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Under a giant Douglas Fir

Posted by dottyinduncan z8b coastal BC (My Page) on
Mon, Jul 24, 06 at 10:52

I'm giving up trying to do anything under this fir. The soil is thin, dry, impossible. And the land slopes beneath it. Unfortunately, this wasteland is right at the entrance to our home, alongside the pathway. I'm now thinking about just putting stones, bark, anything that doesn't need any attention and looks presentable. Perhaps an interesting rock? I'm not good on design -- any suggestions for me?


Follow-Up Postings:

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RE: Under a giant Douglas Fir

I have tried to avoid planting anything that is inclined to take over an area, but.... lily of the valley does very well under my big fir and cedar trees. It (and the others listed) receives no water and smells great in May! I also have hostas, soloman's seal, hellabores, epimedium and evergreen huckleberry (that one required occasional summer water for the first two summers). Oh, and a hardy fuschia near the dripline which receives no water and does great as well. I am often amazed what can thrive with little or no help!


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RE: Under a giant Douglas Fir

Vinca major is planted under some of our cedars, and makes a dense circle 2' high out to the shade line, always looks great with glossy leaves, can survive without any water, though it will wilt a little under stress. It only blooms in the spring. It will totally obliterate any weeds. There are some pretty variegated ones too. The one with a lot of white variegation is not as vigorous and doesn't spread as fast. Vinca minor probably needs more water and doesn't spread as fast but also stays close the the ground and wouldn't get as tall. It has some lovely variegated forms too.

Winterberry is a #1 choice plant I have under another cedar, always looks impeccable and has little white tubular flowers followed by edible red berries.

I also have some rank but vigorous plants that will live in that environment- *Symphytum iberis, ground-cover comfrey, spreads fast, coarse hairy leaves, blooms in spring with tubular flowers that go from pink to blue to white, also good for dry banks.
*Geranium macrorrhizum- dry shade under trees or sun on banks, spreads fast, blooms pink in spring.
*Lemon balm- you definitely don't want this invasive mint but it does have a lovely lemon taste and is medicinal, I have it under a cedar where it does great, and at least I can tolerate it there.


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RE: Under a giant Douglas Fir

Thanks for the suggestions. I always try to stay away from invasive plants but perhaps this is the time and place. I do have some St. John's Wort around the actual base of the tree so perhaps another planting would work. What about knick-a-knick -- will it survive in such a moonscape condition?


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RE: Under a giant Douglas Fir

Have you considered Sword Ferns, Oregon Grape, or Salal?

All will tolerate the dryness within the drip line once established, like acid soil, and have very shallow roots.

Take a trip along the west side of an Oregon Cascade peak, and you'll get a good idea of what will do will do well under Douglas Firs.


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RE: Under a giant Douglas Fir

My kinnickinnick is under a Cedar tree, but the soil is not thin or poor. I think it would benefit from some compost or humus, and require some watering to spread though it's not a plant that needs much moisture and never visibly wilts. It spreads slowly, but mine is now about 3' x 4', all from one 4" pot. I had it for a while in a sunny bed with better soil and it was spreading more vigorously. It's not the blockbuster weed overcomer that Vinca major is. I really like the look of the VM and it sure beats the weedy grasses I was fighting there before I planted it.

There's another planting I have under a very large Bigleaf Maple of Wood Anemone and Sedum spectibile. The Anemone is dormant during the dry part of the year then starts growing in early spring, makes a blanket of leaves and cute flowers, then goes dormant again when things dry out. The Sedum is blue-grey and looks cool and luminous in the shade, can take dry conditions, and blooms too.


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RE: Under a giant Douglas Fir

One thing to consider when looking at plants that are thriving under firs and cedars in native forest situations is that the smaller plants that are there "co-evolved", in effect, along with the tree as it grew.

Trying to establish new plants under a fully mature tree is another matter. There is the full shade, full drought condition to take into consideration.

Trying to dig out a pocket within the root circle of the big tree, then filling it with compost, and then planting the new shrub or forb, and then trying to keep it watered until established enough to compete with the mature tree roots that will invade the new soil-- is what the challenge is.

I have not even been able to get sweet woodruff to establish in those conditions.

But I do keep trying with many of the above mentioned plants.


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RE: Under a giant Douglas Fir

Exactly what someone said earlier:

Sword fern, Oregon grape, salal. And add evergreen huckleberry to that, maybe even yew if you have space.

The key is to plant them in early October just as the rains start. And mulch the ground very good.

Have you ever been in the older growth PNW forests or in the Redwoods forests of CA / S. OR?? There are ferns and other plants under the canopy of those big trees.


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RE: Under a giant Douglas Fir

I was going to add that I have a vigorous low growing (max 18") large flowered (3") St. John's Wort that has covered a huge circle under a big fir. I see that you have discovered this also. I got mine from an friend who had no idea of variety or original source and have since passed it on to a few friends with similar situations. I shovel prune it when ever it gets beyond the deep shade and there are always takers..... What about other varieties of St. Johns Wort? jwww


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RE: Under a giant Douglas Fir

St John's wort is extremely prone to rust problems which tend to result in uniformly brown and dry foliage by midseason. A stress-producing location, like the dry shade under the canopy of most large conifers, is inclined to exacerbate the problem. And it is also an extremely aggressive spreader and seeds easily with bird droppings.

Depending on the degree of shade involved, there are a good many plants that can establish and thrive in this situation - some of the natives already mentioned are excellent examples. More ornamental choices are epimediums, lamium, low growing sarcococca (S. hookeriana var. humilis), Geranium nodosom and macrorrhizum, Euphorbia robbiae, Dicentra eximia or formosa. A number of taller growing shrubs and perennials will also work in this situation, but as noted, are harder to establish than smaller groundcovers.


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RE: Under a giant Douglas Fir

Until gardengal48 mentioned it, I had forgot about the rust on St. John's wort.

It definitely can get dusty and rusty in certain conditions.


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RE: Under a giant Douglas Fir

Hmm, one other idea I had- maybe Sedum?

I've had great luck some varieties (S. spurium, S. hybridum) in my shade garden (Sequoia, Spruce, Ferns, Hostas, Coleus) and they don't need summer watering aside from what comes down from the sky, and it comes back from winter wet and cold fairly vigorously.


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RE: Under a giant Douglas Fir

Thanks for all the suggestions -- but I still have problems. When I look at the site, it gets a huge amount of sun, even though it is such a huge tree. The branches don't start until 40 feet up and there is a lot of south sun. Also, we have a deer problem so sedum is out -- they love it! I am wondering about desert, rock plants.


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RE: Under a giant Douglas Fir

Sure, look at plants commonly used with xeriscaping. Many tend to like pretty lean soil conditions as long as drainage is sharp. My own Doug fir monster is limbed up pretty high as well, allowing a lot of afternoon sun, but over the years I have added a lot of shrubs to this area (and other trees in the general proximity) so that now the area only receives periodic sun and most dry shade plants thrive.

Perhaps it's just my preference, but somehow desert or xeric plants just seem to clash with this classic NW conifer.


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RE: Under a giant Douglas Fir

  • Posted by bboy z8 WA USA (My Page) on
    Fri, Aug 4, 06 at 18:15

I don't know if this came up already but creeping St Johns wort also burns during the winter in many positions, so you have to clear away the overwintering foliage early each spring if you want to be rid of it (as gardeners here often do with western sword fern).

If you put down bark and do some summer watering birds will often poop berrying shrubs and trees into such spots, giving hints of what might be planted by the gardener:

Cotoneaster
Hawthorn
Holly
Ivy
Laurel
Oregon grape

Most of these could be viewed as weeds, of course, and one or two of them are now being officially listed as such--mulched and watered but otherwise dry places under conifers in gardens not being the only locations perching birds will produce a carpet of seedlings here.


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RE: Under a giant Douglas Fir

Definitely salal. Zero maintenance and looks good.

HTH

MG


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RE: Under a giant Douglas Fir

Will Oregon Grape and Salal establish themselves if I plant them in the fall? I can dig holes in places under the tree (or have someone dig holes), and try to get them established in the rainy season. I agree that desert plants don't match our green PNW but this area is really shaby in an area that is the first thing everyone sees when they visit. I have an irrigation system but it can't extend to this triangle because of permanent pathways around it. I don't mind hand watering to help new plants but after that they have to be on their own. I truly do appreciate all of you that have taken the time to try and help me -- it's a great forum!


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RE: Under a giant Douglas Fir

  • Posted by bboy z8 WA USA (My Page) on
    Sat, Aug 5, 06 at 23:52

Salal can be quite recalcitrant, typical Ericacae in that it refuses to grow if situation doesn't fall within its rather specific adaptations. There are lots of salal patches under Douglas firs in this region, but trying to get some going deliberately in a spot that does not have them already may not be so easy as this would seem to imply.


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RE: Under a giant Douglas Fir

I'd also add that salal is not necessarily "zero" maintenance. In addition to the fussiness of specific location as noted above, it does experience some rather significant fungal leaf spot, especially in cultivated situations, is prone to root weevil damage and if happily sited, can get to be of rather imposing height, requiring pruning to keep in check as a groundcover.


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RE: Under a giant Douglas Fir

I also have a huge Douglas in my front yard and we just decided to dig a circle out around it and lay down garden fabric and (my husband want to)bark it. I read earlier someone mentioned planting lily of the valley, I have been growing Lily of the valley's in another place and would love to have them growing under the Doug, but how would I go about doing that? Should I cut holes in the fabric all over and plant them and then bark over? Is there any other way? I have had trouble in other beds do it that way with other plants. Any ideas and help would be appreciated


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