering needs for the next several weeks. Plants are unlikely to need as much water as they would if spring-planted, however, this will depend entirely on the weather you are experiencing. If it is unusually hot and dry, more water will be required. Check water up until the ground freezes, if that occurs in your area – you may need to water even into late November if rainfall is scarce. If you are not confident in your ability to gauge a plant’s water needs, consider purchasing an inexpensive moisture meter.
7. Should I mulch my new plantings?
Absolutely, yes! A good 2-3”/5-7cm layer of shredded bark mulch provides even more ideal conditions for root growth, as well as an extra layer of protection for impending cold. We recommend maintaining this mulch layer all year round.
8. What about fertilizing?
There should be no need to provide any fertilizer for plants installed in autumn. They will have been amply fertilized by the grower or garden center prior to your purchase. Plus, as the plant is already heading toward seasonal dormancy, there’s no need to apply a bunch of fertilizer it cannot use. You may wish to apply a fertilizer the following late winter/early spring; that can be applied monthly through late July if desired. We recommend a granular (not liquid) fertilizer formulated for woody plants, like a rose fertilizer.
9. Should I prune my new plants?
It depends on the variety, as well as your intent for the plant. Generally speaking, though, newer plants need little if any pruning, and any pruning you do should be properly timed according to its bloom time. As with all pruning, when in doubt, don’t prune – you can contact us for some advice, or reach out to your local cooperative extension for expert advice for your area.