recap: 10 thoughts on successful underplanting

A COUPLE OF YOU COMMENTED when I posted a spring “walk in the garden” story years back, asking for help with the subject of underplanting trees and shrubs (including my oldest magnolia, below). True confession: I have come very slowly and painfully to this lesson, dragged by some much more talented friends, Glenn Withey and Charles Price of Seattle.

The lessons have involved some yelling, and even some tears (mine, not theirs). Still interested in learning how to “think mosaic,” as I now call underplanting (including in the little video above)?

underplanting of perennials under magnolia treeMy real education in underplanting began eight years ago, when (20-plus years into my gardening life) I learned the most important lesson of all: Ask for help, preferably early and often. So rather than remaining embarrassed that I wasn’t as confident in making complex and large mixtures of plants, despite all I knew about them individually, I asked Glenn and Charles to come and teach me.

Things got started really badly, and I feared for the friendship. The lowpoint was Day 1: I came around the corner of the house to find Charles (below, in full Pacific Northwest-style rain gear) holding my most treasured plant—in pieces. Without asking, he’d uprooted it and sliced it into tiny chunks. I shouted. He shouted right back. And so I cried, feeling out of control on so many levels.

underplanting an old apple tree with ground coversOf course Charles had done exactly the right thing when the goal is underplanting large areas, such as beneath trees: You need more, more, more of a few key plants to make it all come together. He was making more of my Hylomecon japonicum. At that moment, I didn’t feel quite so philosophical about it, however.

hellebores and other perennials underplanted below a treeA spring or two later, Glenn and Charles, who curate the wonderful Dunn Gardens in Seattle and have a design business as well, visited again for two days. Being much bolder now and with years’ more practice, I uprooted precious things myself with abandon—trilliums (divide them like this) and yes, the Hylomecon and goldenseal and other shade-loving treasures.

Hylomecon and other perennials underplanted below a magnoliaUnder two more big, old apples, we replicated the successful pictures they’d taught me to create under my oldest magnolia (above, with celandine poppy and Hakonechloa and Hylomecon in April) and oldest apple (carpeted with hellebores and more, two photos up the page) that inspired some of you to ask “How’d you do that?”

10 tips for underplanters

how to plant under a tree1. No ring-around-the-rosey, thanks anyway. Rather than circling the dripline of trees or shrubs (or a group of trees and shrubs) with groundcovers and bulbs and such, you have to get all the way in there, even right up against the trunk (like this old apple’s above), to make it look UN-manmade…as if it just happened.

newly planted bed of perennials2. No polka-dots (except at first): Like I said, It’s all about learning to “think mosaic,” which doesn’t mean polkadots of onesies, but sweeps and drifts and deliberate repetition of said sweeps and drifts. At first, though (as above in a newly laid-out bed under an unseen smokebush) no matter how many plants you buy or what you feed them, the new underplanting will look like hell (well, like polka-dots). Which leads to the next lesson:

3. Patience is required. (If you did not know that already, I suspect you have not started a single seed, let alone planted a young tree.) This gardening nonsense is all about patience—frankly I think it’s a patience-building practice more than anything else. Your bed will look better next year, and almost great two or three years after planting. After the fourth year you can start harvesting divisions of some plants to repeat your success elsewhere.

3a. Notice I say “divisions,” because when working in the root zone of trees and even established shrubs, you want to work with a small trowel or a hori-hori, and plant small things. I use divisions made from older plants, or order “liners” from my nursery (the baby plants they get wholesale in late winter, then grow on in their greenhouses to sell to you). No digging with a shovel (or tiller, heaven forbid) in root zones. Again, patience is required, and a gentle hand, too.

Hakonechloa, painted fern, European ginger, Hosta June4. Select a palette that relies on several key plants, with a few others as punctuation (the little gems to pop up from the carpet beneath them). Buy (or divide) so you have lots of each mainstay to get you started. The late-spring-to-fall palette under my oldest magnolia (top photo and above) is glossy European ginger, yellow Hakonechola macra ‘All Gold,’ plus Japanese painted ferns and Hosta ‘June,’ with a couple of young ‘Lime Rickey’ heucheras picking up the gold grass.

early ephemerals under magnolia5. Include ephemerals, early spring bulbs or perennials that come and take advantage of the sunshine before the canopy leafs out, then vanish underground or at least don’t take up much space. Winter aconites, or trilliums, or hylomecon, or Dutchman’s breeches, or bloodroot, or Virginia bluebells…the list goes on. Oh, dont’ forget twinleaf (Jeffersonia). I get about six extra-early weeks of color from my underplantings, before my mainstay plants fill in, by using ephemerals lavishly. That’s the same bed (just above), in April-into-May.

hellebore trillium hylomecon6. Include some “groundcover” types, meaning plants that form thick mats (but not English ivy or pachysandra or vinca!). I am partial to epimediums, European ginger, Hackonechola macra ‘All Gold,’ hellebores (above, in bloom), perennial geraniums of a semi-evergreen nature (like ‘Biokovo’ or macrorrhizum), among many.

Lilium martagon hybrid 'Claude Shride'7. Make space for some real gems. Gems might include species peonies, choice hostas like ‘June’ (a favorite of mine), or even bulbs, like an outburst of martagon lilies like ‘Claude Shride,’ above, or primulas, like the orchid-pink P. kisoana (below, in that same magnolia bed but another two weeks into spring) for an unexpected moment.

Primula kisoana8. When choosing plants, remember that leaves are your best friend. Plan on a mix of textures and colors, coming mostly from foliage (as the leaves will be there all season or even all year, and the flowers just come briefly). Think of the color range of heucheras alone you could employ, or hostas—foliage is hardly boring. Which relates to this lesson:

japanese painted fern and autumn fern 9. Texture is also a great ally. Work it. I cannot imagine “mosaics” working without some linear things (grasses like Hackonechloa, or sedges), contrasted against some ferny things (like, well, ferns; those are the autumn fern and the Japanese painted, above) and against some large-textured things (like bigger hostas, or perhaps mayapple, or its cousin Diphylleia cymosa, below).

Diphylleia cymosa

10. Once you’ve selected a palette, repeat, repeat, repeat. Not just in the first area you underplant, but (if it works) in another area in need of some extra interest, where it may be all mulch right now, or a sea of a single groundcover. Soon your first mosaic will fill in and afford you some divisions, and on to making the next beautiful carpet you will go (maybe with help from a great teacher like Charles or Glenn, below, having at it under another apple a few years back).

Glenn Withey planting perennials

  1. Sabrina J Funk says:

    So happy that I happened upon this as I am planning on attempting an underplanting project in the very near future. I found you via your interview on the Joe Gardener Show and I am so happy that I did…I do have a question, the tree I will be underplanting is a sugar maple and I understand that I have to be careful because they doesn’t like their roots disturbed but you stated that the plants should be right up near the tree…do you think I can still do that with a sugar maple? Do you have any advice beside all the good advice in this article if underplanting a tree of this kind? Again thank you for sharing all your knowledge!

    1. margaret says:

      I think if you work with very small seedlings or divisions of plants — not with a shovel but with a small tool like a hori hori digging knife just to tuck in things to tiny pockets — you can work where you like. As far as right up near the trunk, I say that b/c that’s how nature plants — not just in a ring around the drip line at the edge of the tree, but like a carpet.

      1. Sabrina J Funk says:

        Great! Thanks for the advice! Just bought myself a hori hori digging knife for Mother’s Day happy to put it to good use.

    2. Debra says:

      I live this post and find myself coming back to it again and again! But finding myself stuck though with how to actually place plants on a linear bed under a line of hemlocks that has soil on either side of it (wild ginger with some tiarella, bleeding heart, and ferns mixed in). The hemlocks have been limbed up quite a bit. Any advice on how to place these things without making it look “planned”? Should they be scattered throughout truly randomly or should there be any order to it?

      1. margaret says:

        I like the sweeps of each kind of plant to be more amoebic in shape, weaving into another sweep of another plant the way paisleys in a fabric interweave.

  2. Amanda says:

    I would like to plant under a large magnolia tree we have, but it drops such a heavy amount of leaves, I am not sure how to remove the leaves without damaging the plants. Do you have any suggestions?

    1. margaret says:

      I like the rake called Yard Butler that is not too heavy, and some people use a leaf blower (which I do not have). I use a lightweight springy rake and make very light motions when the stuff is as dry as possible.

  3. Hazel Norman says:

    How do you prepare the GROUND? Do I add compost? Potting soil? I need to know the how to in ground preparation more than what plants to plant. Nobody tells you what to cover the ground with so the plants can grow. Do you just add material in the individual hole for each plant? Help.

    1. margaret says:

      Hi, Hazel. It so depends on what you are planting and the condition of your underlying soil. Will write you a note.

  4. Anne DePietro says:

    I wonder if you could recommend some plants that would work well beneath wisteria. I understand wisteria doesn’t “play well” with other plants and I am at a loss at what to attempt the wisteria climbs up a trellis on the side of my front porch and while there is some sunlight, it is for a brief part of the day and dappled afterward. I’ve lost azaleas, some perennials I can’t remember. I was thinking of bleeding heart, heuchera, hostas. It is not a deep garden. Daffodils don’t bloom, my lilacs have thus far been disappointing. Help, please!

  5. Rob says:

    HELP! I have 60’ of under cedar drip line in my garden. Nothing grows there except black berry that I uproot every time I see a sprig, and a few volunteer indigenous fern. My garden area was all dense blackberry when I moved in. The trees run east west and get good sun on the south for most of the day. The soil is poor shale and gravel it will support northwest blend grass seed with disciplined fertilizer and water outside the drip line, but as the trees grow the drip line grows. I planted two rhododendron just inside the drip line about 6 feet apart three years ago. they did well, tripled in size, bloomed every summer, and just died this spring.

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