That Hugelkultur Thing

Oh yes, I’m going to be talking a lot about hugelkultur beds because we just finished our first small 10′ section of it this afternoon. While it didn’t take very long to do, it was a lot of heavy lifting. Most of the work was actually clearing out the bed of raspberries (that never have produced a single berry) and weeds and then digging a foot of dirt out.

Building a hugelkultur bed doesn’t actually require you to dig up the dirt and sink it, but what can I say? We’re gluttons for punishment? No, actually, our soil has been so nicely amended and had this great texture that we decided to dig it out so we can add it back to the top of the hugelkultur bed. And in the past when we used to do raised beds we always found that when we included native soil in the beds they always did a lot better. My guess is that the native soil includes micronutrients and microorganisms that compost doesn’t have.

We then laid down sheets of cardboard. Of course, this is another step you don’t have to do but because we have such a problem with bindweed (which can have viable roots as far down as 20′) we decided that putting down cardboard would create a barrier to help stop the bindweed but eventually break down once it was no longer needed. Once the cardboard was down we started tossing wood of various sizes onto the pile. and a few old artichoke stalks for good measure. The wood is the key to hugelkultur. While it breaks down over time it will absorb water like a sponge while also releasing nutrients. The water absorption helps reduce your water use. If you make large 6′ tall beds you can go without adding any additional water during dry summers. Since our bed is not that high we’ll still have to supplement with summer water but we can definitely cut back since a bed that’s only 2′ tall can hold water for approximately 3 weeks. This leads to another important thing about these beds. You have to build them before the rains come, which is late fall here, so they can absorb as much water as possible before you can plant them. It’s best to use rotting wood which will hold more water and is also less likely to tie up nitrogen in the soil. Also avoid certain woods such as black walnut, cedar, redwood, black locust and eucalyptus which either contain rotting inhibitors or contain compounds that are toxic to other plants. Fruit tree wood also has a tendency to be too hard and take too long to start rotting.

After we got all the wood in place we placed a good thick layer of poultry litter which consists of straw with chicken and turkey manure and quite a few feathers (just because they are currently molting). Poultry litter is the best way we’ve found to get a compost pile up and running quickly so we wanted to use this directly on the logs to help get the breakdown process started. Again, this isn’t necessarily a step you must do to build a traditional hugelkultur bed, it’s just a step we chose to do.

Another step we chose to include was to cover the poultry litter with finished compost that we picked up at the local recycling/composting facility. $4.31 for a truckload, which you just can’t beat.

The final layer, which is really the only other thing you have to do besides using wood, is covering the bed with soil and smoothing it out. Yes, it’s a lot of work but the work we do now means we won’t have to work later. Hugelkultur beds are kind of self-tilling and since they are raised they’ll never get walked on, which compacts the soil. We’ll definitely finish off this one bed, hopefully getting more of it done tomorrow and then we can start thinking about doing some of the other larger beds. Eventually if this works out for us, I’d like to do all of our beds this way.

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How to Install Irrigation

Here comes the real fun part about putting in irrigation. The calculations! Doing these calculations is key in determining zones, how many times you water per week and for how long.

The first thing you want to do is create zones for each basic type of plant. For us we have a zone for fruit trees, a zone for our drought tolerant landscape, and 2 zones for our vegetable garden. We are using Rainbird Xerigation Control Zone Kit ASVF-LF-075 for each of our zones. We are also using 3/4″ SCH40 pipe. I generally don’t recommend using smaller pipe because you get better pressure with larger pipe and it’s not that much more expensive. Generally with drip you won’t need to go above 3/4″ pipe.

Now what you want to do is determine your gallons per minute (GPM) from your water lines. The easiest “low tech” way to do this is with a timer and a 5 gallon bucket. Turn your water spigot on full blast and then right when you put the bucket under it start your timer. Stop the timer when the bucket is filled. Divide the 5 gallons by the time in minutes to find the flow rate. If it takes 30 seconds to fill the bucket then your water is running at 10 GPM. Or 5 gallons/.5 minutes. If it takes 45 seconds then your water is 5 gallons/.75 minutes = 6.7 GPM. However, if you are using a drip system valve and pressure regulator, it will bring your flow rate down to 5 GPM. You just want to make sure that your household flow exceeds the top flow allowed by the valve.

Next you want to figure out which type of irrigation system you want to use. We are going to assume that you will be running a drip system at 5 GPM. Manufacturers will have this information with their products as it can be slightly different than what I list. The information I’m giving is just a general guideline. If you use drip emitters each emitter will have specified rate, such as 1/2 gallon per hour (GPH). So 120 emitters would equal 1 GPM. (60 min/.5 gallons per hour = 120 emitters) You can run 600 – 1/2 GPH emitters per valve. T-tape runs at 40 GPH per 100′ or .67 GPM. However, runs of T-tape should not exceed 350′, which is why we have to have two control zones. 1/2″ soaker hose runs at 54 GPH or .9 GPM per 100′ so you cannot exceed 450 feet of run per zone. Bubblers, which we use on our trees run at 13 GPH or .22 GPM. We can run 22 bubblers on that zone.

Scheduling (how often for how long to apply water) is more difficult to determine because it is dependent on so many factors such as heat, precipitation, humidity and evapotranspiration. And each of those factors are different depending on where you live. The easiest way around this is to get a Smart Controller that has a subscription to weather data and will turn on as needed. If you don’t want to spend the extra on a Smart Controller you can refer to the chart on this site for basic scheduling: http://www.dripdepot.com/article/determining-drip-irrigation-watering-schedule

Hopefully I didn’t lose you. If you have any questions or need help doing zones just let me know and I’ll be happy to help you out. For non-drip areas the zoning gets much more complicated and would be too much to discuss on this blog.

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Irrigation Supplies: The Basics

If you’ve decided to put in irrigation for your garden there are quite a few things you will need. Some are obvious like a water source, irrigation line, etc. However, the trick is figuring out what types of things do you need? Well a lot of it depends on the type of irrigation you are using. Because we focus on vegetable gardening on this blog, we’re also going to focus on the best way to water a vegetable garden. Most likely you will want to you use drip. There are several different types of drip line and they all have their benefits and disadvantages.

1. Piping & Tubing:There are several types of piping and tubing. The most popular piping is the white PVC hard pipe. This pipe is for underground use. UV rays from the sun will break it down so it’s not recommended to be above ground. I usually specify Schedule 40 (SCH 40) pipe, which denotes the wall thickness. It’s the standard pipe you can find at just about any hardware store. It does come in different sizes, 1/2″ being the smallest. Tomorrow I’ll go over how to size your pipe if you do decide to use it. Risers that come out of the ground off of the buried pipe are usually gray. They contain carbon in them to help keep them from degrading.

There are different types of connectors. Some connectors are threaded. When putting together threaded connectors always wrap teflon plumbers tape three times in the direction of the threads. This helps lubricate and seal the connection. For slip joints you want to use a primer and chemical solvent or pipe cement. Primer is very important for any lines that will hold pressure. There is a solvent you can use that doesn’t need primer called Christy’s Red Hot Blue Glue. Techinically it’s not a glue, but it’s a catchy name.

 

1/2″ Poly Tubing
Double Barbed
Connector

There is also 1/2″ and 1/4″ poly tubing. This is a flexible black tubing that comes in rolls. This should be used above ground (but it can be hidden under mulch). This you will generally use to reach plants. Barbed connectors are put into this using a punch specifically designed for this tubing. This can be either pressure compensating drippers (see #2) or double barbed connectors. The double barbed connectors connect 1/4″ tubing into the 1/2″ tubing. There are also T Connectors, Elbow connectors, and Compression Couplers to help you design your irrigation system.

Soaker Hose

Emitter Tubing

Three additional types of tubing are soaker hose tubing, T-Tape and emitter tubing. Soaker hose is a porous flexible black tubing that drips water over it’s entire length. It’s not recommended if you have hard water though, as the pores can easily get clogged. T-Tape is a flat hose that has slits on the bottom at specified intervals. When water enters the tape it expands into a tube, a flap on the underside opens up and the slits drip water. This one is good for long, straight runs. It cannot be used on curves though. It is also the least expensive of most drip systems and what we use in our garden. Emitter tubing, which is by far the most expensive, contains inline emitters at specified intervals. The soaker hose and emitter tubing can be connected to 1/2″ poly tubing with compression fittings (for 1/2″ lines) or barbedconnectors (for 1/4″ lines). T-tape requires it’s own specific fittings to connect to poly tubing.

It’s also important to note that fittings from one manufacturer of tubing won’t necessarily fit other manufacturer’s tubing. For example, we purchased 1/2″ tubing from an online farm supply store. It turns out that the outside diameter is greater than 1/2″ so the fittings at the hardware store don’t fit it, which are the most convienent fittings for us to purchase.

 

Pressure
Compensating
Dripper
In-line Dripper

2. Drip Emitters: These are usually little button drippers. They have pressure compensating drippers (note that one end is barbed and one is smooth) that can be inserted right into 1/2″ poly tubing and will drip at a given rate – usually 1/2 - 2 GPH. There are also in-line drippers that have two barbed ends. These must be inserted into 1/4″ poly tubing. There are also what’s called bubblers that can be inserted into 1/2″ poly tubing. These release a lot more water and need a lot more pressure to work well so you cannot run a long line of them. I only use bubblers on my fruit trees, which need more water than a normal drip emitter can supply.

3. Controller Valves & Associated Accessories: The controller and valves are the most important part of an irrigation system. These are what controls the water in your garden. You can go with a simple pneumatic controller with a hand turned compression valve, or you can get fancy with a 6 station automatic controller with automatic valves. We used the simple version last year but are currently converting our system for the fancier version.

A pneumatic controller is similar to a kitchen timer. You just turn the dial to the time you want the irrigation to run. When time runs out it shuts off.  You use it with the compression valves, which you have to turn by hand for what beds you want to run. With this type of set up you have to be available.

The best, and of course, most expensive controllers on the market are the “Smart” controllers. They are usually synced to either your own small, personal “weather station” or a satellite which tells it the precipitation, and evapotranspiration of your plants for the current weather and then runs accordingly. This type usually requires a monthly or yearly subscription.

The automatic controller has days and hours in it so you can program it to go on certain days for a given time. A “set it and forget it” type of controller. This controller operates the valves to turn on and off. There are also battery operated valves that are a similar idea. However, I don’t recommend these because they are not reliable. If a battery dies while you’re on vacation it can either leave the valve closed and not water anything at all, which is critical during the summer, or it can leave the valve open wasting hundreds of dollars in water and possibly killing plants. The hard-wired controller is usually located in a garage. It’s wired into the building’s electrical. It then has low voltage outdoor rated wiring that runs to the valves to control them.Where wires are spliced together, make sure to use grease caps to protect the wires from water.

Along with the valves, there are some accessories you must include. First is a back flow preventer or anti-siphon device. These keep irrigation water from being pulled back into potable drinking lines and contaminating the water supply. They are required on all irrigation systems. A lot of valves already come with the anti-siphon, just double check this. You will also need a filter to remove any debris or deposits. This will save your emitters or hoses from getting clogged. Additionally you will want to have a pressure regulator. The common household water pressure is around 50 psi. Drip irrigation needs 10 psi to run optimally. Higher pressures will blow out the emitters or hoses.

Tomorrow I’ll cover how to size pipe and possible ways to lay out your irrigation in vegetable beds.

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Watering – Hand watering vs. Irrigation

As promised, here is a repost of my irrigation series.

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Some of you may not even need this post because you are blessed with summer rains. This is for those of us that live in dry summer areas.

I live in the classic Mediterranean Climate. Cool, wet winters and warm, dry summers. It’s very very unusual for us to get any rain between June and October, which is most of our growing season for warm weather crops. No rains means we have to use additional water on our garden.

At our last house we built several raised beds. The first year we hand watered them. It was a pain. I hated it. After coming home from work the last thing I wanted to do was stand outside in the 100 deg heat watering each plant individually – sometimes taking over an hour to do. I never had time in the morning to do it, which is the best time to water. With hand watering I found myself taking shortcuts – not watering long enough – and the plants would suffer.

This is T Tape, which we used for 3 years

The following year we decided to hook up a drip irrigation system. It was the best thing we ever did. It wasn’t automatic, we just used a pneumatic timer and hand turned ball valves at each bed. All we had to do was open up the valves on the beds we wanted to water, set the timer and walk away. Very easy to do in the morning. The plants did better and we had less issues with disease, which can be common with overhead watering.

Last year we were in a huge rush with everything we had going on that we just quickly put in the same kind of system just so we could have something. This year, however, our project has been to put in a fully automatic system. I will go over the major parts you will need to install your own system over the next couple of weeks.

So why do irrigation besides convenience? Simply put, you will use a lot less water and cut down on disease. Plus you can get a fertilizer injection system, which can make fertilizing just as easy.

Drip irrigation allows small amounts of water into soil over a period of time. Because of it’s slow release of water it drastically reduces runoff because the soil – even clay soil – can take in the water at the rate it is applied. Also, you can put water directly at the plants root zones if you use emitters instead of soaker hose. This reduces weed competition because the areas outside of the root zone remain dry. Because you aren’t adding water all over the soil and it is all being absorbed you reduce the amount of evaporation of water into the atmosphere. You apply less water, but the plants get more water.

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