Went to a presentation on raised beds and hoop houses the other day. The speaker had constructed raised beds with hoop houses over them. She used electrical conduit clips screwed to the outside of the boxes to support the hoops. She made the hoops from 12 foot lengths of 3/4 PVC.

Here's the cool part. To secure the row cover fabric, clear plastic, shade cloth, or bird netting to the hoops, she used long lengths of old garden hose and split it lengthwise to fit over the hoops with the fabric sandwiched in between.

If you try it, let us know how that holds up in wind!

I haven't tried the method personally, but I have seen the set up and am very familiar with the area. The winds are frequently very high. By high, I mean 20-30 mph sustained, commonly gusting to 50-60.

I've already survived the worst of the windy season here, but in the fall, I am definitely going to use the split hoses in place of my collection of binder clips.

Even in a wind, they would surely work on bird netting. Got to try this to keep the rabbits out of the lettuce bed. Much easier than pounding re-rod and fastening the netting to it with cable ties.

That sounds pretty cool; couple of questions.
1. How wide were the beds?
2. How far apart were the hoops?

This is just about what I was planning on doing next year as I switch to raised beds, except I'd never heard of the hose part, and wasn't sure how I was going to fasten the hoops.

I sewed my shade fabric on the PVC. Seems like the hose is a great idea. Even if it didn't do the whole jobe of holding in the wind... you could sew w/ MUCH wider stiches! String would hold hte hose closed over the fabric.

I've got lots of old hose that everyone is always telling me to get rid of. I use it to network my soaker hoses. Now I've got a new use for it!!!

evelyn
In SoCal, land of the Santana winds

The owner of the garden has beds ranging from 4x4 to 4x12. She said that she preferred 4x6 because of the size of her garden space and the ease of reaching to the center of the bed from all sides without stepping in the bed.

Since the presentation, I've toured a few other gardens that have similar set ups, and have become convinced that a standard size bed of 4x8 would make best use of material. (2x6 lumber is most economically sold in 8 foot lengths).

If the beds are longer than 8 feet, you may have to add some intermediate posts in the middle to keep the sides from bulging out from the weight of the soil.

I've also decided that it makes sense to settle on a standard size and length of hoops (i.e. 12 feet) so that all of the row covers, bird netting, shade cloth, etc, can be cut to the same size and be interchangeable so that you can re-use and not have to figure out which cover/hoops/hose go on which bed.

I've seen hoops of 3/4 PVC. I was surprised to see that it could be bent to such a tight ellipsoid, and I worry that it will become brittle over time and with exposure to sunlight.

I've also seen hoops of 3/4 PE (PolyEthylene) and I think this would be better because it's more flexible.

I am told that the hoops will last much longer if they are painted with white or silver paint, but I'm thinking that PE pipe would last a LOOOONG time regardless. PE is also cheaper, but you have to buy it in large rolls, so you would want to team up with a friend.

The spacing of the hoop supports is 24" on center, and this seems adequate for the winds we have here. If your garden was subject to especially high wind loads, you could go to 16" O.C.

It was recommended to me that I set up my beds so that the long dimension was perpendicular to the prevailing wind.

I understand that the folks here who are doing hoop house gardens are adding 30 days to each end of our typical 100 day San Luis Valley season.

The only question I have remaining is what material to use for constructing the beds. I want something more durable than standard 2x6 framing lumber, I'm skeptical of even the new "improved" and purportedly "safe" pressure treated lumber, and I hesitate to use redwood because I am still not convinced that it is sustain-ably harvested.

One thought is to line the inside with Visquene. Another is to mop on a layer of tar to the inside, but I'm nervous about that too.

quote:

Originally posted by trinharder:
That sounds pretty cool; couple of questions.
1. How wide were the beds?
2. How far apart were the hoops?

This is just about what I was planning on doing next year as I switch to raised beds, except I'd never heard of the hose part, and wasn't sure how I was going to fasten the hoops.

I think I answered your questions above. In Parker, you get a longer season than I do, but you get the same nasty dessicating wind in the spring.

...Oh hell, there's a hails storm coming... The gal that did the presentation says that she t me i

Thanks, that answered my questions, but that brings up another one. Is it flexible PVC? I can't imagine bending normal PVC to that extent, but I've never tried. Is that what he was using, normal 3/4" PVC pipe, or a flexible variety?

WOW, rain gauge measured 3/4 inch in under 30 minutes!!!

Where was I...

Our presenter covers the top and sides only of her hoop houses and leaves the ends open. She uses clear plastic instead of "official" row cover material. She also leaves the covers on all season.

She says she pulls the covers only if the plants inside get too tall. This probably makes sense here in the San Luis Valley where we can have a frost ANY day of the year, and where it frequently gets down in the low 40's even in July and August. Also, since we are at 8000 feet, the thinness of the air probably compensates for any loss of sunlight due to the cover fabric.

Anyway, as I add new raised bed boxes, I am going to build them of two "lifts" of 2x6 lumber. These will be reinforced at the corners with 4x4 posts which will NOT be sunk into the ground. I will fasten the corners with 1/4" x 3" galvanized lag screws. I will install two conduit clips, spaced 8" vertically on 24" centers along the long sides of the box.

I will settle on standardized 12 foot long hoops and cut standard panels of bird netting or row cover material as necessary to cover each box.

At least, that's the plan THIS week.

Hey Tryin'

She's using standard PVC, but frankly, I don't know how she managed to bend it. While I was surveying the hail damage a bit ago (not much damage) I found an 8 foot stick behind the shed and tried to bend it. I didn't bend it to the breaking point, but it seemed too brittle to me. I'm thinking maybe 3/4 pvc electrical conduit would be flexible enough, but I'm going to use polyethylene because it's half way bent to shape already anyway.