Tuesday, June 17, 2008

No bare soil: the secret is underplanting

Under our walnut tree: a few gaps that need more hosta divisions

One of the great secrets of outstanding gardens is underplanting. The idea is to plant layers of plants like nature does in a forest. For example, using smaller plants such as ferns, hosta, or perennial geraniums under the canopy of a tree or group of large shrubs.

My picture shows our big walnut tree behind the house. The space under it is a steep slope that used to be covered with weedy lawn grass that was dangerous to mow. (I almost overturned my big Toro mower there a couple of times.)

To start the garden on the slope, we killed off the grass one summer, and then began planting shrubs and perennials that are walnut-tolerant - mostly viburnum shrubs, daylilies, hosta divisions from the shade garden, Solomon's seal (the plain green version and the variegated one), and sweet woodruff, also moved from the shade garden. For early spring, there are tulips, daffodils and grape hyacinths. The area is coming along nicely, but I still have some gaps to fill.

For more planting inspiration, Margaret Roach (garden writer and former editor of Martha Stewart Living) has a great post with lovely pictures all about underplanting. Her blog, which has only been around since March, has become one of my almost daily must-reads. As a gardener, she's a true artist.

© Yvonne Cunnington, Country Gardener


  1. Yvonne-
    I had just come from Margaret Roach's blog reading her post on underplanting to yours, and almost thought that my browser had not made the leap! Too funny that you both have posts about underplantings. Like you, I read A way to garden daily.
    So, you planted under a walnut tree huh! Last to leaf, first to drop, messy fruit with a natural plant poison in its husk. Could you have found a more difficult tree to work on! :-)
    You do good work. And I enjoy reading your blog on a daily basis as well. Please keep posting.

  2. Thanks so much, Rick, for your regular visits. Well, we have to deal with what we've got. The tree itself is rather majestic and it was here first. I work with a list of plants that can tolerate our messy juglone-producing tree. Picking up all those walnuts (and weeding out the ones the squirrels and chipmunks plant) is quite the task. Margaret inspired my post, of course: her photos are such a good lesson on the topic.

  3. Anonymous10:13 PM

    Yvonne- I've been enjoying your blog for an year or so.

    I was also thinking about under planting the other day.

    I was thinking about getting drought tolerant plants assuming under-the-tree plants won't get as much as rain. So I was quite surprised to see you are planting hosta there. I love the look!

    Do you water them regulary? or irrigation system is setup there?

    All my trees are quite away from our house and in full sun, I'm very curious how you keep them so beautiful...


  4. Thanks Jacky. About your question, I don't have irrigation there, but I do in my other shade garden area, which is also under challenging trees - spruces and pines. I water the area under the walnut tree, but only when necessary. When I water, I use a sprinkler and let it run for an hour and a half, so the plant roots really get a good drink. I think the secret to success here is good soil. Our property is on a rich, loamy clay-based soil that seems to be perfect for a lot of plants. I didn't do much to the soil under the walnut: added some leaf mold and mulched with wood chips. I don't give my hostas or other perennials any fertilizer and I water deeply, but infrequently.

  5. Great post and comments Yvonne! Your garden blog will always be my favorite, just so you know!!
    I don't have many trees to underplant yet but with my "oak nut" coming I can think about the future! I have a little stand of native Hawthorn trees (that I actually prune up to make them look like trees) I had thought about underplanting but I quickly realized there are some trees that this technique would not work with! I'd have little hawthorn bushes comming up everywhere!!!

  6. Hi Eve: Is it because the hawthorns self-seed a lot? I'm constantly weeding out little shrub seedlings, and walnut seedlings under my trees. It's just the price you pay when gardening, which might be defined as "controlling growth".

  7. Hi Yvonne,
    The hawthorns send out sucker roots that grow up into new trees (bushes). I've got some suckers starting in a spot where I keep a geranium that is at least 10 feet away from the closest tree!!!

  8. Anonymous9:16 PM

    Thank you Yvonne!

    It's the soil... And 1.5 hour watering!! I do only 30min for most of the bed, and once a week of treegator for younger trees so far... I will have to check how thirsty they are tomorrow morning... :)



Thanks so much for visiting this site. I have a new country garden blog and I will no longer be publishing comments at this blog. If you have a question or comment about the topic here, please use the contact form at my new blog to get in touch with me.

-Yvonne, aka Country Gardener