DG Seminar 1: Assessing Your Site

Okay, here we go :)

I tried to think of the first consideration in planting or designing with trees and shrubs. It seemed to me that assessing your site would be at the top. Any questions pertaining to site evaluation are perfectly appropriate, as well as any volunteer information or instruction pertaining to the topic.

So, here's my question regarding site evaluation:

In a site where more than a few mature trees are already established, how far away from those trees should you consider planting other trees and shrubs? For instance, if a grouping of mature, deciduous trees flanks the back border of your property, how far away can you plan on adding other woody plants? I'd want to add in some flowering, smaller trees or some evergreens if they were lacking, but I'd be concerned about the established tree roots. What's the rule of thumb here?

BTW, any recommended reading for site evaluation?

Thanks,
Jacci :)

edited for typo

This message was edited May 16, 2006 10:23 PM

I've had the same question. Thanks for posting.

Guy will probably chime in here for the expert. But I myself always planned my site around the existing trees. I have planted many trees to highlight these existing trees. IE a group of ponderosa I feel are beautiful when a planting of Acer is placed in front. The point is I always plant trees that I want in root areas of existing trees. Now In Montana we have a root pattern of 50 to 60 feet in diameter of our conifers. The only concerns are what the existing tree roots will do when raised beds are put over their root system. I have not seen one negative effect of over planting of different root systems. Also I have planned my new trees based on their size in placement and plan to cut away the closer natives eventually. I have plenty of trees so this can be done easily without making a dramatic change to the environment of existing trees. This bed is 18" deep and covers much of both of the existing trees roots. The Doug fir on the right will be eliminated when the Beech, Aspen, and True fir behind it become larger.

These are HUGE questions. I think the important factors include:

1. Health of the existing tree(s) you choose to save. This means not disturbing a significant part of the root zone, which can be defined very loosely as a circle considerably wider than the height of the tree. "Disturbing" could be a whole separate thread in itself.

2. Health of the new trees. Consider potential allelopathy, sun/shade requirements, hardiness, soil/moisture adaptability (including pH), disease/insect resistance, species diversity, and maintenance.

3. Aesthetic and other design considerations. This includes views, seasonal changes, light direction, formal vs. informal vs. natural design approach, microclimate affects (sun, wind, etc.), litter management, legal-type questions (regarding banned or invasive species, setbacks, easement clearances, etc.), and a whole host of things that vary in relative importance from site to site.

Sofer makes some very good points about anticipating the evolution of your landscape. Trees grow and change, and you should plan for that over time. Others will have much more to add, and I gotta get back outside and get to work, so I'll stop here.

Guy S.

I'll add that one should seriously consider properly identifying all existing species first and take an informal inventory of how many of each there is and where they are located. Once properly identifed, one can begin the arduous task of researching which species are deemed desirable and which are not. Many factors to consider when determining which stay and which go. From there, one will be able to determine other factors such as proper spacing which will vary wildly based on the species. I found it helpful to draw a diagram of my property. I placed little dots of plants that I inherited with notes on which species they were. I additionally denoted which plants would go to plant heaven either on their own or by my hand and made it a point to focus on getting an appropriate replacement established in the near vicinity. Case in point would be Ash trees. I am of the opinion those will be gone from the American landscape like the American Elm and American Chestnut in the not so distant future. If a plant has known issues such as an Ash... or an Albizia, why work it into a landscape design. Doing double and triple work got a little old for me after I first started plopping anything in the ground that appealed to me with wild abandon without having had a basic knowledge of all that I had here. Classic deal where in which if one is dumb... one pays. And pay I have and I continue to pay for my lack of properly researching what all was here.

Here's a good one for you and it is so representative of poor planning. I created an area complete with a footpath and ran electricity to it for a pump to a birdbath. I even had concrete benches that matched the stepping stones as well as the birdbath. It was to be my secret shade garden. A place where one could go to read a good book on a warm summer afternoon while getting out of the hot sun. I purchased literally hundreds of shade loving plants and spread them throughout this area in hopes they would take. When friends and neighbors came over, I showed them how my "secret garden" was progressing. Everyone thought my "creation" was going to be awesome. One big problem. That area was 90% Buckthorn and by the time I finshed clearing it out, I had to relocate every shade plant I had stuck in the ground because my secret shade garden was now full sun and not exactly secret any more. We're talking fully exposed. I'm no landscape designer. Does it show ?

LOL -- good story Equilibrium :)

And, thanks, everyone for your replies.

Piggybacking off the tree identification tip, aren't there certain trees that are notoriously difficult for underplanting? Black Walnut, for instance, is reputed to emit toxins that hosta cannot handle. Is this fact? Also, some trees have roots that grow so close to the surface that interplanting among them is arduous at best. Can anyone give me a short list of trees that would definitely fall into the "trash em" category if underplantings and interplantings were desired?

Gone to Chicago for a long weekend, but I'll check in when I get home :)

Alright, I was too specific in my question at the start of this thread. See? Didn't I tell you I wasn't sure what I was doing??? :)

So, I'll try to get things a bit more general...

In assessing a site, what are the main factors to consider. I know there are many, many that could be mentioned, but which ones really top the list?

I can at least intelligently comment on a portion of this answer :) Light and shadow patterns are critical. And not just over the course of one hour. If you go out and look at your yard and try to decide where a shade bed is going to be after just one look at 3pm in the early spring, you could be in for some major surprises when you plant shade-lovers and the site is in 6 straight hours of sun come late July. LOL -- speaking from experience here :)

As hard as it is, and I know it's really is hard, it's best to assess a brand new site for an entire year before launching any major landscaping plans. Light patterns change dramatically over the course of the day and over the course of the year. For instance, certain plants (like broadleaf evergreens here) require protection from winter sun and winds. It'd be pretty tricky to assess the degree to which a plant would be protected months in the future, unless a mature canopy of evergreens was already established or some other exception.

Several sources recommend charting the light/shadow patterns over an area every hour throughout the day. For instance, note the light patterns at 7am, 8 am, and so on until dusk. Areas that already have mature trees and shrubs can have full sun and shade within a foot or less of one another. It's important to pay close attention to the light. The right plant for the right light is a big first step to getting a planting off on the right foot.

Huga

I have a landscaping program that tell me the shadow patterns and I keep a permanent record of the major plantings so I can plan the next bed. But I always usually know what is going to happen by me being out there often working, watering, and planting.

We moved in to this house 2 years ago, it was a new build. I could not stand the site of absolutely nothing planted. I dove right in, planting trees and getting beds shaped out. I made a big boo-boo, though, with where I thought the house would cast shade for most of the day. It did in August, anyway ;) The following spring I began planting all kinds of hostas and shade plants...ummm... well, that bed didn't start getting shaded from the hot afternoon sun until mid August. Poor little guys. Gave nearly all of those plants away. I have zero shade.

A landscaping program would certainly be nice :) Do you have to record the height of every plant to get those patterns. For instance, a tall perennial casting just enough shadow for partial shade plants, etc.?

I always loved my goof ups cause I could always find a spot in all of my raised beds. Now its getting hard. More beds.

LOL -- not a spot of shade to locate my poor goof-ups into :( Oh well, I'm learning to love my sun plants :)

But, back to trees and shrubs.... ahem.... assessing our site. What else? Soil? pH? Water needs? More about light assessment?

edited to say that they changed my DG name tonight -- bye bye huga! So, hugahosta = SalmonMe

Jacci :)

This message was edited May 22, 2006 12:33 AM

Jacci, I loved that Huga name. SalmonMe just does not have the same ring, even if your husband is Sam. I mourn the loss of your good old name! Can we still call you Huga?

I thought someone would bring up the physical features of the site by now. Wind exposure, drainage, utility lines, traffic patterns, access routes for maintenance equipment, soil depth, etc. That really should be the first step.

And if you are starting with a blank slate, TOTAL site prep should be the first action following assessment, including (as needed) deep-chiseling, grading, organic matter incorporation, and pH adjustment. Never start plugging new plants into an unprepared site, despite how much fun it is to get those first plants into the ground. Once the plants are there, you've forever lost the opportunity to fix the substrate. If you just gotta do something green that first year, plug in a few expendable annuals.

Guy S.

But Guy that would mean to make a ;;;;;;;;;;;; plan. No No No not me please. I know Hugga will be much better off with you wisdom. You must have a big cranium cause you are very logical, practical, and informed. Mine isn't and I have to turn off one to get the other to go to work. I can't wait to see your forest.
SalmonMe you are copying a name of a Alutik native here in Kodiak. I'll have to ask her if it is OK. They are wonderful people so I'm sure it is.
OK one only addition. When we were buying our house we took a shovel and bender bar to see the topsoil and what we started with. I suggest not to look at the house just pick a soil area that is superior for the area and use the house for compost.

LOL -- an Alutik native, eh? And Guy doesn't approve of the new me. Hmmm... sorry, it's a done deal. I have to admit, though, that I was kinda sad the first time I logged in under the new name. But the hosta questions were forever coming, not to mention routinely having to retell the story of my move and how now I have no shade and "how many hostas do you have?" answer: "none"... etc. I had to ditch the hosta connection. Sad, but - oh, well :)

I would like to get into the site prep question after we "dig" into site eval first.

Utility lines are a majorly overlooked component of site evaluation. It drives me nuts to see trees planted directly under these things! In Virginia, many of the trees in nurseries came with tags that read "Look Up!" and had a drawing of powerlines. Looking up at where the poor tree is going to grow in 20 years can save it from being chopped and marred beyond recognition at maturity.

It's also imperative to "Look Down" and call the utility companies before you dig. Planning a major digging project right on top of your gas line could be a problem, for instance.

I'd be interested in hearing more about assessing wind exposure and how that interplays with the design process...



This message was edited May 23, 2006 1:15 AM

So, if you're looking at a property with virtually no windbreaks (there's a lot of it here, ya know), the consensus is to plant evergreens to the northwest, I believe. Beyond that, Guy, I'd love to hear more about how your 3 points play out in practical planning. I think I can pretty much visualize #1, that's fairly straight forward. Make sure plants that need protection have barriers from strong winds that might knock them down or cause dessication, likewise provide enough space and air circulation around plants that need it to avoid powdery mildew or other disease issues. Sound right?

I read my hubby your other 2 points. He said something to the effect of, "Dude! He knows his stuff!" LOL :)

So, "dude", how exactly would one design for summer breeze channeling? Limbing up the lowest branches on existing windbreaks here and there? That's my best guess :) How do you hit the right balance between blocking gusts and encouraging pleasant breezes?

This is fun! Thanks!

edited for typos


This message was edited May 22, 2006 11:15 PM

Huga (oops, sorry, I mean Salmon!), think of your plantings like a funnel or like buildings along a city street, concentrating the summer breeze where you want it. Stronger winds generally will be reduced overall as they narrow to pass through the opening and expand again, and winter winds generally come from a different direction and can be blocked at ground level for a downwind distance of up to ten times the height of the trees. We are not talking exact science here, just qualitative analysis.

There is so much more to it if you want to really explore it, and most people don't bother. Like I said up top, these are HUGE questions and they are impractical to address fully here. Things like wind management, noise attenuation, and microclimate influences are topics for landscape architecture dissertations, not a forum thread. Just be aware of the possibilities.

Guy S.

Aw man, but I want a landscape architecture dissertation! I'm kickin myself for not choosing a different college major. If I was going to be a stay at home mom anyway atleast landscape could've been used toward my hobby! LOL :) Maybe that makes me not most people, but if you want to go on and on I will happily listen :) I will call you Sensei...

Grasshoppa

Maybe if you really think that the material is inappropriate for a thread, you could recommend some reading material that discusses these finer points? Just a thought, Sensei :)

You still could take an LA course or two -- what's stoppin' ya? Then you'd learn all the stuff most of us have forgotten and you could come back and help us all remember. Besides, I haven't used most of that stuff for decades and I'm way too rusty to be your mentor!

Guy S.

Salmon, Sensei is the PERFECT moniker for Guy. I love this thread.

-Joulz

No, no Sensei!!! Grasshoppa take care of 3 small children and is home school mom. Free time not for expensive class!

Seriously, I've looked into some correspondence stuff, but nothing more than that. Money and time, Guy, money and time. If the class was at 10pm and just down the road.... maybe :)

Okay, earlier Guy mentioned traffic patterns as a good thing to consider up front as well. I guess this could really be seen in several different ways. The two that come to my mind are:

1) Traffic patterns you want to encourage

With pathways, or at least clear walking space. Where are you most likely going to walk to get from here to there and what surface do you need to sustain that kind of foot traffic? Keeping more sensitive plants well within clearance of these high traffic zones.

2) Traffic patterns you want to discourage

Where folks are wearing down an eroding slope with corner cutting, for instance. Or where neighborhood kids/dogs keep running through your property and trampling plants. Seems like a nice prickly barberry, holly, or rose would be a good deterent, whatcha think? LOL :)

3) I added a third :) This category would be traffic patterns that just "are". A path up to the garage door, for instance. It's there. It's destination isn't going to change. So, don't plant a gallon shrub that's going to grow to 6' wide in the next 5 years within 2 feet of the walkway. None of use want to be stepping all over our plants or constantly hacking away at them to keep them off the path.

edited to say that some paths will require salt in the winter to keep them safe in icy conditions. Some plants cannot handle being near salt like this, others can take it better. Planning plants specifically with salt (melting piles of shoveled snow included) tolerance in mind, will cut down on plant losses due to salt exposure from paths.

This message was edited May 23, 2006 1:26 AM

I use fertilizer (sulfur types) to melt ice.

Really?! Do tell.... you mean just fertilizer granules? Like osmocote or something?

Not Osmocote, just plain old 10-10-10 that dissolves quickly and lowers the freezing temperature of the solution, just like NaCl.

OK, I gotta ask -- what the heck is Sensei? Is it some kind of hallucinogenic drug?

Guy S.

LOL -- oh! I guess I shouldn't have taken for granted that you'd catch my karate reference. Sen-say... you know, a karate master? And grasshopper is the pupil? No idea what I'm talking about? Never watched a poorly dubbed B grade martial arts film? LOL :)

So, Sensei is like the master of horticulture :)

Now maybe you'll chuckle when I sign off as,

Grasshoppa (note the accent)

Awww, hoppa, that's cute -- and clever!
(I've been called a san-seweri before . . . )

Guy S.

Any salt will lower the freezing level of H2O and I need acidity added to my soil so I add ammoioum sulfate. Works great no plant dammage and my weeds in the driveway go nuts in the spring. Hee Hee.
OK are you going to change your name again Hugga? "Som eh may" I attempt to turn any Karate movie off, Oh unless it is Jackie Chan. He is funny!
I have to ask Guy were you called that when your sewer plugged and your guests had to use the outhouse? Sans = without.

You mean y'all don't have outhouses?

Have you ever been stung in an outhouse? That is why I don't use them any more. No bees in a toilet.
I ran across another idea today in site preparation. Irrigation plans to by pass having to hire a professional. Today I ran 4 lines and had a drain on the end of each. I haven't had luck with blowing out lines here in Montana. Every year I need to replace another line. So all 4 new ones will siphon and drain to the end which on all 4 is the lowest spot.

How do y'all test for drainage problems? I read somewhere once to dig a hole and fill it wit water, let it drain and then fill it again and note how long it takes it to drain the second time. Is there anything to this? How do you know if your drainage is adequate for most plants?

This message was edited Jun 1, 2006 12:07 AM

You can do that but it is better to get an idea of soil structure. Shake up your soil in a clear "Ball" jar with 2/3 soil and the rest water you will see the structure as it sediments out. Rocks at the bottom and sand next and clay next and loam last. If you have good soil structure you will know how well it drains. Mine is (amended) 10% rocks, 10% sand-grit, 30% clay, and 50% loam (compost). The least clay the better and more sand is good too.

Thanks for the tip, Sofer. That's a neat teaching opportunity for the kiddos, too :) They love "experiments".

I say do both the drainage test and the soil structure test (use soil from the drainage hole) like Sofer said. The drainage test hole gives you the best idea if your soil (your existing soil prior to amending that is) has drainage issues which can be caused by factors you might not pick up with the jar test. The hole might show if you have a layer of compacted clay below the topsoil level which prevents good drainage for example. The jar test will let you know what you are dealing with soil wise and let you know if amendments are needed and how to amend. In Sofer's next life he'll be a worm if he has been a good boy.

I would much rather just go in the woods than an outhouse any day. The only exception is in Quetico with the relentless mosquitoes. Get that deet ready Sofer. I think I'll stop at a gas station before I visit Starhill now. Thanks for the warning.

Bill

Wise man Bill. Guy I heard has hidden electrical fencer wires to keep people out of his forest and into his outhouses.

Y'all quit pickin' on me!
I bet you didn't even know that we have electricity, sometimes, provided by the good folks at Menard Occasional Electric Co-Op!

Guy S.

I'm not at all sure about what you guys are talking about, but it's evidently rather witty ;)

I was thinking that another thing to consider when assessing a site is the positive and negative views. Positive views, of course, you want to play up -- even "frame" them with plantings. Trees and shrubs can be used to draw the eye to a pleasing view well beyond the confines of your yard. Negative views (neigbor's dog walk, tool shed, trashcans, gas meter, etc.) can be desinged around to mask or screen the space and lessen the negative impact. Paying attention to these existing positive and negative views at the outset can provide a good starting point for a master plan.

Okay, y'all. I'm almost ready to start another topic here for us. Before I do, though, let's hear whatever else you have to contribute to "Assessing Your Site" :)

Jacci

I'm still chuckliing at sofer's idea of house-hunting. "Pick a soil that is superior for the area and use the house for compost"! That would eliminate so many problems.

I disagree with him that clay is undesirable, it has great water holding capacity and high nutrient content. But too much clay is a sticky mess. On the other hand, sand is usually infertile and drains too quickly. It is a common thing to add sand to clay here. That makes good concrete, bad soil. It's better to add organic matter to break up the clay.