Susan Harris
All about gardening the eco-friendly way, by Susan Harris and 22 other garden writers and experts.

Arbor Day – BAD for planting. Earth Day? Same deal.

January 31, 2008 · 4 comments

With spring fast approaching, let’s look at  two popular plant-related spring events, especially at what one prominent authority on sustainable gardening has to say about them.   She’s horticulturist Linda Chalker-Scott with Washington State University and her website features "Horticultural Myths."  There happens to be one of those on point, from 2001:

The Myth of Arbor Day/Earth Day Planting in the West: "Arbor Day/Earth Day is an ideal time to install trees."

According to the good professor, Arbor Day began in Nebraska back in 1872 as a way to encourage the planting of trees on what was basically grassland, and the official date was set for the first Friday of April.  She applauds the moves taken here in the East to move the date up in the hotter regions and back for the colder, for obvious reasons.

Earth Day, officially April 22, is more recent but still, notice, in the spring, and has been used as an event for "revegetating human-altered landscapes," including the planting of trees, which she thinks that’s a bad idea - in the West.  In the West they average from 2 to 10 inches of rain per month through the summer, with Seattle at the 2-inch level.  Besides the problem that plants need more water during the heat of summer, late spring and summer are when they’re devoting all their resources to new above-ground growth and can’t develop the kind of root structure necessary to survive in the long run. 

What Will Survive?

According to Chalker-Scott, the only plants that can survive dry summers are: well established native or Mediterranean climate plants grown under optimal conditions.  Notice the plants not ONLY have to be naturally drought-tolerant but they have to be grown under their ideal conditions and have already survived a year or two.  And how many of our suburban and urban gardens offer optimal conditions?  Thanks to the nature of development itself, very few.  So what chance does a sapling stuck in the ground in April have, especially in the hell strip between the street and the sidewalk -  a less than tree-friendly place if there ever was one.

Back East    

So what’s the situation here in the supposedly wet East?  Not so different, as it turns out.  Our average rainfall (in DC) is only about 4 inches per month for the summer months but man, those wet days may be over.  In 2007 we averaged about half that per month, but it’s even worse than that sounds.  Because so so much of that rainfall occurred during downpours, droughts were longer than the 2-inch number would indicate.  With our less-than-normal rainwater coming in more extreme amounts – either none or too much at once – it was a terrible situation for not just plants but also runoff into our waterways.  Hello, Global Weirding.

All this explains why the city garden manager in my town spends Earth Day and Arbor Day FUMING about the utter waste of saplings.  Move it to fall, he says to anyone who will listen.  It’s happening in enlightened communities across the country and sounds like a change whose time has come.

But What About Those Fun Spring Events?

But-but-but spring is when HUMANS are ready to start planting.  People are in the MOOD.  That is, if they ever are, and let’s face it – most people never are.  But in my town anybody who gives a damn about trees and the environment in general turns out in droves for both events.  They’re So happy about the new trees the city gives away on Arbor Day.  But I’ve seen the results by late summer and I don’t know who I feel sorrier for – the trees or the discouraged treehuggers, who see their efforts come to nothing, year after year.  Some succeed, I’m sure, but they’gardeners, not your average homeowner, tree-lovers though they may be.

Ann Whitted –


1 Linda Chalker-Scott February 1, 2008 at 7:33 pm

Thanks for bringing my web topic to the gardening masses! I agree, it is tough not to succumb to planting in the spring. And if you’re doing your own landscape, you can devote the extra water to them in the summer. But here are a couple of the strategies I use for my own place as well as others:
1) Have Arbor Day/Earth Day be a Tree Care Day – spend the time spreading good organic mulch. This will prepare your landscape for the dry summer months, as well as helping to suppress weeds. (I have just published a literature review on landscape mulches in the December 2007 issue of the Journal of Environmental Horticulture. Email me for a free pdf copy!) Other good activities: removing invasive plants, planting flowering annuals in containers or borders, putting in bulbs, tubers, etc.
2) Go ahead, buy those wonderful blooming shrubs and trees – just don’t install them yet. Move them around your landscape during the spring and summer to figure out where you like them the best. Keep them well watered – and in the fall, you’re ready to install them.

2 Kathy February 9, 2008 at 4:14 pm

Hmmm, maybe we can re-educate folks to spen Arbor Day making their existing trees healthier – or caring for those in nearby parks by removing invasive vines off them, fertilizing, pruning dead limbs, etc.
Earth Day can be more about food and sustainable gardening and get off the tree topic. Give out packs of veggie and herb seeds or native flowers instead of sickly saplings.

3 Ginny Stibolt February 15, 2008 at 11:31 am

Actually late spring is a good time for planting in Florida where our wet season starts in June. We normally have twice as much rain during our 5 wet months as in our 7 dry months. Of course, there are no guarantees on that rainfall, but still if you take the averages, the wet season is the best bet. For dormant, deciduous trees in northern and central Florida though, early winter is the best time to plant and Florida’s (and Louisiana’s) Arbor Day is the 3rd Friday in January. This is pretty much the equivalent of fall in temperate climates like the Mid-Atlantic.

4 jodi February 19, 2008 at 11:32 pm

I missed this post somehow–was too busy reading feeds via Blotanical instead of my usual feed reader, I guess. We don’t have Arbor Day (and if we did we’d spell it Arbour, of course…) but there is some fuss around Earth day and planting trees. But that’s where our climate differs so radically from yours; being a maritime climate in the Maritime provinces, we don’t experience droughts as such; maybe a dry spell sometimes in late July or August, but nothing like what more southerly parts of the continent (including parts of more western provinces) endure. So we CAN plant trees and shrubs all through the growing season. It’s being an effort, however, to encourage people to keep ON planting past mid July–be it annuals, perennials, shrubs or trees. They’re learning, but slowly.

Previous post:

Next post: