Community Garden Irrigation

Water is always at the top of a gardener’s list of concerns, but with drought and heat unusual to Vermont’s gardening season the question of how to get enough water to thirsty plants has been particularly salient. Old systems that gardens put up with in milder years are no longer cutting it. Community gardeners have been calling with questions about more efficient systems to make things easier for both the plants needing water and the people charged with caring for them. Here are some systems to explore, including some tips from the field.

Many community garden sites are faced with the challenge of finding easy access to water. In this case, here are some ways to get the water you need to your site:

Bury It

If your spigot is a distance from your garden that means loads of hose hauling or if there are above-ground obstacles between your spigot and garden, an excellent solution is to bury a water line and bring it aboveground in your garden. Here are instructions for a more permanent solution where you won’t have to drain the line each fall. You just have to have the equipment and a little know-how to pull it off. Check your area’s frost depth to determine how deep to bury your line. 

However, many gardens can get by just fine with the more simple solution of burying the length of a hose, typically 3-6 inches deep, and draining and disconnecting the line from the source each season to avoid freezing. Considerations: hose sturdiness to withstand potential critters and freezing, and ground conditions for digging a straight path to your garden. This article provides some tips and video instructions. 

Catch the rain

Rainwater catchment (i.e. rain barrel, cistern) is an excellent way to harness this resource already coming to your site. In this scenario, your garden will need a structure to which you can attach a gutter, drainpipe and catchment barrel. Typically, based on the size of structures located at garden sites, these water catchment systems are more supplemental than serving as the primary water for the site. However, at some gardens, like Riverside Community Garden in Burlington (pictured here), gardeners have come up with creative infrastructure designs that allow for the capture of significant amounts of rainwater. Calculate how many gallons you can collect based on your roof size. You can purchase a rain barrel kit at many garden, farm and yard supply stores (here’s a short-list of Vermont-based locations). The Vermont Department of Environmental Conservation periodically runs workshops on rain barrel building and sometimes offers rain barrels at reduced prices. But you can also find your barrel for free. Check with food processing plants, animal supply outlets, and dairy farms to see if they have barrels to give away. Keep an eye on garage sales and Craigslist, and even consider putting a request out on Front Porch Forum. Tip: If you plan on using rainwater for any type of food plants or herbs, be sure that you use food grade barrels. And no matter what–be sure the barrel has never held any toxic materials. Also, here are DIY instructions for building your own rain barrel system out of a garbage can or 55 gallon food grade barrel. More on cistern installation and capacity can be found in this guide developed by the Vermont Department of Environmental Conservation.

Fill ‘er up

• 

• 

For gardens where no water is available on site, oftentimes the solution is to purchase a water tank that gets filled regularly. These tanks make gardens possible in places where otherwise they would not be able to survive. The watering system at the NVRH Community Garden in St. Johnsbury includes a 550 gallon tank with a spout, set on a hay wagon. Mary Maurer, Garden Coordinator, relates that the maintenance team at the hospital (where the garden is located) fills the tank on average twice a week and more frequently when it is hot and dry. They hitch the wagon to a tractor to bring it to and from the water source–a two-hour job start to finish each time. The 550 gallon tank provides water for 28 garden plots, an average of 25 x 30 feet each, moving around the garden to different locations (so easy water access is equally distributed) after each filling with a tractor. The gardeners then water their own gardens with watering cans. A tip from Mary: Make sure that your wagon has a good turning radius and that you design your garden so that you have room for the wagon and tractor to move between the garden plots.

Harness the river

• 

• 

Gardens located near a river can harness this water source by using a pump that brings water up the bank and into the garden, as opposed to the back-breaking work of hauling it by hand in buckets. A hand pump is most typically used, which can also be a time-consuming and physically demanding task, but is do-able for watering smaller plots. Billings Farm Community Garden in Woodstock has experimented with several different pump solutions. Their hand pump system serves as a steady back-up, but they are currently exploring two other systems: a solar pump system and a ram pump system. Linda Galvo, Garden Coordinator, has the following tips to share:

• Solar pump systems can be very expensive (in the case of Billings Farm, thousands of dollars have gone into two solar pumps). With this in mind, Linda emphasizes that anyone who wants to do this needs an expert in water pumps. For the solar components it should be easy to find someone who can put a solar array together. Find a pump that has a listed capacity for how far it can move water that matches your set-up. Similarly consider the type of pump you use and how much it can handle particulates. For example, if you are pulling from a shallow brook that has plenty of sand and silt you will want to avoid a pump that only functions with pristine water with no particulates.
• A ram pump is an older, but very effective technology where the pump is placed in the river or next to it and pushes the water, which is ultimately easier on the pump (as opposed to pulling water vertically, 20 feet, in the case of the Billings Farm Community Garden). No electricity or solar power are needed to run a ram pump. You can purchase one from $75-$175 or about $50 in parts. Here’s a great website all about ram pumps.

Let gravity do the work

• 

• 

Gravity-fed irrigation systems draw water from a reservoir (i.e. pond, tank) located uphill from the garden and, through pipes, allow gravity to pull water to the garden. The gardeners at Barton Community Giving Garden use a combined rainwater harvesting and gravity-fed system. Their water source is the public library roof located just uphill from the garden. A cistern collects water via the downspout and a hose runs down the hill to a smaller blue barrel. The system not only uses their advantage of bank elevation, but the tank at the top of the hill helps provide pressure. The garden team primarily uses a hose that connects to the blue barrel for watering the garden. However, garden team member, Cindy Delano, reflects that one improvement would be to have the blue barrel mounted higher so that a watering can could easily fit under the spout; particularly useful when watering seeds.

Once you have water at our site, how will you water? Here are some types of irrigation systems to consider:

• Watering by hand with a watering can or a hose is probably the most common watering method for community gardens. It is cheap and typically easy to use and is the best system to use when watering needs vary throughout the garden, like when the garden is divided into plots managed by different individuals or families. Watering cans are also a fun activity to involve kids in gardening. If using a hose with a spray nozzle, try to avoid spraying the whole garden at once, but focus on individual beds and plants, so that you are not also watering pathways, etc. For more efficient watering, consider creating a furrow near the individual plant or row and fill it with water. And whenever possible, water the soil, not the plants themselves, and in the morning, to avoid water-borne diseases.
• Overhead irrigation (a.k.a sprinklers) can be useful for gardens that are collectively managed, watering one large space at once. Sprinklers remove the task of hauling hose around the garden and also bring automation to the often time-consuming task of watering. You can let it run for a designated period of time and even add a timer to it for when you aren’t able to visit the garden. Similar to overhead hand watering, sprinklers can waste lots of water by watering pathways and watering must also take place in the morning so the leaves can dry before evening. There is also potential for wind drift and evaporation to happen before the water gets to the root zone.
• Soaker hoses are yet an even more efficient way to water your garden. Another system that will work best for collective growing spaces, rather than individualized plots. This system involves simple set up of low-flow hoses around plants and along your garden rows. What makes these so efficient and effective is that they slowly leak water into the soil directly around plant roots, rather than broadcasting it. These systems work best when used on flat ground and under plastic mulch used around warm season crops. You can purchase soaker hoses or use recycled materials. Here are DIY instructions for making a soaker hose out of a regular garden hose. Note: Soaker hoses typically only last a few years before wearing out. Also, if you are watering multiple areas in your garden at once it can be difficult to get the pressure you need.
• Drip irrigation is the most efficient of all of the basic irrigation systems. It is similar to soaker hoses in that you’ll be focusing the placement of water near the plant roots, but is even more precise, with holes spaced along with plantings. These systems are best for large growing spaces and do not do as well in soils that easily dry out, like raised beds. Two drip irrigation methods are 1) to attach the system to your on-site spigot or 2) if a water line is not present in the garden, feed the system with an elevated bucket. A classic drip irrigation system can be more expensive than other watering systems, simply due to the many parts to set up and maintain. Bucket drip irrigation can be achieved through use of recycled materials  Here are DIY instructions for bucket drip irrigation. Drip irrigation, like soaker hoses, functions best when placed under black plastic mulch.

Mulch, Mulch, Mulch! Whatever system you’re using will be made more effective and efficient by keeping your garden beds covered in mulch–keeping beds moist and suppressing weeds that would compete for water. Straw is a favorite, but you can also use bark mulch, untreated grass clippings, black plastic, as well as many other mulches. If using plastic mulch, consider running a soaker hose or drip irrigation system underneath to keep your plant roots moist. 

• 

•