Tuesday, January 15, 2013

Garden Planning: Part 2

Welcome back to another edition of Lost In the Farmer's Market. This week the topic is about garden planning and in specific today we are talking about taking measurements. While I  admit most people do know how to use a measuring tape, there are a few things about making that information useful for planning that are not so clear. 

Before we get into details of taking measurements of your garden I do need to talk briefly about something you experienced gardeners should be doing right now aside from measuring. Whether you know it or not now is the time to take soil samples. It's winter, you've no doubt harvested some of your winter crops leaving holes in your cold season garden. Another reason to take soil samples now is because you need to know what amendments if any you need to add before planting time in April. With that said you may want to take several samples per bed, using the free UDSA soil cartons and ship them off to the testing center. The cartons can be dropped off at cooperative extension centers who will take them to the USDA soil testing labs free of charge. I might add all parts of this USDA service is free so put it to good use. Before the end of the month I will have an article up here covering in detail how to take soil samples. But enough on soil sampling and onward to taking measurements.

The second step to preparing your garden is to take your measurements right now. There are three factors to consider in regards to measuring your bed space however, the first two are length and width however height and depth can come into play.

The first thing to do is to make sure you have adequate measurement tools and a way to record what you are measuring. Generally most garden bed measurements can be handled with a basic twenty-five foot tape measure however in some cases a measuring tape reel is needed to handle distances over fifty feet. Both of these tools thankfully can be bought at any hardware store and cheaper version may even be available in the house wares or hardware sections of supermarkets and drugstores. Admittedly some gardeners due to the size of their garden beds can make due with a yard stick and thus you have to make a decision based on your individual situation.

Fortunately reading a measuring tape follows the exact same standards as reading a yard stick except for the fact there is simply more yard stick to read essentially. Some tape measures will indicate increments down to a 1/16th of an inch, but when measuring gardens it’s wiser to keep your measurements rounded to the quarter inch for mathematical purposes when calculating square footage of a bed. Don’t worry I will cover how to measure square footage of a bed later in this article.

I know for some of you using a tape measure is an easy thing, however for those readers who aren’t confident with its use, the first thing you need to learn is how to retract the measuring tape, and how to stop the movement of the measuring tape. Typically measuring tapes will come with a button or switch on the front above the tape that when raised retracts the tape and when lowered or pressed locks the tape in its current position. Also at the end of the measuring tape where it peeks out of the body there is often a metal lip which exists as much to prevent the spring inside from drawing the tape into the body as it does for the purpose of latching the tape onto a solid object and upping the tape out as you measure.  Some tape measures feature extra stuff like laser pointers, LED lights for night use and occasionally magnetic strips so the tape measure body sticks to metallic surfaces.

The Craftsman tape measure is a Self-winding type.
The above represents the two most likely types of tape measures seen average home. The model on the right is more common then the one on the left. The primary difference between both of them is that the Craftsman model has a button that allows extension and retraction of the tape. Admittedly this particular model has a spring-loaded button that you press to release the tape but other sie it's always in 'locked' position. The Stanley has no springs and is retracted by a crank on the other side of the unit. 

Generally most tape measures will use a basic annotation where each foot of distance is marked in bold while the inches are marked in visible yet smaller font for ease of reading. Beyond the two basic increments depending on the type of measure you are using the tape measure typically breaks inches into fourths, eighths and depending on the model possibly sixteenths, twenty fourths and thirty-secondths. The only people who really need the last three are contractors and professionals really so for most garden purposes it’s wasted and confusing space. I might add the typical notation of feet and inches is standardized so you don’t have to actually write feet or inches on a sketch of your beds. Feet are typically represented as something like 3’ whereas inches are notated as 3”. Now if your into precise square footage there is a way to turn inches into decimals so you can obtain precise measurements, however you have to round all fractions of an inch into fourths for it to work well.

Measuring tape styles aside, measurement of a garden bed can follow a few criteria, if a garden bed is a square or a rectangle all you have to do is measure length and width. Multiplying your length times your width will produce an accurate square footage of a bed. Square footage is typically calculated by multiplying the length of something times the width of something. So for example a six foot by four foot bed will have a square footage of 24 square feet. When you have dangling inches and your measurements end up looking something like 6’ 6” x 4” 4” which when multiplied to make square footage roughly translates to 28.145 square feet. Now I know what you are thinking; ‘how the heck did he get that stuff after the decimal?’ well the answer is an easy one the following is always true of the inches in a foot converted into decimals.

1 inch = 0.833 (has a trailing 3 decimal, so I stopped with two.)
4 inches = 0.333 (trailing decimal, remember 4” is a third of a foot)
6 inches = 0.50
8 inches = 0.666 (the mark of the beast! No seriously another trailing decimal)
10 inches = 0.833 (more trailing decimal action)

Clearly you can just multiply the 1 inch increment above to make any inch increment in between those noted above. All of these increments can be found by dividing 1 by 12 effectively making that 1 represent a foot and the 12 represent the individual inches. In the case of fractions of an inch if you will remember I said earlier that it is wiser to round these to quarters for the sake of math. The reasoning is that it is easier to convert them and it makes for a far less messy decimal when calculating square feet. For instance if we have a measurement of say 3” and 3 ¼”  we basically would treat the inch amount as if it read 1.25” and multiply that by the above listed 1” decimal conversion to get 2.708333332 which can be safely rounded to get 2.0709”.  It is still better to round to whole inch amounts with no fractions even if that means rounding down but at least the process above will guide you through if you are stuck with such a measurement.

Triangular beds are a bit trickier because what you have to do is measure the outer length and width, but not the vertical angle, then multiply length times with as if it were a rectangle, but divide the result in half. Essentially the math looks like the following.
Length X Width, result divided by 2.

Circular beds present their own issues, but where they are present, they can be measured in a unique way. The typical way to figure the area of a circle involves using Pi, no not the yummy delicious type…the boring algebra type.  If you are into that the area of a circle is simply (pi divided by 4) times diameter to the second power. Most scientific calculators can do this process rather easily. If you are like me and don’t like excessive math try this; the area of a circle will always be approximately 21.46018366 % smaller then a square where the length and width are the same as your circles diameter. So in short imagine this, you have a circle with a 3 foot diameter, imagine it as a square that is 3 feet long by 3 feet wide, then divide the square footage by 100 and then multiply it by 78.5 you have a rough approximation of the area of your circle.

My Shortcut #1: Diameter x Diameter, Result divided by 100, result x 78.5

My Shortcut #2: same as above but divide first result by 5, answer isn’t perfect but if you are counting the walls of a raised bed it may be closer to accurate then you think.

Algebra method:  Area = (pi/4) times Diameter to the second power

As a final note on measuring methods, when your talking ovals, elliptical shapes and other unusual shapes the old trick is to break them up into parts curved beds can be broken into half circles and the results of each area added up. Beds in curved terraces with undulating walls can be Ball Park measured by using the length and then multiplying by the widest widths then subtracting between 40 and 50% of the result to compensate for the non-bed curves. There is official math for this but without precise measurements and lots of use of the very much non enjoyable flavorless Pi it’s just not worth being absolutely precise.

But enough about the actual act of measurement for today now that you have an idea of how it works; we are ready for next week’s topic. In next week’s installment of Lost in the farmer’s market we will be covering methods for drawing up sketches of your garden design.

As always folks Keep 'em Growing!

No comments:

Post a Comment