Hoop House: A $30 or less Greenhouse Made With PVC Pipe and Plastic for Your Melon Needs

Opened Hoop House Shortly After Planting

Growing Melons in a Short Season Cool Climate is Perfectly Reasonable

Back in January when my newborn was still completely immobile and required me for everything, I had a brilliant idea.  I should grow melons in the Pacific Northwest!  I was reading an article about the thousands of dollars, primo perfection melons selling in Japan, slightly dehydrated from constantly breastfeeding, and completely sleep deprived.  Naturally, melons came as a brilliant idea.  For those of you who don’t know, the Pacific Northwest has a fairly short growing season and incredibly mild climate.  What do melons need?  Heat.  Lots of heat.  Yeah, we don’t have that.  They also need a long time to get going.  Yup, don’t have that either.  Doesn’t matter.  Mama wanted fresh, locally grown melons.

My initial instinct was to convince my husband we needed to drop a few thousand dollars on a heated greenhouse, but I realized I could just buy the multi-thousand dollar Japanese melons for that price and had to figure out something more cost effective.

Cheaper Alternative to a Greenhouse

Enter the hoop house.  Or hot house.  Or cold frame.  Or miniature greenhouse.  I don’t know what it’s called, but I’m going to stick with hoop house.  This is a structure made entirely with PVC pipes, and if you’re feeling fancy like I was, rebar you “borrowed” permanently from your father’s shop.  The structure is fairly inexpensive to make, running roughly $30 in materials tops for a 12 foot bed if you don’t have any extra supplies running around, and it has increased the soil temperature during 60 degree weather by roughly 15 degrees.  This is the difference of being able to plant melons (or tomatoes, peppers, sweet potatos and yams, etc…) in March and worrying about frost to knowing everything will be fine.  Half of my plants outside the hoop house died due to unexpected early cold, where as everything inside stayed nice and toasty.

Green tomatoes, bell peppers, and melon blossoms in July (and weeds. Ignore the weeds.)

I used 5 ten foot PVC pipes for a 12 x 3.5 foot bed, spacing about 3 feet between each pipe.  I also used 10 ft x 100 ft 6 mil plastic sheeting from our local hardware store the first time, but when we ran out of plastic at my mothers we used 12ft x 50 ft 1.5 mil plastic instead since it was 1/5th the cost ($10 as opposed to $60 at the time of writing this).  Keeping in mind this plastic will not last forever due to the fact it is going to be exposed to the sun and PVC, the less expensive option isn’t a bad one.  You can also use an old garden hose to keep the plastic from touching the PVC if you’d like.  Next, you need two spring clamps per PVC pipe.

Construction is simple.  Put a rebar or just the pipe evenly spaced across the bed, carefully bend the pipe over the rebar (thicker pipe will survive the bending more easily – I used 3/4″ pipe, but my mom used 1.5″ pipe and inserted straight into the ground).  Pull plastic over the hoop house.  Cut to fit.  Clamp on using spring clamps.  It’s that easy.  You have a greenhouse in under 30 minutes, with the only part you need someone to watch the baby for being the hammering in the rebar part.

Total Materials:

5 ten foot 3/4″ or larger PVC pipes (1 for every 3 feet + 1 for the end)

12ft x 50 ft 1.5 mil plastic (at least 10 feet long, 12 preferred if you have bunny problems)

1″-2″ clamps , two per PVC pipe (10 total for me – $1 each at the hardware store, or half the cost at the link).

2 one foot rebar per PVC pipe (optional – but helpful if you have clay soil – if you have soft soil you can just push the PVC pipes in)

Melon Success?!

So far, I haven’t seen any melons yet, just little blossoms everywhere.  However, the melon plants haven’t died, which from farmers I’ve talked to in the area is on its own success so far.  However, one thing I did notice is my bell peppers, cayenne peppers, tomatoes, and tamatillos have all fruited much earlier than they typically do.  Last year I was just starting to get tomato fruit showing last September due to the cold, and with another cool spring, I already have tomatoes on the vine as of early July.  I’ve also had peppers for about a month now, which is absolutely lovely.  I’m still holding on to my melon dreams, but if nothing else I do intend to continue using the hoop house for extending my lettuce season / protecting it from bunnies and other pests during the winter.  I honestly didn’t have to weed this portion of my garden at all until about 2 weeks ago when I opened the side of the hoop house to let it breathe on hot 90 degree weather days.  That alone is a massive boon for those of us with little ones running around!  I will update after melon season is over and let you know if I’ve had any luck.

Additional Benefits of a Hoop House

More heat, less weeds, fewer pests, less watering needed.  So, the fact it makes everything warmer is an obvious, but you’ll notice that first picture has significantly fewer weeds in the garden bed than later when I opened up the hoop house full time.  In fact, I didn’t need to do any weeding until I started having the hoop house opened full time because nothing could get in.  I naturally had to open it up for fertilization later on so the bees could get in, but even in my area covered with bunnies, they have completely left my produce alone with just the sides of the hoop house open.  Additionally, since the hoop house, like a greenhouse, is naturally more humid, I didn’t need to water it as frequently during Seattle summer drought time.

Hoop House Downsides

There are two notable cons, however.  One, you either need to install a soaker hose, which I did, or remove the hoop house cover to have it watered.  This means paying attention to the weather forecast and taking it off when it’s going to rain or paying to water the plants.  However, due to the fact that the humidity made the watering requirements significantly less than the rest of my yard, I didn’t take this to be a massive draw back.

The second down side was that slugs love how humid it is inside.  Most of the plants I have aren’t something slugs love if they aren’t seedlings, but the bell pepper plant did not have a great time at the start.  They did end up killing one bell pepper seedling that I didn’t catch in time, but otherwise everything has thrived.

My mother’s hoop house with plastic removed for her tomatoes

A Case for Using Organic Fertilizer Instead of Using Homemade Compost

Side note, my mom used actual fertilizer instead of just mixing in the fecal matter from her animals, and her plants are huge.  Like, busting out of her hoop house so she had to take the roof off huge.  I’m curious about our yields, but for about $10 of liquid fertilizer she has plants much larger, bushier, and more well fed than mine.  I’ll have to do a follow up and look at my own ratios of goat/chicken poo being added to my soil.