worm03

All About 

The Whizbang Row Cover 

Hoop System

By Herrick Kimball

( original dateline: 2010, then updated for this WORM essay in 2013)

The above picture of a baby zephyr summer squash was taken in my home garden. Notice how beautifully healthy the plant is. There is virtually no insect damage. This is the case even though I use absolutely no insecticides. Gardening is very satisfying when you can grow plants like that.

Here is another telling picture from my garden...

Those squash blossoms are glowing in the morning sun—they are radiantly healthy. Yes indeed, it is so satisfying to place a seed in the soil and have it grow into such a lovely plant. This is the way gardening should be. This is the way that I imagine summer squash grew in the Garden of Eden.

Now, look at this cabbage from my garden....

Again, no insecticide of any kind was used in the growing of that cabbage, yet it is unharmed by insects. The same applies to my cucumbers, zucchini, winter squash, and pumpkins.

This doesn’t happen because I live in some magical place where cabbage worms, cucumber beetles, and squash bugs do not exist. On the contrary, such enemies (and many more) are in my garden, and they would devastate my plantings.... if I let them. But I don’t let them.

I keep bugs away from my young and vulnerable garden plants with a barrier of Row Cover Fabric. But the fabric by itself is only part of the equation. And that brings me to the point of this little web site.

I am going to reveal to you here a “system” I developed (and modified, as explained at the end of this essay) for making hooped row cover tunnels in my garden. Here is a picture of what I’m going to teach you how to make....

That picture shows a row of hoops covered with row cover fabric. The hoops are made of inexpensive, long lasting 1/2” pvc plastic water pipe. What is not clearly visible in the picture is that the hoops are precisely spaced, in a straight row, and solidly anchored. furthermore, the row cover fabric is firmly secured to the hoops and will not blow off. Best of all, I constructed this row cover tunnel very quickly and very easily using my Whizbang Row Cover Hoop System. When you are done reading through this web page, you will understand my Whizbang system and you will be able to make it work for you like it works for me.

Before I get into the specific how-to details of this row cover system, I want to give you a peek inside a section of row cover tunnel....

Pictured above are two young zucchini plants growing safe and secure from various pestilences that would otherwise besiege them. These plants are also sheltered from harsh winds and rain, yet they get the sunshine and moisture they need. As you can see, the environment under the hooped row cover is ideal for getting plants off to a healthy start in life.

Later, when the plants have grown to fill the inside of the hoop enclosure, you simply remove the fabric (save it to reuse again). The mature plants will be healthy and strong enough that insects should no longer pose any significant threat.

Here is a picture of the same two zucchini plants shown above after they grew bigger and the row cover fabric was removed. The plants are perfectly healthy and ready to produce....

Now I'm going to tell and show you how my Whizbang system works. The elements of the system will be introduced in the following tutorial as they come into play, and the photos will help to explain everything very nicely. So let’s begin....

The above picture shows several elements of the Whizbang system. First, at the top of the picture is the hoop material. I use 1/2” (inside diameter) PVC pipe for my hoops. You can get this pipe in ten foot lengths at most any home center and it will cost you around three dollars for a length. Cut each length in half and you will have two five-foot-long hoops, which is the size I use in this tutorial. These PVC hoops will last many years.

Below the hoops in the above picture you can see three boards with holes drilled in them. One board (the bottom one in the picture) is called the Short Hoop Spacing Board. The other two are Long Hoop Spacing Boards. These three boards are employed to help position and install the hoops quickly, accurately and in a straight row. I’ll show you how these installation boards work shortly.

In the bottom of the picture are numerous hoop stakes. This next picture shows a close-up of a hoop stake.

These stakes are made of clear (knot-free) common pine. I cut them 7/16” by 7/16” and 10” long. As you can see, one end is sharpened to a point. I did the sharpening with a utility knife. It needn’t be perfect. It just needs to be pointed.

The other end of each stake (the top) gets modified with the knife too. At 2-1/2” down from the top I push the blade of the knife into each corner about 1/16” deep. Then I shave the sharp corners off the 2-1/2" length. This renders something of an octagon shape, which is close enough to a circle that it slides snugly up inside the 1/2” PVC hoop material. Here’s a picture showing the shaped top of a hoop stake more clearly:

The knife shaping on the top of the stake also creates a small “shoulder” that acts as a stop for the hoop when it is placed over the stake.

As you will see, these little stakes are integral to my system. They can be cut out of scrap wood using a table saw and easily shaped as needed in a few minutes. If the wood is straight-grained, the stakes will be sufficiently strong and rot resistant to serve their purpose for at least a couple seasons. Some will inevitably break, so make a few extras.

For the purposes of our tutorial here, we are going to make a hoop tunnel approximately 50 feet long. You can  make a hoop tunnel any length you want. You can make it two feet long for a single plant in your garden, or you can make it  200 feet long for a whole row of plants.

For a long tunnel you need to pound a stake into the ground at each end of the row. These stakes mark the center of the hoop span. String a line from one stake to the other, as this next picture shows:

The string serves as the guide for aligning the previously mentioned  installation boards, which are what we’ll use to position the hoop stakes, beginning as this next picture shows.

What you are looking at in the above picture is the SHORT hoop spacing board. The board is a 36” length of pine. A center line is made on the board (it is directly under the string line in the above picture). And a 5/8” hole is drilled on each end of the board 16” from the center. This renders a distance of 32” from hole center to hole center.

The idea is that you center the board under the string, square it up by eye at a right angle to the string line, and push or pound a hoop stake into each hole, as shown in the above picture. This next picture provides another view of what I just described.

Hoop stakes at 32” apart is what I determined to be reasonable for a five-foot long hoop. You can, of course, change any of this to accommodate the wider spacing that longer hoops would require. What I’m showing you here is what I’ve determined works well for my gardening needs. Feel free to modify.

With the first set of hoop stakes in place, remove the short hoop spacing board and push the hoop stakes in until the shoulders are at ground level), you can now position the next two hoop stakes, as shown in this next picture.

What you are looking at above is the two LONG hoop spacing boards being used with the short hoop spacing board to position the next set of hoop stakes.

My LONG hoop spacing boards are made of 1/4” plywood. They are 40” long and have a 5/8” hole at each end. The holes in each board are 36” apart. That distance of 36” is how far apart I determined that I want to space each hoop in the row. Again, if you want, you can modify your LONG hoop spacing boards to extend or shorten the distance between hoops.

Note in the picture above that the hole in one end of both LONG hoop spacing boards has been placed over the first set of hoop stakes. At the other end, the holes in the short and LONG spacer boards are aligned, and the center line of the short spacer board is positioned directly under the string. Once the assembly is thus positioned, you can insert the hoop stakes for the next hoop into the holes. The three previous sentences by themselves are kind of hard to understand but the picture below tells the story.

You will notice that, viewed from the side, the center of the short spacer board is not directly under the string. This illustrates why it is important that you align the short spacer board while looking directly down the string—not from off to one side. Your eye can only be trusted when you are looking directly down the string. For example, this next picture shows a view down the string and it is obvious that the short spacer board needs to be shifted to the left.

In like manner, the short and long spacer boards are used to continue spacing and placing hoop stakes all the way down the row. This next picture shows the boards being positioned for placing the third set of hoop stakes. You can see the first set of hoop stakes in the foreground and then the second set of hoop stakes is being used to hold one end of the long hoop installation boards.

As the next picture shows, I have put the hoops on the first three sets of stakes and the fourth set of hoop stakes is being used with the spacer boards to position the fifth set of hoop stakes.

The sequence of stake and hoop placement goes very quickly once you get the concept. And if you utilize the spacer boards properly, precise and straight placement of stakes is assured. Here’s a picture of yours truly bending a PVC hoop and putting it on some stakes.

This next picture shows a close-up of a hoop about to fit over a stake.

And here is a picture of a complete row of hoops.

Those hoops are freestanding and surprisingly steadfast.

The next thing to be done is to put the row cover fabric in place, as shown all completed in this next picture.

You will notice that the row cover fabric is anchored to each hoop with a clothespin. I thought I was pretty clever using clothespins like that when I first came up with my hoop & stake system. But I soon (very soon) discovered that clothespins do not work for this purpose. They look like they work just fine in the picture, but before long every clothespin broke. The stress of being forced open way beyond what they are designed for led to failure.

But it was evident to me that the concept of somehow clamping the fabric to each hoop was a darn good idea. Free-floating the fabric just doesn’t work very well at all (it blows off). Heaping soil on the edges of the fabric to hold it down is too much work and it takes too much time. The same goes for those U-shaped “soil staples” I’ve seen in gardening catalogs. I can tell you with certainty that nothing works easier and better than some sort of clothespin-type clamp.

That being the case, I came up with my own homemade row-cover clamps. I’ll show them to you shortly. Before I do, I want to show you this picture of the inside of the covered row of hoops.

That environment inside the tunnel is ideal for getting plants off to a good start in the spring. And here is a picture of the outside of the row:

Please note in the above picture that the row cover fabric is somewhat loose between each hoop. This is necessary because the row cover clamps require some material slack. This is especially true with the homemade clamps I'm about to show you. That being the case, you want to figure that you will need 3’4” of fabric is needed to span from hoop to hoop (when they are spaced apart 36” as this tutorial recommends).

And notice also that the end of the tunnel is sealed. This is accomplished by bunching up the extra fabric at the ends and weighing it down with a rock. You will need 2’6” to 3’ of fabric at the ends to seal it properly.

Now, about those homemade clothespin-type clamps I made....

The clamps in the picture above (ones I've used in previous seasons) are made out of 3/4” thick pine. The dirty, weathered ones have been used for a couple of seasons already. Each clamp is held together with segments of bicycle inner tube. Unlike a rubber band, which will deteriorate in the elements very quickly, the butyl rubber inner tube material will last for several seasons of use. The wood clamps themselves will last for a good many years.

The amount of pressure you get with these homemade clamps is not great but it is sufficient to do the job. The 3/4” wide notched jaws grip the cloth-covered hoops very well.

Here is a mock-up showing hoop, fabric, and clamp.

I recommend that you purchase 6’ wide row cover fabric for hoops of this size. That will give you 6” of extra material on each side. After the fabric is draped over the hoops, fold it over on itself a few times (like shown above) and clamp it down tight to the ground at the base of each hoop.

Thus secured, the fabric will not blow away. I’ve had some very gusty winds blow over my garden and have never had the clamped fabric on a hoop tunnel come loose or tear.

Here is a picture of hoop clamps in my garden.

In the above picture I have removed the row cover from an established planting of cucumbers and I put several clamps on one hoop so they would be together and dry out before I collected them up.

To open the hoop tunnel in order to cultivate around the plants, you simply unclamp the row cover fabric along one side of the tunnel, gather it up, and re-clamp it on top of the hoop. This opens up one half of the tunnel and the row cover is secured so it won’t blow away. Then, after cultivating as needed, it's a simple task to reposition and clamp the fabric back in place.

If you put this homemade hoop & clamp system to use in your garden, I’m sure you will agree that it is truly a Whizbang idea.

Important
Updated Information

Since publishing the above essay to the internet in the winter of 2010, I have modified my hoop system. First, I no longer use the homemade clamps to hold the fabric, opting instead for Mark Albert's clothespin and baling twine cloche system. The homemade clamps worked fine, but with Mark's system the row cover fabric can be stretched more tightly over the hoops, and easily cured with some common clothespins. It is a more secure system, especially in a windy environment.

Also, I no longer use the homemade wooden stakes because they have a tendency to break. I bought some 1/2" aluminum dowel rod and had a machine shop make some custom hoop stakes, as you can see in the picture below. The stakes were not cheap and are something of an extravagance. But after a few years of using the hoops I knew the system was sound, and I expect to be using it to some degree for the rest of my gardening years.

These custom-made aluminum hoop stakes are 10" long. The top 2-3/4" is machined to a little smaller diameter (than 1/2") so the pvc hoops will easily slide on. The reduced diameter creates a bit of a shoulder, which acts as a stop for the hoop (like on the wooden hoop stakes I used to make). I pound these into the ground with a dead blow hammer, so as not to deform the soft metal. (if you click on this picture, you will see an enlarged view)