Spring vs. Fall planting: Where you stand depends on where you sit

I’m reviewing some literature while working on a proposal and ran across a paper by Lisa Richardson-Calfee, Roger Harris and Jody Fanelli at Virginia Tech on the effects planting date on sugar maple trees.  It’s not actually the topic of the proposal I’m working on but the paper caught my eye because spring versus fall planting is one of those questions that just never seems to go away.  In this particular study, balled-in-burlap trees planted at spring budbreak had more new root growth than trees planted in the fall.  So does this mean spring planting is better? Not necessarily.  For container-grown trees the results were basically a wash.  This is fairly typical.  I’ve not done an exhaustive search but I’ve looked at a fair number of studies of spring versus fall planting and they often show no clear trend or some will show spring coming out better or fall coming out better.

So why do we hear so often that “Fall is a great time to plant trees.”  Well, first off, think about who is saying it. Frequently it is nurseries that are looking to unload inventory that didn’t sell during the growing season or landscapers that are looking to keep crews busy during the slow fall season.  But the other part of whether fall is a good time to plant has to do with rainfall and temperature patterns.  Linda Chalker-Scott is an advocate of fall planting.  And for her location in western Washington – and many other locations in the West – this makes sense.  If we look at average rainfall patterns for Seattle (actually Linda is in Puyallup but no one outside of the Northwest can pronounce Puyallup), planting in October – when the rainy season is getting into full swing – makes much more sense than planting in April or May before the summer dry season.

Rainfall pattern for Seattle, WA Source: weather hannel.com
Rainfall pattern for Seattle, WA Source: weather hannel.com

Where I live in East Lansing, on the hand, our climate has a summer maximum precipitation pattern – as does much of the Midwest.  As I’m fond of telling people, there’s a reason Michigan’s Arbor Day is the last Friday in April. Spring is a great time to plant trees here because soil temps are warming and the rainy season is just getting started.

Rainfall pattern for East Lansing, MI Source: weather hannel.com
Rainfall pattern for East Lansing, MI Source: weather hannel.com

What about fall planting in the Midwest? My take is that fall is an OK time to plant trees but not necessarily the best.  We typically will still have some rain in the fall but temperatures are declining quickly. Our average daily temperature in December is 28 deg. F, meaning our soils are beginning to freeze, while the average December temp in Seattle is a balmy 42 deg. F.  That’s warm enough for Linda’s roots to keep growing – well, actually not Linda’s roots but Linda’s tree’s roots.

In any event, if you live in Midwest and other places with a summer max. precipitation pattern, your state’s Arbor Day is a good guide to plant trees.  If you live out West in areas prone to summer drought then fall may be your best bet.  This is also a another example of why it’s good to get your landscape and garden advice from local sources rather than the ‘one-size-fits-all’ advice common in many magazines and gardening websites.






Richardson-Calfee, L.E, J.R. Harris, and J.K. Fanelli. 2008. Root and Shoot Growth Response of Balled-and-Burlapped and Pot-in-Pot Sugar Maple to Transplanting at Five Phenological Growth Stages J. Environ. Hort. 26(3):171–176.

Up, up, and away…

First, let me cue the 5th Dimension.


I got a call the other day from the owner of a local hot air balloon company.  They specialize in fall color rides and he wanted to include some info from me about the state of fall color in Michigan this year.  Despite our concerns following this summer’s heat and drought, it turns out this year has been very good for fall color.  I think our color has been a bit more variable than usual with some trees turning early and I’m noticing many maples are dropping pretty leaves quickly once they hit peak.  Nevertheless, nature is giving us a great show. And if you’ve got a little extra spending money, there’s probably no better way to see it than from a beautiful balloon…

Photos: Scott Lorenz, Westwind Balloon Co.




Fall for Ornamental Grasses

I’ve written about ornamental grasses previously – they really are one of the toughest, most useful yet under-appreciated groups of garden plants.  Most provide at least three seasons of interest, but fall is when they really shake their pom-poms.

On a recent conference trip to western Michigan with pal and plantsman Paul Westervelt, we stopped by the trials at Walter’s Gardens of Zeeland – one of the largest perennial propagators (wholesale) in the country.

It was a beautiful, breezy day in their extensive gardens, and the grasses were positively alive with light and motion (and kittens – seven or eight, I think). What a fantastic afternoon.

 Here are a few recent introductions that knocked our socks off.  All are hardy to at least USDA Zone 5, heat tolerant to Zone 8 or 9, and the non-natives have been screened for any invasive tendencies. All are patented.

Panicum virgatum ‘Dust Devil’

 There are many great cultivars of our native switchgrass out there; but few come in under 6’ or 7’ – problematic for the small garden. Dust Devil is comparatively  petite – 3 to 4 feet tall, blue-green foliage, and resists the rain beat-down that often happens to the rangy cultivars. Selected by Michigander Gary Trucks.


Pennisetum alopecuroides ‘Burgundy Bunny’

 Paul and I were especially impressed by this sport of ‘Little Bunny’.  I’ve grown tons of ‘Little Bunny’ which is eminently useful for a pouf of “grassiness” at the front of the border.  ‘Burgundy Bunny’ brings terrific color that only gets better in the fall, in the same small package.  From Walla Walla Nursery and introduced by Plant Haven.

Paul models Pennisetum alopecuroides ‘Red Head’

Nothing petite about this monster Fountain Grass.  Wow. 5’ tall and as wide, with gigantic foxtail plumes. As with most Pennisetum species, the show starts mid-summer and continues through fall.  Selected by the perennially prolific Brent Horvath of Intrinsic Perennials.


Schizycharium scoparium Blue Heaven™ (‘MinnBlueA’)


Selected by grass maven Dr. Mary Meyer from her trials at the University of Minnesota.  Mary has found a nice Little Bluestem that has outstanding foliage color (gets even better as the season progresses) and a very upright habit that fights the flop.  Native across much of North America and perfect for awful sites, Little Bluestem laughs at clay, heat, and drought, once established.  

 Andropogon gerardii ‘Indian Warrior’

Little Bluestem’s big brother of the tall grass prairie.  Another upright flop-fighter, this Big Bluestem is from Brent Horvath/Intrinsic. I’ve enjoyed Andropogon in my garden (got it from Paul) – the colors are amazing- but by summer’s end, they’ve flopped all over their neighbors. Can’t wait to give ‘Indian Warrior’ a try.

Lots more info on these and other grasses and perennials at Walters Gardens’ consumer portal www.perennialresource.com


Kittens in the grasses.  Ahn.


Finally: when in Grand Rapids, stop by HopCat for a tremendous selection of Michigan craft beers and hard ciders and the suitably-name Crack Fries (yes!!!). 

Fearless fall color predictions

Happy Labor Day!   Hopefully everyone had an enjoyable 3-day weekend.  Labor day is the unofficial end of summer, which means fall is just around the corner.  In fact, fall may be a little early this year around these parts.  We are already starting to pick up some fall color – mainly maples, sassafras, and sumac.  I usually get some calls from various media outlets asking for predictions on fall color.  It’s always a dicey proposition.  Weather going into fall is certainly a factor for fall color, but conditions during the fall itself are the final trump card.  As I noted, we’re likely to see an early fall here in the Upper Midwest and, if we don’t start getting some decent rain, I suspect it could be a relatively short season as trees begin to drop leaves early due to continuing drought stress.  Of course, all this can change relatively quickly if we get into a different weather pattern.

July 28, 2012. Sumac in fall color near DeWitt, MI.

Speaking of fall leaf color, the Fall Color Guy (aka Dr. Howard Neufeld, Appalachian State Department of Biology) has started his annual reports.  http://biology.appstate.edu/fall-colors .  This site is a great resource if you’re planning on doing some leaf peeping in the Appalachians.  And even if you aren’t, I still recommend this site as one of the best on the biology of leaf color.

Fall color time…

Did you ever know one of those annoying people who always talks about how great everything is back wherever they were from; the kind of folks that make you want to say, “If things were so much better there, why are you here?”  I have to confess I’m one of those people.  No one’s ever actually given me the “If things were so much better there” line, but I’m sure my Michigan friends have been tempted.  I’m warming to things Michigan but I suspect in my heart of hearts I’ll always consider myself a Washingtonian.


That said, there are some ways that Michigan has Washington beat.  We have long, lovely sandy beaches where the water gets warm enough to swim in; which for me means at least 75 deg. F.  Washington has great beaches, of course, but you’ll never see anyone over the age of 12 in the water without a wetsuit – even in August.  We have real thunderstorms spring, summer, fall and occasionally even thundersnow in the winter!  Western Washington is lucky to have two or three bouts of muffled thunder each year.  And we have real fall color thanks to red maples, sugar maples, oaks, sassafras, tulip poplars and others.  Conifers dominate the Northwest and what few large hardwoods there are (big leaf maple, red alder, black cottonwood) drop their leaves inconspicuously without much fanfare.  Vine maples try to make up the difference but usually just add a splash of color here and there.


As with many states with rich fall color, “leaf peeping” or “leaf looking” is a popular fall pastime and many people plan fall getaways to northern Michigan to enjoy the color show.  For someone in a position like mine, that means calls from media, AAA, and others asking for predictions on whether we’ll have good fall color.  Of course it’s difficult to predict since conditions during fall itself (i.e., sunny days and cool nights) are among the biggest determinants.  We do know that drought conditions late in the summer can result in early leaf drop or limit production of some secondary pigments, resulting in a shorter and more muted display.  For us in Michigan that suggests a below average fall color show up North since many counties have received 50% or less of their normal rainfall since July.


For those interested in learning more about fall color, I high recommend ‘The Fall Color Guy’ website http://biology.appstate.edu/fall-colors The site is maintained by Dr. Howie Neufeld, Professor of Plant Physiology at Appalachian State University.  Howie and I crossed paths at the University of Georgia when he was a visiting scientist and I was a Ph.D. student.  He provides some of the best information I’ve seen on the science of leaf color and his essays on the website are good reads.

Pssst…over here…trees got nothing on us…

We usually look up to the trees for the spectacle of fall foliage color but there’s plenty happening down low.  Ornamental grasses in autumn are, of course, amazing – I think I’ll give them a post of their own.  But there are a few perennials that consistently deliver good fall color instead of turning to brown, crunchy paper.

For the shade to part-shade garden, Polygonatum odoratumthen ‘Variegatum’ is a plant for three seasons. Arching stems
spring forth in, well, Spring, with fresh green and white variegated
foliage. Pairs of little creamy bell-like flowers dangle from each leaf
node.  The foliage looks terrific all summer long, and
you get a shot of golden yellow for fall.

More reliable than a tulip poplar!  Newport, VA, October 10.

I know I’ve mentioned Amsonia hubrichtii in some past posts, but I just can’t help it.  Finally, finally named “Perennial Plant of the Year ” for 2011 by the Perennial Plant Association.  Not sure what took so long.  Exhibits the best boofy habit of all perennials (somewhat like “floofy”, but rounder).  Native to southern/central U.S. and totally drought tolerant.  The pale blue star-shaped flowers in late Spring are fairly underwhelming, especially given all the other stuff going on at the time. The fine, needle-like foliage adds a wonderful soft texture throughout the summer.  As the days shorten and the nights cool down, it begins to glow…first a soft gold, and then adds bronze and apricot to the mix – basically a color twin of Sporobolis heterolepis (Prairie Dropseed, previously described in a GP post).

The first flush of gold, just getting going in our garden last week…

In full glory. Late fall at Chanticleer (Radnor, PA).

Some cultivars of Hosta, such as ‘Sum & Substance’,  reliably produce gold fall color, as do some ferns.  Any others you’d like to add to list?

Is Fall Really a Great Time to Plant Trees?

One of the joys of working on a university campus is that construction never seems to end.  As near as I can tell there are about 3,000 orange construction barrels that permanently reside on the MSU campus that simply get shuffled from one end of campus to the other every few months.  Along with all the construction comes a never ending series of new landscape projects.  Driving by one of the most recent projects the other day got me to thinking about the myth of Fall planting.  In numerous extension bulletins and certainly in nursery sales advertising we hear that “fall is the perfect time to plant trees”.

Photo: Dana Ellison

The recent fall planting job on our campus gave me pause to think about this.  I haven’t had a chance to completely survey the carnage but I suspect about a third of the trees will need to be replaced.  Obviously there are lots of things that may have gone wrong here, irrespective of when the trees were planted and one exception doesn’t prove the rule.  Nevertheless when I look back on the planting disasters I’ve been called in to inspect over the years a disproportional share (I’d say by a factor of two or three to one) are fall planting jobs.


What gives?  Well, the notion that fall is a great time for planting is built in a faulty premise, at least for this part of the country.  Probably the most commonly cited reason for fall planting is that trees grow a lot of roots in the fall.  This assumes that since there’s no shoot growth occurring, trees automatically shift reserves below-ground.   There is certainly a ‘pecking order’ of carbohydrate distribution within a tree based on relatively strengths of sources and sinks.  But there’s one factor that trumps all others: temperature.  Soil temperature is the biggest driver of root growth.  Measurements of new root growth in a cottonwood plantation in Wisconsin provide a classic example.  As temperatures decline in the fall, new root growth essentially ceases.  For trees that are well established, this is no problem.  For trees that have just been transplanted and need to re-establish root-soil contact this is a tough row to hoe.  Throw in a tough Michigan or Wisconsin winter and the tree’s facing an uphill climb.


New root growth of eastern cottonwood (top) and soil temperature (bottom). Source: Kern et al. 2004. Tree Phys. 24:651-660.

Again, most planting failures have multiple causal factors.  Even if the trees on this site had been planted in the spring, they may have still experienced problems.  My point is that a more accurate statement is “Fall is an OK time to plant trees”; not the ‘best’ time or even a ‘great’ time.  I think these statements are often driven by the fact the fall is a slow time for nurseries and landscapers.  When homeowners or landscapers ask me about fall planting the first thing I ask is if there is any reason why they can’t wait until spring, the real ‘best’ time for planting.