University project: Tree pit watering ‘app’

[Callum McCutcheon]

Hi everyone

I just discovered this network yesterday. It looks like a great way of seeing how people from other countries go about designing urban spaces.

Hopefully people will be able to give me some opinions on a project which I’m engaged in.

I am currently in the process of developing a smart phone/computer based application as part of an arboriculture degree course which I’m studying.

The aim of the project is to develop an easy to use smart phone or computer based application which would assist people responsible for
planning or maintaining urban tree planting schemes.

As you will probably be aware the mortality rate for urban trees is very high in the first few years following planting and a lack of adequate
water supply is a major factor contributing to this problem.

The ‘app’ would allow the user to select options such as tree size, planting pit size, and soil type using pick lists. It would then link
to a climate database and give the user a 12 month watering schedule for a tree
in a particular location.

At this stage I’m looking for feedback and opinions from people involved in arboriculture and urban landscape design on the overall
‘app’ concept; features which you would like to see; how or if you currently
work out watering schedules for urban tree planting schemes, and if you would
be interested in evaluating a prototype application.

Thank you in advance

Callum

[Thomas J. Johnson]

Hi Callum,

Sounds cool but maybe a bit contrived. I’m not sure that’s how people in the field would really handle tree watering.

It seems like the tree either has irrigation (best), a watering bag, or occasional hand watering. If I had to guess, most trees die from not getting enough water because people are lazy, forgetful or the budget doesn’t take into account someone physically watering (soaking) the tree twice a week. Getting the tree in the ground is only a small part of the labor involved in it’s success. Watering by hand or water bag is labor intensive and is often overlooked.

Another problem I see a lot of is trees not planted properly. The hole needs to be 2-3 times the size of the rootball and heavily amended. The nursery soil level of the trunk needs to be maintained (ie not planted too deep or too shallow) and there needs to be a dish / lip / ring around the pit to keep water around the rootball.

Watering trees isn’t rocket science. Keep the soil moist. In most climates that requires 2-3 good soaks a week and any decent contractor will know what the watering requirements are. If they don’t, an app isn’t going to help them.

I don’t mean to rain on your parade but I just don’t see the need. If you want to design a cool “tree” app, how about one that will identify a tree based on a picture of it’s bark and/or leaf.

See a tree. Wonder what it is. Take a picture of it’s bark. App tells you what tree it is… That, I would buy… If I owned a smart phone…

[Callum McCutcheon]

Hi Thomas

Thanks for the comments.

I can see your point, and to some extent it’s all about education.

The tree itself and the way it is planted (depth, size of pit, quality of stock, formative pruning etc) definately has a big impact on the success of a planting scheme but I think most people are fairly familiar with these issues (maybe with the exception of pit size !). Watering is seen as almost an optional thing.

Your comment about cost of maintainence is also very valid, however in the UK the mortality of trees in the first two years is about 30-50% so we’re obviously doing something wrong and spending a lot on replanting.

I suppose the point I’m trying to make is that all trees need water and the amount of water varies greatly for different sizes of tree, different sizes of pit, different soil type and climate. So it makes sense to give the tree as much water as it requires but avoid watering to much which adds to the cost of maintenance.

If the app could give you an accurate figure and be very easy to use, it could allow a planner or contractor to assess the maintence cost in the planning phase so that schedules and budgets could be included in the project plan.

An effective watering schedule could lead to a higher survival rate which would reduce replanting costs. Avoiding to much or to frequent watering which is unavailible to the tree due to soil field capacity could help conserve water.

Thanks
Callum

An app which identifies trees would be the ‘holy grail’. Maybe in the future someone will invent a pocket DNA analyser , that would be cool !

[Steve Mercer]

Hi Callum,

I have a better project to turn your programing talents to. But first, 85% of the success or failure to get a tree to thrive in a new location is choosing the correct site for the tree being planted. Only 15% is due to planting practices and after care. This is not to say the this 15% is any less important that choosing a proper site. A tree can be damaged or killed if ANY of these practices are not properly executed. In the first 85%, we test the drainage conditions of the soil to determine if the type of tree being planted will be compatible with the desired site. Often times it is not. This requires a perk test. Dig a hole to the approximate size and depth of a 5 gal bucket. Fill it full of water. come back an hour later and top the hole off with water again. This assures total saturation in the surrounding soil. Time the drop of the water level from the second fill. When the water reaches the bottom of the hole the test is over. This will indicate whether the site is Dry ( hour or less to the bottom) well drained (hour and half to 3 hours) or Poor drainage (4 hours or more) You will then either have to choose another site if the tree you want to plant is incompatible with the site or choose a different type of tree that is compatible with your drainge at the site. As far as planting is concered there are some issues here as well. First assuming that the tree being planted was planted correctly at the Nursery where it is grown is probalmatic. We ALWAYS check where the flare roots are on the tree being planted. Sometimes we see as much as 6″ of extra soil on top of where the tree should have been planted. All of that extra soil has to be removed. This also causes another issue as the tree’s caliper was measured from the original ground level after you remove the soil and remeasure the tree you may find the tree now does not meet Nursery standards. A tree planted as little as a half inch to deep will reduce the life of the tree by at least 1/3! I am not a big fan of lots of soil amendments. Roots of trees grow pretty fast and they blow right by the planting pit root zone generally with-in 6 mo.s. Sooner or later the rubber has to meet the road. We do our planting pits a little differently. We plant the tree to the exact deep ( in relation to the location of the tree’s flare roots) and usually have about 6″ min of space around the ball when we plant. We cut the bottom wire and burlap off the bottom of the tree ball before easing it into the planting pit. After it is in the planting pit and has been turned to the desired direction we then stake the tree. After staking the tree we then remove all wire and burlap from the tree. Generally you can just cut the horizontal wires down the side of the ball on one side and peal the wire basket off of the ball. We then take a garden hose and turn it wide open and back fill the hole with soil slowly enough to ensure that the soil is turned to mud. This issures there are no air pockets. Plant trees like you pour concrete… air pockets are not your friend. After you are finnished with the planting pit we then go outside of the planting pit with a nursery spade and spade the surrounding soil just like you would if you were breaking a garden. Insuring that the sod (if any) is turned upside down as you spade. We will spade out at least a 1/3 wider than the planting pit. When finished we mulch the entire area. Being careful to keep the mulch at least 2 ” from the trunk of the tree. A tree that is properly sited and planted in this manner will survive and thrive after 2 waterings as long as drought conditions do not exist. The quality of the trees purchased is another factor frequently overlooked. It is difficult to look at a balled tree or a row of trees in ground and know what you are buying. Trees roots have to be pruned so that a higher concentration of roots exist in the root zone at transplant. The training of these roots begins in propagation. The propagation of trees in air pruned containers is very important as formation of good roots systems begins at radicule emergence. Growing trees in air pruned pots and preferrably later in in-ground grow bags will issure a highly fibrous root system that will in of itself impove overall success of inital tree establishment as well as longer life in in-hospitable environments such as sidewalk trees. I am including a couple of pictures of trees grown in in-ground grow bags that have been planted in root pruning pots from plant emergence. Notice the fibrous nature of the root system. Also Note the picture of the 2 oak’s on planted in a root pruned container on one not. A Big difference!

Now for your challenge. Our industry needs to create a computer program that will scientifically simulate the growth and the look of a tree in 3D see our discussion on the SketchUp forum 3d trees. http://land8lounge.com/group/sketchup/forum/topics/3d-tree-models This would benefit the whole industry. Customers could see what their landscape would look like 50 years from now the program would take into account gravity and the amount of light the plant is exposed to and reflect changes to the plant accordingly. So for example if you planted two Oak trees 10′ apart and then viewed the 3d model 40 years later, the model would show that the 2 trees had dropped branches that are growing between the trees and would be leaning away from each other. If we could get the Botanists involved and get them to supplement their botanical descriptions of trees so that we could enter that description into a program and the program would generate a scientic model that would illustrate the grow in 3d over time that would be huge.

[Callum McCutcheon]

Hi Steve

You make some very good points.

I agree totally with idea that you need good quality stock and that the species has to match the site conditions. Also that this is a better way to go than trying to artificially improve the soil conditions with amendments. Although the soil structure may be completely destroyed and amendments may be essential.

I was wondering how many of the percolation tests you do show poor drainage, and do you find that this occurs more often in city streets than in more rural sites?.

From my own experience and from what I’ve read most of the soils in urban environments suffer from poor drainage because of all the pedestrian and vehicular compaction.

This comes back to what Thomas was saying about allowing enough space in the tree pit for future root growth.
If the tree pit has enough volume to accomodate future root growth and there is a drainage system installed then poor drainage within the pit would only be a problem in heavy clay soil.

Your Sketch-up programme sounds very interesting. I’ve only just started to get into sketch-up, and i had been thinking of using it to produce 3d tree planting schemes.

My computer programming skills are very much at beginner levels. One of the things that attracted me to the Android smart phone operating system was the easy of programming. I’ll be having a look at the sketch-up forum because I think it has great potential (and it’s free)

Thanks

Callum

[Boilerplater]

Look up articles by James Urban or get his book: http://www.amazon.com/Up-Roots-James-Urban/dp/B001F93W64/ref=sr_1_9?s=books&ie=UTF8&qid=1289416916&sr=1-9
He’s done a lot of research on urban trees. In many cases, the answer is in the planting detail and soil preparation. In many parts of the US, and probably all of the UK, there is sufficient precipitation and groundwater for sustaining urban trees. Soil compaction and insufficient rooting space are more serious problems, as others have indicated.

[Steve Mercer]

Hi Callum,

The soil drainage is an issue that is particular to specific areas. Obviously soil types vary even in farmland. In our city (Louisville, Kentucky USA, We are a rivertown and sit right on the Banks of the mighty Ohio River. Areas close to the river and much of downtown Louisville is sitting on sand. Drainage is excellent there. However in the south part of the city those areas were originally a swamp and it was not at all uncommon to find places where the water was either a couple inches above grade or at grade year round. Even though the city has dug huge drainage ditches to drain away the water the compacted soil remains an issue. In other parts of the city we see heavy clay and lots of rock. So it does vary depending on where you are. We routinely (40-50% of the time find that the tree picked for a site is not compatible with the drainage of the site. As to the issue of Street trees surrounded by concrete. Soil volume will always be an issue. However, having said that ,Planting trees in that environment with a well developed Fibrous Root System will enable those trees to exist in that harsh environment longer. You will find that Sketch-up is not exactly Free. In order to use it in a production environment you will have to be able to import and export AutoCad files .dxf and .dwg. This can only be accomplished with the Pro version of SketchUP. If you are interested in using SketchUp Daniel Tal’s book “Google SketchUp for Site Design: A Guide to Modeling Site Plans, Terrain and Architecture.” is an absolute must read. He is also on the SketchUp Group and is approachable if you get stuck on something. He also performs regular paid webinars that are very informative and well worth the money spent. Our operational platform of choice is Windows Mobile. Right now Microsoft is in a transition as they roll out their WM 7 OS. For an example I use a Motorola MC 75. It has Microsoft Office already installed. We use a product from Exaktime to keep time of our mobile work crews called Pocketclock GPS. It allows the foreman who carries the device to clock whole crews in and records the exact gps location of where the crew clocked in at. It records the employee time by job. So jobcosting is a breeze. I also use a Software product called SurvCE by Carlson software. This software package interfaces to my Leica 1105 Robotic Total Station. I use FieldHawk radios between the robot and my MC75. the radiios communicate with my MC 75 via BlueTooth. We also have a Line busting application for our Garden Center that allows us to walk up to a customer anywhere in the garden center and quickly scan all the items they wish to purchase with the MC75’s Barcode scanner. when scanning of the items is complete we save the invoice as an invoice on hold on our server via a WiFi Hotspot and at the same time print a barcode ticket on a portable battery operated BlueTooth reciept printer clipped to your belt. The operater then hands the receipt to the customer and points them to the check booth for check out. The operator at checkout merely scans the barcode on the reciept and it calls that invoice up from hold off of our server. The pos operator then collects customer info collects the money and prints the receipt. We also have a driveway alert system that sends a broadcast text message everytime someone enters our property. We have webcams on the parking lot so we can view who comes in from the MC75 and determine if a customer needs to be greeted. Mobile Excel has become enormously useful.

s.

[Callum McCutcheon]

Hi Boilerplater

Thanks for the book recomendation.That looks like one for the christmas list (counting down the days!).

I would agree that there is sufficient precipitation in most parts, but how much of that is actually available to the tree?. Compared to uncompacted loamy soil, the water infiltration rate through asphalt is zero, paving stones and paving bricks only 5-10% and even the best semi permeable asphalt only 50%.

Much of the water is diverted away through drains, and compacted urban soils often have low holding capacity. At the same time urban trees are subjected to higher temperatures, lower humidity, and increased wind speeds compared to a rural environment.

Once a tree is well established then it is able to cope as long as the tree pit has enough soil volume, but in the first 2 or 3 years following transplantation then suplementary watering to the root zone during the growing season is very beneficial.

Callum

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