Dig a one foot by one foot hole, fill with water, empty it with a cup, fill again. If there is still water in the hole after one hour, your soil is poorly drained and should be amended accordingly.

And do you ammend the entire bed or can you ammend a hole or a section at a time?

It depends on how poor the drainage is, your budget, and what/how many plants you want to plant. If you have exceptionally poor drainage (i.e., the water goes nowhere after a couple days), you can either plant perennials that accept soggy soil like Acorus or amend the soil with compost at the rate of 1/3 compost to 2/3 native soil. You can start with amending just the areas where you want to plant, but you still need to amend a significant surrounding area or else you risk creating a bowl effect where the water drains out of the amended area only to back up wherever it encounters the dense clay (this is assuming your soil fails the one hour drain test).

Just because you have clay does not mean you have poor drainage. Many clay soils drain just fine, especially if they are exposed to organic matter and not compacted. I have areas around my house with clay compacted from construction where water will sit in a hole for days before draining. I have had to dig 3 feet down and basically replace the soil it was so bad.

daysquid, where on the slope is this? Obviously, the top of the slope will be drier than the bottom, and you'll have to plant accordingly. I have this situation on a much smaller level than yours (looks like you've got quite the slope there!). On my slope, the top is quite dry and the bottom is a swamp!

Dee

Also, another way to cheat poor drainage is to raise the bed 6" or so.

This is the bed that I dug the hole. It was thick with ivy and we have completely cleaned it out. I placed the hole in the center -- or mid way down. I dug the hole 12" deep and wide at 7:00 tonight. I just went outside (in my bathrobe) and it is down 6". So it drained 6" in 5 hours. What do you think? Adding 6" to the top might be an option and ammending large sections.

That does indicate poor drainage. I would definitely improve the soil structure with compost and raise the bed (if you can; I am not sure how susceptible to erosion it is given it is a slope). Water always takes the path of least resistance, so the soil may stay fairly dry since most of it probably runs down the slope. If it does, drainage may not be the primary issue since the water isn't really penetrating the soil.

One option is to terrace the slope, perhaps in line with each of those brick terraces, then amend/raise the soil level within each bed.

this conversation needs to be about budget ... and i dont mean i want to know what is in your checkbook ...

what i want to know.. is it worth it to do it right.. or do we need to nickle dime it ... [which is my world.. so dont be offended.. we need facts] ...

i would also like to know what is on the unseen side of the area ... looks like poured concrete ... maybe you said above.. and i missed it ...

in a perfect world ... we could hire a landscape crew to come in ... till or break the clay to 6 or 12 inches ... add 6 or 8 inches of good stuff.. re-till .. and basically try to make a good soil in the top 8 to 12 inches ... and then throw in some architectural rock or terracing for soil stability ... all the while not falling off the area.. and having someone else carrying all the soil to an inaccessible spot ... including the machinery needed .. [a boy can dream]

and as noted... loosening up all the soil can create bigger problems.. in a heavy storm.. if it all decides to sluff off downhill as it becomes saturated ...

or are we dealing with how a squid is going to do all this in her spare time ... or is the squid a he ... perhaps androgynous .. lol ...

and as a comparison ... in my sand .. which you have seen ... i can dig a hole the size of a 5 gal pail.. fill the pail.. then fill the hole with it.. and once it breaks soil tension .. the hole will be empty in about 5 minutes ... and that is the bipolar opposite of your drainage ..

you know.. i am getting to the point of thinking you need some onsite opinions of this.. and then you could come back here.. and ask us about what they said ...

ken

If it takes five hours to drain 6 inches of water, that is definitely poorly drained. If you have a layer of hardpan close the surface, no matter how much you amend the soil above it, the drainage through it, will not improve. I would start digging and see what your soil profile looks like. If your impenetrable layer is not too deep, you may be able to break it up. Other wise I think growing in raised beds is your only option. Al

Ken is right about balancing budget with improvements. It looks like you've got pretty poor soil and it doesn't drain well. Clay soil like you appear to have also compacts easily and becomes impenetrable to water, roots and even worms.

So, a couple of questions:

When you cleared it, did you see any earthworms? If not, you've got barren clay that is probably compacted and you need to add organic material i.e., compost, manure etc. no matter what you want to grow. If you had earthworms, you probably need to think about a mix of compost, sand, and even claybreaker to fit the type of garden you want there.

So, what type of garden do you want on this slope: just something to hold the soil and provide some privacy and as care-free as you can get in a garden? Or at the opposite end of the scale, is this going to be your beauty spot that you want to fiddle with, and create ooooow-ahhhh vignettes?

Obviously the more complex the garden you want, the more accessible you want the beds to be and terracing is going to offer you more and easier access. Even as simple as how do I get to plants to deadhead or cut back. So you also need to include access, stepping stones or places for that access in the terraces, so you can work on the level above, in your plan.

This doesn't look like that big an area. You may be able to terrace it yourself with a choice of lot of different materials. (you'll see four different types of terracing at my house; some I did, some the home owner before me) Then add your compost etc as you create each terrace. Work from the top down and cover the rest of the slope in a heavy layer of mulch until you have time and budget to put in the next terrace.

Or plan the whole area as evergreens flanking ground covers and just plan on amending bands across the bed as you plant them, making sure to overlap amending. Or lay back and plant something that will grow happily in wet clay as a ground cover.

The one thing you don't want to do is to do your amending by the planting hole. 1) This creates borders that will pretty much limit root growth and creates little tiny islands of even moisture, and 2) makes it much harder to amend soil as you add new plants. While you have an empty bed, it is so much better to just dig compost, sand, clay breaker, manure, whatever you need across a whole swath or the whole bed at one time if you can afford it.

You guys have given this she-squid tons to think about. To answer the question regarding design,there needs to be a path cut through this triangular garden from the top to the cinderblock wall at the bottom. My husband cuts through this bed to load firewood below across the length of the retaining wall.

So, the path will start up at the top and meander down to the retaining wall so he can make his way with a dolley of firewood and load the wood from above. Lovely. I just hate it.

I want to have lush hellebores on the side abutting the brick stair and then a mixed border of shrubs up against the back where we will install a fence to give us privacy from our neighbor.

Back to drainage solutions. As these are two beds with a path between, it appears you suggest that I need to break up a foot of the clay and then top the beds with 6" of compost. And what kind of tool do you use to break up 12" of dirt? I'm just trying to understand what is involved and if this is exercise fit for me or a landscape crew.

And as for terraces, I guess this wasn't part of what I envisioned but clearly I need to give this some thought.

A few more things, I did find a worm when I dug the hole. So I was hopeful. My husband also rototilled the beds but it was a little machine and probably only cut into the clay 2". When he finished he asked me, "Do you think this is good?" I replied, "yes." I've shared that we need to go 12" down and he remarked something about me building strong muscles. Got to laugh.

have you considered that the hard pack was put there ON PURPOSE ... so that water does not get behind and collapse the wall ...

if you live above the wall who cares..

if that is you down below.. crimminey.. you want the whole wall ... soil.. and the house above come floating down ... ever have a hurricane near Annapolis ??? .. torrential rains .. ????

i will yell...

YOU MIGHT WANT TO CONSIDER INVESTING IN AN HYDRAULIC ENGINEER TO DETERMINE WHETHER YOUR PLANS INTERFERE WITH YOUR SAFETY ...

there may be a dam good reason why that soil is there [pun intended] .. and why it was planted with scrub [because nothing else would grow in the engineered soil ...]

is the soil any different in other areas of the property??? .. if everything else is sand.. and this isnt.. that might be a clue ...

now see link

ken

Here is a link that might be useful: link

try this one

ken

ps: i claim no heritage .. was at a marching band show last night.. and one band featured this song ... i was actually sober in the 80's ... lol ... and disco was dead.. but that left us this .... is the other one actually better??? .. lol

Here is a link that might be useful: link

Ken - Love the links. Who knew a forum could have so much entertainment value. And yes, we live in the green cottage at the bottom of this slope and then the slope continues behind our house into a wide creek. We actually danced with a structural engineer when we bought the house 2 years ago. The retaining wall is in great shape althought he said that the 1920's cottage was a tear down. And we didn't tear it down. He later apologized and said our house was similiar to his own beach house.

We were at a friends house tonight and they said they have a heavy duty rototiller that could go down 10" - 12". We also discussed the possible need for a bobcat and hauling clay away. Hubby didn't like the sound of that. Kimka's suggestion of Sand and claybreakers were also discussed but no one knew what claybreaker are.

When I dug the hole I would say that there was 2" of softer stuff, then 3-4" of the more orangy/brown clay, then below that it was a darker brown color. This darker brown color stuff also seemed softer than that mid-section of clay.

Additionally, I called a landscape company today. We have so many projects with "this old house" that this is not this year's priority. But I'm curious to talk solutions and budget. I have 7 hellebores to plant! Thoughts on rototilling? Claybreakers? A short term solution?

We actually danced with a structural engineer when we bought the house 2 years ago. The retaining wall is in great shape

===>> thats not what i said.. i asked if the wall can hold back 8 feet of sodden soil

ken

You're right -- we didn't ask the structural engineer this question or any questions related to landscaping. These are all new areas of discussion. Perhaps I need to get several landscape firms to come out and propose solutiosns/give estimates. Would you separately consult with an engineer?

Clay breakers are mostly garden gypsum; sometimes they are combined with compost. Gypsum improves friability and drainage in the heaviest clay without affecting the soil's natural ph. The reason is that heavy clay compacts and drys into a concrete like texture that repels all water, air and roots. Gypsum keeps the soil loose, but it is not used up by plants like compost, so it continues to keep the soil fluffy year after year.

DO NOT EVER GET BUILDER'S GYPSUM, WHICH HAS CONCRETE IN IT!!!!!.

You know there may be an easier way to deal with these areas, especially if there are structural issues involved (the importance of which Ken is right about, as usual).

Since you would have to do some major soil amending to grow most plants anyway and you have slopes and paths issues that have to be dealt with. Why not just plan these areas around some really major containers. By staggering the heights of the containers, you could create the same feeling as terraces, fill them with good soil to begin with, design a path that makes hubby happy and doesn't look awful, and build drainage in as needed to direct the water away from your house.

And working above ground height in your garden sure is easier on the back.

To see what this would do, draw the area to scale, start trying out path lay outs that meet DH�s needs and then measure the remaining land. What size containers will fill it? Any container that you can make drain holes in will work: horse troughs, big plastic tubs, wash tubs, big drain pipes if you like round, hypertufa. You want to use containers that will never rot because these will be heavy once filled with soil. You can spray paint if you want color, face with rock or brick and mortar, stucco. Imagination is the limit. The container must be something that won't crack in the winter from freezes.

Use one big container on each side of the path or a couple to create irregular shapes or curves. The bigger the containers the better because they won't dry out as quickly in the summer and I would avoid clay pots or tubs because they dry out faster than a non breathing material.

If you choose something taller than 18 inches, fill the bottom with gravel or even Styrofoam and then about 14 inches of soil. You want to leave room to mulch the containers just like regular beds to keep weeds out and moisture in. You may find that every few years you need to add some soil, but that's not that hard. For big shrubs and small trees you would need really big, deep containers like they use in conservatories.

You could make one or more water containers (as long as you design in mosquito controls like fish or dunks

Then for your paths, think materials that won't be lifted by running water: bluestone dust, gravel, and I would go porous so water drains down as much as possible rather than rushing down the path (I'm assuming you plan to switchback the path at least somewhat. Or you'll need to figure out where the water is going to and install black drainage hoses to take the water where it will do no harm or erosion. You would not want to use anything organic on the path because the idea is you don't want weeds to ever grow on your paths.

There is no reason you couldn't create a completely natural looking garden as if you had simply terranced and planted in the soil or something unusual.

I see you've asked for a short term solution. Being an inherently lazy person I'm all about short term solutions.

First of all hellebores are hardy plants and will love your slope, clay soil or not, but they won't want to sit in water. Plant them a little higher and try no to plant them in pits. As you can see from your drainage test a pit will hold too much water, even if it's filled with the perfect soil.

Get some bagged compost or find a spot where leaves have accumulated and decayed, dig that good stuff into the top 2-3 inches of looser soil, and plant the hellebores into that layer. Mulch them. Use whatever you have. Decayed leaves would be perfect (but not pretty) wood chips or shredded bark would be fine but you want something that rots and feeds the earthworms that will work up your soil (so you don't have to).

Free wood chips from a tree trimmer would be a perfect mulch. They decay fairly quick, feed the soil, look ok and haven't been treated like many of the dyed wood mulches.

I like the container idea too, great way to accent an area that might otherwise be a sea of mulch.

Well it looks like I completely goofed. We had a huge tree removed between our home and the neighbor's. There was probably 2" of wood chips over the entire bed. I removed them. Darn, darn, darn! Looks like they should have been left in place. I guess I'll write about this newbie mistake one day.

As for containers, I'm not sure how they would sit on a slope but I've been really contemplating kimka's previous terrace ideas and how best to ammend the soil. We have two landscape firms coming out for a site visit. If I decide to go for a short-term lazy solution (and we cover off the structural concerns with landscape firm), I'm thinking we will rototill the hell out of the border next to the stair, mix in claybreakers and organic material. I'll plant the hellebores and then next spring do the much bigger mixed shrub border with the help of landscapers.

First landscape firm is coming at 2 on Tuesday. Looking forward to it. Thanks again for all your suggestions. And I'm going to look more into containers just having a hard time visualizing.

Just so you know, you need an engineer, not just a landscaper when you are talking about soils and retaining walls, so be sure that your landscape firms have one who can look at your situation.

nhbabs - Thanks for the comment. I definitely didn't make that clear when I called the landscape firms. I explained the situation with the possible need of terraces and I did explain we have another retaining wall that needs repaired/replaced. I'll follow-up and underscore the need for an engineer. Thank you.

Not that I disagree with any of the discussion. I agree with an 'on site' evaluation. But ... I'm curious if anyone has considered the option of working with what you have and use plant material that prefers moist conditions and wouldn't mind the poor drainage? Not having a spot on my property that is 'moist' I don't have a list of plants but plants grow in marshes, so I assume there are some.

There is a lot about this discussion that strikes me as a bit 'off'. I've been trying to put my finger on it for a couple of days now, and it definitely revolves around the idea of messing with something that may not want to be messed with. It looks like a reasonably steep slope, and it is possible that any of this amending will either destabilize it, or just generally make a mess. For one thing, I'm not convinced that poor drainage is going to be any problem whatsoever for plants actually planted there. Slopes don't tend to be wet. Particularly something that looks like that, I'd expect most of the rainfall to run down the surface.

You might want to spend some time on the Tree forum, and get their views on amending planting holes. It looks like a decent variety of plant life can live there on their own, and I'd be very reluctant to fuss and possibly make the slope unstable.