Last October I decided to construct a high tunnel 10 X18 to extend the growing season. Not knowing what to expect, what could possibly "grow" wrong?

Advantage #1 - Being in there with no shirt on soaking up the rays is awesome in late February when the sun is bright and there is little to no wind. 75 degrees was not uncommon once the sun was out in full force. Wife thought I was nuts being out there, but what does she know?

Disadvantage #1 - All things come to an end, and quickly. Once the sun goes down, the temps crash quickly to a degree or more above what it is outside. Nothing to hold the heat, so at night, anything left in there will suffer.

Advantage #2 - No Wind! This is probably the biggest thing I noticed. Seems like the plants really perform much better when they are not being hammered by those cold spring winds. The wind chill can really drive them temps way down in the early spring.

Disadvantage #2 - No Wind! Once the spring sets in, you have to get the air moving or your in for some headaches with bugs, humidity and rust. I installed some fans opposing each other to help move the air around.

Advantage #3 - Growth rate. By far, in a somewhat controlled environment with little effort, plants out perform anything I've grown before. I had tomato plants over 10ft tall by early June and we planted early April. Figs didn't really start to do much until June as this was my first year growing them and most were from cuttings except two 1 year old trees from Dave Wilson Nursery.

Disadvantage #3 - Growth rate. So what do you do when the plants are trying to push through the plastic and you still have a few months of growing to go? Clip them, so they can branch out and then have more branches to push through the plastic. I ended up loosing a few tomato plants as they collapsed from the weight of the fruit but quickly grew from what was left of them and once again reached the top of the high tunnel in a few months. The 1 year old figs were clipped three times as they just seemed to have a life of they own.

Advantage #4 - Water. Heavy rains are no worry. Disease seemed to be minimal and I think this was from the plant foliage staying very dry.

Disadvantage #4 - Water! Seems like things in containers in a high tunnel drink more water than when outside. I have 600 gallons in two IBC holding tanks and did eventually run out of water during the middle of summer. I was watering twice a day at once point. My drip irrigation system needs some adjustment as the pump I was using seemed to overheat and shut down on a regular basis.

Advantage #5 - Season never ends! Well, it does eventually when the first cold weather rolls in. 2 weeks ago I still had pepper plants in there flowering with peppers still on the plants. The figs trees still had their leaves and were all very happy. One cherry tomato still had plenty of fruit and was still flowering. The recent cold snap shut everything down and it was all over with hundreds of fig leaves on the ground, peppers wilted from the cold snap, although the cherry tomato plant seemed like nothing could kill it.

Disadvantage #5 - The season never ends! Cleaning out containers mid November putting everything away for the year sucks! Now the madness begins on what can I grow in their next year. 4 more months of surfing the web, reading message boards, and watching auctions. Debating weather or not this property is really big enough to begin with, and wondering why I didnt build the high tunnel bigger to begin with.

Here's a pic of the VdB 1 year old Dave Wilson tree. This thing was about the thickness of a pinkie finger in March when it arrived. Needless to say, it appeared happy in the high tunnel.


So if your thinking about building a high tunnel, besides the cool factor, and neighbor envy, it's well worth it.

Not sure if you where growing your toms up string, because this helps. soon as the tom hits the top you can undo the string and let the vine arc at the bottom gaining another 3-4 foot.

Sweet!!!!

thanks for the report, I have been thinking about building one myself and this is very helpful, nice tree too

Congratulations.  I hoop your fig output increases.  Next year you might as well build yourself a greenhouse and heat it in the winter.  You know you wanna.

Great post RIMike, thanks for sharing.

Do you cover your tunnel with one layer of plastic or 2?

I use 2 to cover mine, but I think it probably blocks out too much light.  My test tomatoes got big and spindly and wouldn't flower/fruit.

RCantor - I just started a sunroom with 2 9foot windows on the east and south walls. You must be a mind reader.

Just one layer of poly. Usually with two layers you inflated the space between them to use as an insulator. You need some kind of fan blowing air all the time. Never looked into it as it was hard to justify heating it.

That VDB is really impressive from one year's growth!  That would take me 2-3 years, even in San Diego!

Yes, I would have said it was a freak thing, but both VDB trees I had grew with the same vigor.

Hear they are just leafing out in early spring. Not much more than the bamboo support holding them up.