La Message Board Archives

Community garden- being water wise

Posted by Rick (Lyle's Dad) on June 15, 2012, 3:12 pm

1. How much water do my vegetable plants need?

Without being too scientific about the water needs of various crops, and they do vary, it is a general rule to assume that your plants will need about 1-inch of water per week. If this is not sufficient, in general, the plants will let you know. This may be a bit shy for peas, corn and potatoes but we usually only have peas.

The plants that are common to the community garden will need water at least every 3rd day and possibly every 2nd day given our intense conditions. The plants can not survive on 1-inch of water per week if it is given at 1 time and they are asked to make it through a week. So, how does 1-inch of water per week translate to time holding the hose at your plot?

The average plot size in the community garden is about 65 sq. ft. Some are a bit more, some are a bit less. You can verify your size if you wish. Some are in full sun for most of the day, some are not. 1-inch of water over an area of 65 sq. ft. is equal to 5.4 cubic feet of water. This translates to 40.5 gallons. To be safe, letís just say an even 45.0 gallons of water a week on an average size plot will result in 1-inch of water.

I made tests of 4 different water stands out in the garden to determine their flow rates in gallons per minute. Of course there are variables that affect the flow rates such as; number of people using the system, the amount of water in the storage tank and so forth. I also made a test of the public water supply stand. For the public water supply stand, the flow rate varies depending on the pressure that Morgan has put into the system. Iíve determined that the average flow rate for any source in the community garden is approximately 1.4 gallons per minute. So, here is the answer to the question of how long you have to hold the hose in order to place 1-inch of water on the average size plot.

32.1 minutes @ 1 time per week (not suggested)
13.8 minutes @ every 3rd day or 7 times each 3 week period
9.2 minutes @ every 2nd day or 7 times each 2 week period
4.6 minutes @ every day (generally not suggested)

The 1 time per week watering is not suggested because the plants will dry out between waterings. The every day schedule is not generally suggested because this type of watering will not be a deep watering and will not force the plantís roots deeper into the soil, which is beneficial. With that all said, new lettuce or arugula shoots can dry out very quickly as they are not deep rooted crops at any part of their lives. Thus, they are the exceptions to this suggestion of not watering every day. There are always exceptions.

To conclude, if you come every 2nd day and watered your plot for 10 minutes each time, you should be fine. If you come every 3rd day and watered your plot for 14 minutes each time, you should be fine.

2. Watering in harmony.

Weíve let everyone know, or if not, we are letting you know now that the public water system is not on in our area for the same amount of time as other areas of town. Often our water is only on for an average of 3-4 hours per day, Monday through Friday, perhaps 3 hours on Saturday and it is rare to be on at all on Sunday. That all said, in a typical 7-day week, we will generally only have public water supply for 20 hours a week. In general, when the public water supply is on, it is usually on around 9:00 a.m. and off by 1:00 p.m.

Thus, this is the reason why we have the water storage tank in the garden. The water storage tank holds 1,100 liters (290 gallons) when it is full. The water storage tank can only re-fill or re-charge when the public water system is on and operational.

With all this said, we understand that any particular gardenerís watering schedule has to work with their personal schedule here in La Manzanilla. We realize that. But, it goes without saying that is should be obvious that if we can water the plots in the mornings, during the times when it is reasonable to assume that the public water system is on, it would be to everyoneís advantage to do so. There are several water stands out in the garden. In the past years, I have not seen a situation where more than 3 parties have been watering plots at the same time. Just so you know, there are 31 total plots.

Under no circumstances should you start watering a plot, either with the water storage tank or the public water supply tank, and then leave the community garden. In the past, there have been many, many instances where the storage tank has run dry because a hose was left on. Worse yet, it can be on a Saturday morning which then means that there will be no water at all until Monday, leaving perhaps Ĺ of Saturday and all of Sunday totally dry.

Other watering comments:

 It bears repeating that if the public water system is operational, the storage tank re-charges fairly quickly. A full water tank can empty in about 3 hours from 1 hose.
 Watering in the morning hours reduces evaporation loss during watering.
 Watering after sundown is just what the bugs want you to do. They are out at night and would thank you in person if they could. Plants can suffer.
 If you can mulch around your plants, this reduces evaporation loss. Mulch might be in the form of; bamboo leaves, straw, fallen leaves, or grass clippings.
 Wood chips, from the carpenterís shop, can be a beneficial mulch but it is suggested to use only chips that are from primavera or pine woods. Do not use chips from woods that are treated with resin, paint or the like. In my opinion, dark red colored chips from Perota or Rosa Morada are aromatic. Those types of chips are great for the garden paths, but I think they should not be used in vegetable gardens. The chemical source of their scents could be detrimental to good microbes in the soil, in my opinion. Simply asking Philippe (the carpenter) or Pancho (his dad) what type of wood the chips are from is a simple task. If you happen to get the aromatic wood chips, donít worry, Iíll use them somewhere.
 Watering closer to the ground reduces evaporation loss and also reduces the threat of making the leaves wet which adds to the potential of damage due to a number of different ways.

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