Pond Management-Barley Straw 

Pond algae are typically green, blue-green or brown, and free-floating. The two most common types of algae in this area are phytoplankton algae and filamentous algae. Phytoplankton algae may appear as a dense cloud in the water. Heavy blooms of phytoplankton algae can look and smell noxious. Filamentous algae are long and hair-like, and grow on the pond bottom in late winter through early summer. As water temperatures warm, oxygen and other gases collect under the filamentous mat and cause it to float to the surface, often giving it the appearance of floating moss.

Algae detract from the beauty of ponds and can discourage recreational use. In addition, the decomposition of algae uses large quantities of oxygen, which can result in fish kills. As an alternative to expensive chemical control, many pond owners have found that placing loose bundles of barley straw in their pond prevents algae blooms.

There is no scientific consensus on how barley straw works. The leading theories relate to the byproducts of released lignins as microbes break down the barley straw. Barley straw has not shown itself to have any negative effects on aquatic plants or animals.

There is no specific amount of barley to use or set frequency of use. However, below are guidelines which are intended to help those interested in utilizing this technique.

Rate: Rates are based on the size of the pond (surface area). One regular sized rectangular bale of barley straw (about 30-40 lbs.) is enough for approximately 20,000 square feet (half an acre). However, every situation is different, so it may take some experimentation to find the optimal amount of barley to use.
 

Timing of application: The barley inhibits algae reproduction, so it needs to be in the water well before a bloom starts. If the bloom has already occurred, the barley will not kill the existing algae. Early spring is the typical time for treatment, but, depending on the climate and latitude, year-round treatment may be appropriate. A rule of thumb is that if you have algae then barley straw can be applied.
 

Frequency: The best results are gained by putting fresh barley in the water one to three times per year. The most commonly used frequency is two applications. In a normal year, control can be achieved by putting barley in a pond in April or early May and then again in late summer. Here again, experimentation may be needed to determine the best frequency of application. When the barley straw begins to clearly decompose, and looks rotten, then it is time to change it. Temperature is one factor. In cold water, the straw may take 3 months or more to become effective. In warm water (70 degrees F or more), it may only take one month. Also, when putting a new bale in have some overlap time before removing the old one for continuity, as the new one will need time to begin decomposing and releasing its inhibitors.

Location: For the greatest effectiveness, the inhibitor coming from the barley needs to be circulated throughout the pond. If there is an inlet feeding the pond, then upstream down to its mouth is a good location for the barley. Not only is the water moving but it is well oxygenated. Aerators and fountains can also be used to help circulate and oxygenate the water around the barley. Alternatively, you can place the barley above the area where springs feed the pond. These may appear as areas where the pond does not freeze in the winter. If you have none of the above choices, then the barley can be divided up and placed in multiple locations around the pond. If you have prevailing winds, then place them on the sides of the pond where the winds originate.

Flotation: The barley should be placed so that it is near the surface (for oxygen and sunlight). If the water is shallow enough (one to three feet deep), the barley can just sit on the bottom. Otherwise, some type of flotation should be used. Without flotation, the bales will sink to the bottom after several days in the water. Styrofoam “noodles”, like the ones kids use in swimming pools, work well (two per bale). The noodles can be reused over and over. Plastic bottles or other makeshift items can also be used.

Preparation: The bales need to be fluffed apart, not left in a tightly bound bale, so that oxygenated water can circulate throughout the straw. Smaller sized (1”) Christmas tree netting (tubular netting) is an ideal type of netting to use to keep the straw from scattering about the pond. Other items, such as large (50 lb.) onion bags may work. One of the easiest methods of preparation is to take a 10 ft. length of Christmas tree netting and work the tube of netting over the bound bale. Next, insert styrofoam noodles into the tube of netting. Then, tie off the ends of the netting tube. Next, reach through the netting and cut the baling twine. After the twine has been cut, break and fluff the bale up as much as possible. (Note: If using plastic bottles for flotation, attach the bottles to the tied-off ends of the netting.)

Anchoring: If the barley is floating in the pond, some type of anchor (rock, block, brick, etc.) should be used to keep the barley in place. Or if the location allows, tie the bale to a stake(s) driven into the ground or run a rope to a stake placed near the shoreline.

Replacement: When it is time to replace the bale with a fresh one, pull the old bale onto shore and let it drain and dry out for a few days. Afterwards, move it to a location where it can be composted.

Alternatives: Concentrated forms of barley, such as extracts, are advertised for algae control. Seek recommendations from those who have actually used these products as skepticism may be warranted. There are chemical means for algae control that use copper in various forms. Barley straw presents itself as an attractive alternative to chemical treatments after looking at the cost, the long-term effectiveness, and considerations about the build-up of copper in your pond over time.

Give us a call and try it out!  Please give us feedback to better serve all pond owners in the future.   

(Barley straw bales being netted into "sausages" at left)

^*For a printable version of the above information please click here.