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Home  > Question of the Week

Question of the Week

Permalink Should I filter water from a rainwater catchment system if it's used to irrigate vegetables?

Answer: There are several factors that can affect the quality of water harvested off a roof, including the type of roofing material and environmental and climatic conditions. These factors can contribute to water contamination and may affect how the collected water is used. While many rainwater collection systems are designed for drinking water, water tests have shown that high levels of bacteria, heavy metals (primarily zinc, lead, chromium, and arsenic), and polyaromatic hydrocarbons can affect plant health from water that is collected and used to irrigate plants. In addition, many roofs are treated to resist algae, moss, and lichen and these chemicals can be toxic. It is also important to note that flashing, such as around a skylight or vent, can leach lead in to the water.

There are many types of filtering devices that are used in purifying harvested rainwater, from gutter guards and debris traps to advanced filtration systems. Some systems are even designed to divert the first flush of harvested water away from the catchment system. Studies have shown that as much as 80% of contaminates from the roof or gutter can be diverted in a first flush. That said, several factors, such as the type and slope of the roof, amount of rainfall, and amount of debris, must be considered in determining how much water to divert.

One technology worth considering is a slow sand filter. This filter is designed for small-scale systems and test results from the past five years have shown that it is producing safe levels of drinking water. For more information, visit

For more specific information on filtering rainwater from roofs, consult the following resources.

Kinkade-Levario, Heather. 2009. Design for Water: Rainwater Harvesting, Stormwater Catchment & Alternative Water Use. Gabriola Island, BC. New Society Publishers.

Lancester, Brad. 2005. Rainwater Harvesting for Drylands and Beyond, Vol.1: Guiding Principles. Tucson, AZ. Rainsource Press.

Lancester, Brad. 2012. Rainwater Harvesting for Drylands and Beyond, Vol.3: Roof Catchment and Cistern Systems. Tucson, AZ. Rainsource Press.

Ludwig, Art. 2005. Water Storage: Tanks, Cisterns, Aquifers, and Ponds. Santa Barbara, CA. Oasis Design.

Websites – website of author mentioned above, Brad Lancester. Contains information and resources on rainwater collection. – the American Rainwater Catchment System Association. Promotes rainwater catchment systems in the U.S. Contains information on rainwater catchment, suppliers, and additional resources. – NSF International. Organization supports standards for safe food, water, and consumer goods. Contains consumer information on rainwater collection. - online community and resources that supports sustainable water management.

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Permalink What raspberry and blackberry cultivars do you recommend in Oklahoma and Arkansas?

Answer: First, it's difficult to recommend any raspberry varieties for that area. The OSU Extension's Blackberry and Raspberry Culture for the Home Garden, available at, recommends against planting raspberries. Oklahoma and Arkansas have always been at the southern limit of raspberry adaptation, and these last few summers have made that even more so.

With that said, ‘Heritage’ raspberries will grow by giving them partial shade and some cooling overhead irrigation on the hottest days when they have fruit. Research shows that just 30 minute sprinkle irrigation in the hottest part of the day will greatly improve yields and eliminate "crumbly berry."

Also, you will occasionally hear someone recommend 'Dormanred' raspberry for the South. 'Dormanred' is technically a raspberry but lacks the musky flavor of most popular raspberry varieties.

Blackberries are easier. The series of blackberries from the University of Arkansas (mostly from breeder Dr. James N. Moore) are recommended for almost all of Oklahoma. Here are the descriptions from the OSU bulletin:

Arapaho—an erect, thornless blackberry. The fruit are medium-sized, firm, and have excellent flavor, ripening about two weeks earlier than Navaho. Arapaho was released in 1993. The fruit flavor is superior to semi-erect thornless blackberries. Since Arapaho has not been widely planted, its disease resistance is not thoroughly tested.

Cherokee—an erect, thorned blackberry. The fruit are large and firm, with excellent flavor, ripening in mid-season. Root cuttings are readily successful as a propagation method. A disease control program is recommended.

Cheyenne—an erect, thorned blackberry. The fruit are very large throughout the season. The flavor is slightly better than Comanche but not as good as Cherokee. Cheyenne has smaller seeds than Cherokee. The fruit ripen in mid-season, slightly earlier than Cherokee. Root cuttings are readily successful as a propagation method. This variety is moderately tolerant to anthracnose, but a disease control program is recommended.

Choctaw—an erect, thorned blackberry. The fruit are medium-sized and firm, with small seeds. They have better flavor than Cheyenne and Shawnee. Fruit ripen early in the season, about nine days before Cherokee. Root cuttings are readily successful for propagation. This variety is moderately resistant to anthracnose but is occasionally attacked by powdery mildew. It is known to be hardy to -14° F in Arkansas.

Navaho—an erect, thornless blackberry. The fruit are large and firm and are less tart than other thornless varieties. They ripen late in the season, about 12 days after Cherokee. This variety is moderately resistant to anthracnose and is known to be hardy to -14° F in Arkansas. This is a higher quality blackberry than almost any before it.

For more information on bramble fruits, see ATTRA publication Organic Culture of Bramble Fruits at This publication focuses on organic production practices for blackberry and raspberry production. Included are discussions of site selection and preparation; fertility; weed, disease, and insect management; greenhouse production of raspberries; and economics and marketing.

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Permalink Can I graze chickens in my orchard without compromising food safety in the fruit?

Answer: Grazing chickens in orchards is mutually beneficial to the birds and for fruit production. Orchards provide shade and food, while chickens control pests, insects, and weeds; eat dropped fruit, which prevents fungus and insect infestations; and also provide fertilizer.

The USDA National Organic Program regulations require 90 days between fresh manure applications and harvest to be in compliance with USDA organic certification, so grazing should be complete 90 days prior to harvest.

For more information on food safety on the farm, see the ATTRA publication An Illustrated Guide to Growing Safe Produce on Your Farm at This publication discusses ways farmers can reduce produce contamination risk, which creates a safer food system and increases consumer confidence in their own products and farm at the same time.

For more information on pastured poultry, see the ATTRA publication Alternative Poultry Systems and Outdoor Access at This publication discusses differences between alternative and conventional production systems. Various aspects of free-range systems in the U.S. and abroad are presented. Common poultry housing approaches are also discussed, as well as integrating poultry production with vegetable production or livestock grazing. Considerations related to organic poultry production are presented. Production topics such as outdoor access, pasture management, and predator control are also addressed.

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Permalink I want to buy farmland. What should I consider?

Answer: There are several things to consider in your search for farmland. A thoughtful and thorough search and planning process will increase your odds of finding the right property for your unique goals.

Some important questions to ask yourself that relate to what land arrangement will work best for you include:

1) What do you plan to grow? You need less land, but higher-quality soil, if you plan to grow vegetables as opposed to large ruminants like cattle, for instance.
2) Where are your markets and how far are you willing to drive?
3) Do you have a partner or family member with an off-farm job (or will you need an off-farm job), and where does your land need to be in relation to those jobs?
4) Do you need housing and is there housing on or near the land?
5) What water resources are available for irrigation or livestock?
6) Have you weighed the benefits of renting vs. buying farmland?

A very good website on the topic of acquiring farmland is Land for Good at This resource offers an online tutorial to guide farmers through the process of finding and evaluating farmland. Another great online tutorial is available from Cornell University's Northeast Beginning Farmers Project at

For more information on renting farmland, see the ATTRA publication Finding Land to Farm: Six Ways to Secure Farmland at This publication highlights some common ways to lease or own land. It outlines important considerations about each of these leasing options and paths to ownership.

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Permalink What’s the best way to control cheatgrass in my pasture, using goats or flame weeding?

Answer: Cheatgrass is an aggressive annual grass that germinates in late winter or early spring. It’s best to use and repeat control techniques early in the season before flowering and seeding. Grazing and flame weeding can be used in conjunction or individually depending on your circumstances.

Cows, sheep, and goats will eat cheatgrass. Grazers prefer to eat the younger plants but can be encouraged with sweetness by spraying the pasture with a water and molasses solution.

According to an article published by the University of Idaho’s Rangeland Ecology and Management program,, targeted grazing is an effective tool to control cheatgrass using heavy, repeated grazing for two or more years. This treatment method reduces plant density, size, and seed production. The article also notes that grazing should be closely monitored to avoid damage to desirable perennial plant species.

Flame weeding, a thermal weed control, uses propane gas burners to produce a carefully controlled and directed flame that briefly passes over weeds, searing the leaves and causing the weed to wilt and die. Flame weeding, as a non-chemical weed management technique, is frequently used by organic farmers.

Weeds are most susceptible to flame weeding when they are seedlings, one or two inches tall. Broadleaf weeds are more susceptible to lethal flaming than grasses. Grasses develop a protective sheath by the time they are approximately one inch tall and may require a second flaming. Repeated flaming can likewise be used to suppress perennial weeds such as field bindweed.

Flame weeding in pasture should be used with caution depending on the time of year or moisture and temperature so that the flames can be easily contained.

For more information on grazing and pasture management, see ATTRA publication Pastures: Sustainable Management at This publication addresses numerous aspects of sustainable pasture integration, grazing rotation strategies, and management options. It covers grazing systems, pasture fertility, changes in the plant community through grazing, weed control, and pasture maintenance. It also discusses planning and goal-setting and offers an appendix item on trees in pasture settings.

For more information on flame weeding, see the ATTRA publication Flame Weeding for Vegetable Crops at This publication discusses different strategies for pre-emergent flame weeding and post-emergent flame weeding, as well as infrared weed control and steam and hot water weed control. Further references, including sources of information and equipment, are also provided.

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