The third area to discuss regarding season extension are those structures that are simple enough to disassemble and relocate to another spot-primarily referring to Hanley Caterpillar Tunnels.
The real lure of these buildings is their low cost and simplicity to move. Generally the area is prepared in advance and then the tunnel is moved over the area when the planting is to be done.
Since the original design specified 6′ hoop spacing, the intent was always to remove the cover before risk of heavier snow fall. More often now, growers are going to 5′ spacing (and sometimes 4′) to allow the covers to remain on longer or even permanently.
By having a smaller hoop spacing, it allows the cover to stay on permanently, which allows for a much earlier start in the spring.
The key to the concept of the hanley working is in the rope.
- The back and forth pattern of the rope resembles the way a person would lace up a boot.
- Typically there is a spring loaded clip at the base where the rope passes through.
- Once the rope is fully installed, it is important to tighten it through three passes from end to end.
- If the rope is not tight enough, the wind will create wiggle and movement sideways.
- When the plastic is tight enough, it also allows the grower to slide the plastic up the hoop to allow ventilation.
Generally the plastic is about 25′ longer then the tunnel.
This allows the installer to bunch up (pig tail style) the extra poly at both ends between a pair of posts.
It is important to get the plastic as tight as possible lengthwise first.
There must also be a rope from the top of the last hoop to the tie off post.
There are a couple of challenges to consider with the hanley tunnels.
- One of these challenges is to create a proper entrance. Typically entrance is achieved by slightly lifting the plastic and ducking underneath.
- The other are of challenge is the low shoulder height of the structure. This restricts the use to a couple rows of taller items in the middle and a couple rows of shorter plants along the side. The width of the tunnel does lend itself to three regular size beds.
Once you have learned about the nuances of the hanley tunnels, and asked any questions that come up, you will be better prepared to have these efficient season extenders work for you and your application.
Feel free to look at our Hanley Application page for more information and photos, and give us a call with anything else you require.
We are pleased to have many happy customers these structures are working for, and look forward to you being next!
This concludes our week long series of Season Extension. Check out our new book if you want to know more “So You Want to Buy a Greenhouse…Your Guide to Planning a Greenhouse Purchase”