Native Combinations: 2 for the Shade

Solidago flexicaulis (Zigzag Solidago) blooms on the side of the road in Vermont.  Image by Thomas Rainer

A shade tolerant Solidago?  A few years ago, I saw a beautiful clump of Solidago flexicaulis (Zigzag Goldenrod) on the side of the road in Vermont.  It was so stunning I stopped the car and pulled out the camera (my wife loves it when I do this—our vacation pictures have more plants in them than people).  Initially, I could not identify the flower.  The plant’s broad-leaves have sharply serrated edges.  That foliage combined with the glowing-yellow racemes reminded me immediately of the ornamental perennial, Ligulara ‘The Rocket’.  Was this some kind of native Ligularia I did not know?

To Dig or Not to Dig: Are 'No-Dig' Planting Methods for Real?

photo by Jim Richardson, National Geographic

One recent garden trend that is spreading with inexorable speed is the “no-dig” or “no-till” method of planting.  The basic idea is that plants are installed directly into the ground without tilling or turning over the soil.  While this method is centuries old, it challenges conventional gardening practices of tilling and breaking in the soil before one plants.

I’ve been aware of this method for a while, but have been surprised by how quickly it has become dogma, particularly within sustainable landscape circles.  When teaching a class on soil preparation, I mentioned tilling and watched as many of the students recoiled in protest.  “Isn’t tilling bad?” one student immediately asked.  I was taken aback.  ‘No-dig’ is not just an idea, but a doctrine, a creed, a badge of one’s eco-credentials. Proponents spread the message with revolutionary fervor. 

So is it time to put your tiller on Craigslist?  Let me weigh in on this complex issue and hopefully provide some clarity.  The gardening world has more than its fair share of old wives tales and superstitions.  This is particularly true with anything regarding soil.  We understand so little about what goes on in the soil, yet we dig, till, fertilize, and amend it with reckless zeal.  When it comes to soil cultivation, what’s true?

Here’s the bottom line: ‘no-dig’ is great, but not when the soil is severely compacted. 

After going through quite a bit of research, the evidence certainly favors the ‘no-dig’ approach.  Part of me really wanted to find flaws with this method; after all, breaking the soil before planting just feels so natural, so downright human.  Egyptian paintings 1200 years bc show people plowing fields.  But the evidence generally supports the wisdom of not digging.  Why? 

The New Azalea Garden at The New York Botanical Garden

photo by Angel Franco/The New York Times

This week The New York Times wrote a glowing review of the newly renovated Azalea Garden at The New York Botanical Garden.  I worked on the design for that garden while at Oehme, van Sweden and Associates. 
The assignment was one of the most complex planting projects I’ve worked on.  The New York Botanical Garden was in the process of redesigning the eleven-acre azalea gardens in house, but they hired OvS to design a complete palette of herbaceous plantings to compliment the sprawling shrub garden. 

The challenge was to provide seasonal spectacle throughout the year, not just around Mother’s Day when the garden attracts thousands of visitors.  Designing a perennial garden with year-round spectacle is hard enough; but doing it in deep shade and underneath and around 3,500 azaleas was an especially daunting task.  How do you plant around, under, and next to so many azaleas?  And how do you use perennials to blend and soften the jarring bubble-gum pinks, corals, oranges, and fuchsias of the azaleas?