Garden Math

Garden Math

numbers A gardener is sometimes faced with the task of doing simple mathematical calculations, such as when measuring the square footage of a garden bed or calculating fertilizer or pesticide rates. While the mathematics involved is not difficult, it is easy to forget the individual steps if you do not practice on a regular basis.

eXtension.org logo eXtension.org, an educational partnership of more than 70 land-grant universities (including WSU), provides links to garden calculators and sites discussing garden mathematics. Some of the eXtension.org links are listed below:

Garden Hoses

What garden hose you buy should be based on the length you need and how much water you want. If you only need a 50 foot hose and not a large amount of water, then an inexpensive 1/2″ hose might do the trick. But if you need a very long hose, or a great deal of water, then a larger 3/4″ diameter hose would be a better choice.

The table below is based on information from the University of Idaho, WSU and OSO Extensions Garden Hose Flow Rate and Time Calculator. All the calculations use a supply pressure of 40 pounds per square inch (PSI), with GPM equaling gallons of water per minute.

Hose Size 50 Foot Hose GPM 100 Foot Hose GPM
1/2″ 12 GPM 6 GPM
5/8″ 22 GPM 11 GPM
3/4″ 36 GPM 18 GPM

You can see that a small increase in hose size makes a large difference in the water flow. For example, going from a 1/2″ hose to a 3/4″ hose (a 50% increase in size) triples the water flow through the same length of hose.