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paigect

erosion control/sunny dry slope

paigect
12 years ago

Hi all, I have taken a break from the boards for a year or two as I was injured and not gardening as much as usual, but I am back at it! I would truly appreciate some help with plant selection for a project.

We have a new house in Collinsville, which I am not moving into full time for a year or two. The front yard basically slopes down gently about 30 feet from the front porch and then drops off steeply to the street. The resulting steep slope runs most of the length of the front yard, parallel to the front of the house, about 40 feet long, and I would say it is about a 45 degree angle (unscientifically). There is no retaining wall, but there are cement steps leading up the middle of the slope.

Ideally, we would put in a terraced garden, but we don't have the time, money, or strength for that (really, we don't). So my plan is to try to plant the slope with some hardy, sun loving, drought tolerant plants/shrubs. I have never gardened under these conditions, so I would truly appreciate your specific plant suggestions based on experience.

The house is a small, 1840 farmouse, white, with a partial front porch. There are several old red barns in the very near vicinity, just to give you an idea of the setting. I would prefer a slightly cottagey look to a totally naturalized look, since this is essentially the front yard and it's a farm house.

I would also like to do a shrub border right along the top of the slope, which would run parallel to the front of the house, to help prevent further erosion off the edge of the slope. I was thinking fothergilla and smaller viburnum. Other ideas welcome. Again, it is full sun. There is already a row of yew which will serve as a background along the part of the house without the porch, so I don't feel it's necessary to add evergreens to the shrub border.

For planting the slope itself, I would really appreciate suggestions re: plants that can tolerate dry, sunny conditions, and that have deep roots to hold up the soil some. From my own garden I was thinking of bringing siberian iris, lady's mantle, and caryopteris. I'm not sure about others, like phlox subulata, various salvias, or maybe bearded iris? I would also be interested in small shrubs for the slope, both evergreen and deciduous (although I am not a juniper fan), but I'm really unsure what I can get away with here.

Any thoughts are very much appreciated. And I look forward to seeing some of you at the CT plant swap.

-Paige

Comments (9)

  • myonlysunshine
    12 years ago
    last modified: 9 years ago

    i was also thinking of creeping phlox,how about some lavender?mine is completely care free and is beautiful

  • paigect
    Original Author
    12 years ago
    last modified: 9 years ago

    myonlysunshine, yes, of course! Thanks for the reminder. I have two lavender plants that need to be moved anyway. So those will go.

    I think I am coming up with a plan of sorts. There is a stairway up the middle, which will allow easier access to the neighboring area. So I will put perennials all along the stairway on both sides. As we move out to the center of the beds that are harder to access, I will use lower maintenance plants such as shrubs and maybe sweetfern. I read that flowering quince is good for dry sunny slopes, and I love the old fashioned look of it - have one in my backyard now. Maybe a smaller forsithia, too, although it's not my favorite. And definitely a few baby conifers (birds nest spruce, maybe a mugo pine to draw attention up to the front porch) to create some structure and winter interest, if I can manage to get them established at a young age. Then along the outer edges of the beds I can use some things that require a bit more maintenance.

    I will use Marty's suggestion (from the CT plant swap post) of seeding wildflowers in the bare spots for the first few years, until things fill in.

    Any other suggestions for particular plants or shrubs are more than welcome.

    I so love planning a garden. More than doing the actual work, I am afraid!

  • Thyme2dig NH Zone 5
    12 years ago
    last modified: 9 years ago

    Hi Paige, your slope conditions sound very similar to what I have in my front yard. I have a farmers porch with a fairly flat 30' or so garden coming off of that, and then a fairly steep slope going down to the street. I planted a lot of low maintenance shrubs and they fill in so it keeps the weeds down. I used barberry (back before they were banned....), spirea, fairy and carpet roses and some evergreens plus other shrubs tucked in here and there. I then also have bulbs and perennials. Perennials include ground phlox, sedum, golednrod, aster, daylilies and some large single peonies that do not require staking. Plus a whole bunch more throughout. It is a slope for all seasons and there is a lot of interest. I planted the larger shrubs towards the base of the slope to mitigate how steep the slope looks.

    Here's a shot from summer:

    Early spring

    Fall (should have cut back those peonies earlier!)

    We have rocks at the bottom of our slope but even without the rocks I don't think we'd have a whole lot of erosion with all the plant material we have on the slope. I did have to mulch for the first few years to keep the weeds down and hold the soil a bit, but we stopped that years ago.

    P.S. I'd be broke if I moved to Collinsville. That would put me way too close to Cricket Hill! Love those tree peonies.

  • paigect
    Original Author
    12 years ago
    last modified: 9 years ago

    Wow Thyme, what an inspiration! Thanks so much for posting your photos and description. Your house and gardens are gorgeous, and so well designed.

    I love what you did with the two trees pointing up the staircase, staggered. I was thinking of doing exactly that!

    Our slope is quite a bit steeper. I like the idea of putting the bigger shrubs at the bottom to minimize the slope visually, but I am most concerned about the erosion on the very top edge. I am wondering whether I should plant some smaller shrubs just under the edge, or whether I should plant them on the top of the edge just before it dips off, to help keep it from further eroding?

    I will have to check out Cricket Hill, never been there. And thanks again, great photos!

  • runktrun
    12 years ago
    last modified: 9 years ago

    Gosh I love Thyme's garden.
    If you decide to go the inexpensive quick way you might check out Juniper 'Bar Harbor' at the nursery linked below as they sell flats of plants for very reasonable prices. kt

    Here is a link that might be useful: Holly Hill Nursery

  • NHBabs z4b-5a NH
    12 years ago
    last modified: 9 years ago

    One of your first goals will be to slow the water sheeting down the surface, both to reduce erosion and to increase the amount of moisture that soaks in. If you can afford someone to put in a few boulders that you can plant between, that might help. Even chunks of cordwood slightly set into the soil will help and can be left to rot or get covered by the mulch and plants. Use this sort of a shape if possible \__/ (sort of a sideways C with the opening facing into the hill and dug into the slope. You'll want to put down really fibrous bark mulch to help hold soil and reduce runoff while things take root. Another option DH used to hold a very steep slope was getting long wooden stakes (grade stakes) and pounding them into the slope perpendicularly to the slope to brace boards that help hold the mulch and soil while the plants established. Grade stakes are pretty inexpensive and he used slabs (cutoffs from the outside of a tree) from a small-scale sawmill. This wouldn't work with rocky soil, but we have no rocks, so if that's your situation it might help and is inexpensive.

    I think T2D's slope is a bit steeper in person than it looks in some of the photos, particularly on the far side of the steps. I agree that those beds are stunning!

    I have a quite steep bank behind my house (SW facing) and at the time I planted it had little time or money to deal with it. I did have a bunch of old orange daylilies crowded into a bed where I wanted to use the space for something else, so I transplanted those about every foot or so and they hold the soil well and have spread. (You may be able to get a bunch of these by offering to dig them on Craigslist or by just looking to see if someone posts that they are available.) I also got another medium height plant that spreads from another gardener (no idea what it is - screaming magenta daisy-like flowers and large coarsely toothed leaves) and the two weave around each other. I put a Korean spice viburnum (V. carlesii) a few feet up from the bottom of the slope and it has done well. A Kousa dogwood is at the bottom of the slope. I mulched it well and renew the mulch every 4 years or so. I'm only now starting to consider what else I might want to plant here, so I'll enjoy seeing what others suggest. When I plant on a slope, I take the extra soil from the hole and use it to make a wall below the plant and create a pocket to help hold water.

    As far as other specific ideas you mentioned above, you might want to reconsider the wildflower seeds as they tend to need a lot of weeding to get established, need sunlight to sprout (so no mulch) and may well wash to the bottom of that steep a slope. I'd put the Siberian iris near the bottom of the slope as they like it a bit less dry and may need dividing in a few years to bloom well. Bearded iris will tolerate dry soil, but won't help much with erosion as their roots aren't very deep or prolific. Sweet fern will do well anywhere on that slope as it will grow in any poor site IME, but it will sucker and spread, not remain just where you put it. It hasn't been difficult to pull out when I've needed to. I have a white-flowered 'Jet Trail' quince that suckers and is in a relatively dry situation (at least it never gets supplemental water and the soil is sandy.) It seems to top out in height at about 4 feet, but I have to periodically whack it back to reduce the girth as it gets more than 6 feet wide.

    Some other ideas that occur to me for your situation:
    Think about sumac - either one of the fancy kinds like fern-leafed or lowgrow or even plain old staghorn. It will sucker also, but is pretty unfussy and likes full sun. Birds like the fruits and the fall color is stunning.
    Junipers - come in different textures and colors
    The shrubby Caryopteris have lovely late summer purple-blue flowers. They are low growing and some have variegated or golden foliage, though the original types have bluish foliage.
    Many bulbs like to be drier in the summer, so they will help add interest in the spring and the roots will help stabilize soil. (daffodils and tulips would be a good start.)
    Nepeta and Russian sage come to mind as plants that will be OK.
    Ice plant will work if it's a kind that's hardy enough for you.
    The western Penstemons or Agastaches like it dry. I planted Agastache rupestris on a steep slope as well as Penstemon pinifolius (pineleaf beardtongue) along with some hybrid forms of both kinds and they have survived most years though they are borderline hardy here.
    Achillea and lambs ears are happy where it's dry.
    Look at High Country Gardens website for ideas of plants that like dry and sunny. I have found that many of the plants they sell (like the Penstemons and Agastaches) will grow for me on steep slopes. They tell you what is the precipitation range for each of the plants, but in steep areas I find I can plant things that like it a bit drier than my area is.

    Regardless of what you plant you will probably need to water some the first year if there isn't regular rain so things have a chance to get established and grow sufficient roots. Soaker hose below the mulch will help with this without increasing erosion potential.

    Here is a link that might be useful: High Country Gardens

  • terrene
    12 years ago
    last modified: 9 years ago

    If you are interested in native shrubbery two possibilities are Ceanothus americanus, New Jersey tea and Myrica pennsylvanica, northern Bayberry. New Jersey tea has beautiful white puffy flowers that attract butterflies and maintains a low profile. Bayberry is semi-evergreen and dioecious and the berries on female plants are enjoyed by birds. Bayberry berries are also the source of wax that was used to make bayberry candles.

    They are both drought-tolerant and would adapt to the dry, sloping, and sunny conditions you describe. 1 or 2 year old seedlings would probably take hold on your slope best, but you might have to protect them from rabbits or erosion the first year or 2.

  • Steve Massachusetts
    12 years ago
    last modified: 9 years ago

    This is such a common problem in landscaping. I have a similar slope that I haven't dealt with yet. I think the people posting on this thread have handled it so well. Thyme what a great piece of work your slope is, and Babs I've seen your work before and it's inspiring. Great thread. Thanks.

    Ste

  • paigect
    Original Author
    12 years ago
    last modified: 9 years ago

    Thanks, KT, for the nursery link - - they are quite inexpensive. I have never bought conifers that small, but they do have some I would be interested in.

    Babs, I love the idea of using cord wood to stop the flow of water. We have some at the house that we won't use otherwise. There is already a thick layer of chunky mulch on the slope and it seems to stay put, so I think I can just use what is there for that. I am also going with a quince and a viburnum, and will be transplanting and dividing my caryopteris over to there as well. My boyfriend has stated a preference for lots of color, so we will probably be adding some rose bushes as well (his favorite). I know they will need more attention and will try to put them where we have good access.

    Terrene, I had been thinking about bayberry as a filler. Will check out the tea as well.

    Steve, good luck with yours, keep me posted!

    Thanks, all for the great responses. They are giving me a lot to think about.