Hidden Valley Hibiscus Forum

I'm going into my 4th year growing hibiscus, and I suppose it's about time for a greenhouse.  My collection has gotten much too large to stay inside.  In fact, it probably was last year as well... but that's another problem.

As per usual here in California I have a teeny, tiny backyard.  My entire property measures about .12 of an acre.  So, as you could imagine, potential locations for this greenhouse is somewhat limited. 

I finally settled on the south side of my house for two reasons.  Number one, the valley in which I live becomes a giant bowl of fog for the majority of the winter (I'm between Tracy and Stockton for you NorCal-ers).  At times we can go a month or so without ever seeing the sun.  Sunshine being the commodity that it is here, the south side of the house seemed most fitting.  Secondly, I just don't have anywhere else to put the greenhouse that wouldn't involve killing the grass.

The south side of the house is somewhat of a no-man's land.  I can't keep hibiscus there during the summer, as it gets full sun all day and is WAY too hot.  I don't even like to go over there during the summer.  As you can see from the picture, I haven't exactly done much with it.  Frankly, I don't even bother to pull the weeds that grow from in-between the concrete slabs... until now. 

This area was originally covered in old, dusty gravel full of random metal and glass pieces.  I think the people that owned the house before parked an old car here.  I shoveled most of the gravel out, with a little left to go.  You can see where I've started to sweep up the last of the dirt and gravel.  In case you haven't figured it out, big box = gh.

The fence over here needs to be replaced, but hopefully our neighbors will get tired of looking at it before we do.  They've already mentioned it once.  I just hope it doesn't fall on the greenhouse.

And now, for the greenhouse specs...  it's a Spring Gardener greenhouse from Lowe's:
 
http://www.lowes.com:80/pd_4071-1298-IS+70810_0__?productId=3192597&Ntt=spring+gardener&pl=1&currentURL=%2Fpl__0__s%3FNtt%3Dspring%2Bgardener&facetInfo=

I  actually didn't choose it.  It was a birthday present from my mother.  I hope it does the job.  It has 80 sq. feet of floor space, and is 8' tall.  I will definitely need to install shelving.  I'm planning on putting an electric space heater inside so the temperature never gets below 70 degrees.  I'm also back and forth on whether I'd like to buy more gravel or simply use my uneven sidewalk as a floor.

All for now...  stay tuned...

Your electric bill will be through the roof! I would set it to 50 as low instead. At night your heater will run continuously trying to keep it at 70. My greenhouse heater runs on gas and it cost me a lot to heat just to 50 all winter.

Keep us posted on the build. I love greenhouse pictures.

Have you started putting it together, Jordan? If it is a little intimidating let us help you with it. Surely we can offer lots of armchair helpful hints and encouragements as you go :)  Seriously, it's not as hard as it may seem before you get started.

Len makes a good point about heat. Although it would be great to keep the temperature at 70F that is often not an affordable goal. To do much good you need to keep it at least at 50F and I have noticed over the years that for every 5 degrees I can increase over that I see definite improvements in the plants. I usually aim for 60F as a happy compromise. You will be able to experiment and see what works for your situation.

Charlie

 

Im excited for you Jordan.  If it helps with the argument about temps.  My house is set at 60º and my hibiscus stay healthy, happy, and blooming. (once they get settled from being outside).  The temps do raise a bit in the living room when we start the wood stove, but in the office where most of them are, it is usually 60.  Good luck!

Thanks all!  It's right up against the house too which should help with the heat situation.  I'll try 60F for the first month and see if that kills me, then adjust accordingly if necessary.  I did finally get it all the way up and together.  It was easy except for the cover.  That thing goes on there tighter than a broom in a witch's, um, butt...

I ripped the cover trying to put it on.  I figure masking tape will fix that.  I haven't actually put any plants in the gh yet, but will probably start tomorrow.  I have the little guys in the house as it has already gotten down into the low 40s here.

Here are some photos of my plight...

All the parts, frame going together, cover going on (guy is DH who thinks I'm nuts, but loves me anyway)...

I just realized I don't have a photo of the final product.  I'll have to take one tomorrow.

Looks good jordan!

50 should be fine as the low temperature.  When temps are in the 50s at night, hibiscus still grow and bloom fine.  During the day the sun should warm the greenhouse considerably and temps will likely be in the 70s and 80s at least.  The point of a greenhouse is to trap solar radiation and due to the glass or plastic, allowing it to stay warmer at night, before the sun can heat it up again in the morning.   Ive gotten my hibisucs to grow and bloom during our spring in Seattle, where the high temps are in the 60s and lows in the 40s and 50s.  You will be suprised at how well they still do at lower temperatures, and you will get some amazing coloration!  The plants grow slower and taking longer to develop buds, but if it leaves extra money in your pocket, its worth the trade off :)

Ok, we're up and running!  (kinda)


I put everyone in there that would fit.  Today is my day off, so I'm going to Home Depot to buy supplies to build shelves.  It's really crowded in the gh right now, with little room for me to water/inspect, etc.

I think I'm going to end up moving the gh to a sunnier area in my yard.  Because the sun is so low right now, it's not getting much direct sunlight and thus not heating up like I would hope.

It's super-humid in there too, and closed buds are actually festering with mold if I leave them on the plant.  Something I'll have to pay attention to this winter.

Hey Jordan,

I had to deal with mold problems up here in the PNW in the winter (its everywhere)  and I found that just getting a few fans going in the grow area fixed that.  For your greenhouse I think two box fans would work nicely.

Jordan great job!  That greenhouse is a great idea.  Looks not too tough to put together and if it is already that humid inside it must be working the way it should.  Your plants in the pic look so healthy and well taken care of.  A pleasure to see.

Can't wait to see some more awesome blooms.

Farmer D

How's the greenhouse working for you Jordan? I am browsing the internet for greenhouse ideas and tips because I will be needing one next year. There will simply be no room in my house for them next year! What do you use for a heater? Just a plug in space heater? Do you worry it's a fire hazard? Any tips or tricks you have discovered that you could share? I hope they're thriving!

Thanks!

Oh, boy, Denise...  has it been a saga!  I'm not sure that I have the best quality greenhouse.  It was a gift, so I suppose beggars can't be choosers.

The first problem I had with it was my choice of location.  It was set in a spot on the south side of my house that I thought would get great sunlight, but with the sum so low in the wintertime, the house next door blocked all the light.  At that point I had an electric space heater inside it, so it was warm, but with the sudden decrease in light the plants weren't happy.

I moved the greenhouse to a spot in my yard that gets the most direct sun--  about 5 hours currently.  Then came the problem with heat.  The gh is already drafty as it's not even really connected to the ground.  I think the R value is very low as well, as within an hour of losing sun it's the same temperature inside as outside.  It's basically a tent that just sits on top of the grass in my yard.  Well, my little electric heater blew the breaker, so now I have no power to the outdoor outlets or any of my bathroom outlets.  I went and bought myself a Coleman propane heater after a couple of cold nights, and was using the little propane tanks that are made for those tent heaters.  The first heater I bought was 1500BTU and wasn't NEARLY big enough to make a veritable difference in temperature in that drafty thing...  so I went and bought the bigger Coleman heater (3000BTU) which is turning out to be barely enough.  The new heater was eating up one little propane tank every three hours or so, so I went and bought a 20 gallon tank only to find that the bloody thing needed an adapter to connect to the heater.  I bought one of those too...  and am going through 20 gallons of propane every week or so.  I don't have a thermometer, so I'm not sure how warm it stays inside now, but I'm guessing around 5 degrees warmer than outside.

On the positive side, it didn't blow away in the wind in the past couple of days.  The wind blew right through it, though, and took all the heat with it!

*facepalm*  So that's where we're at right now.  Sorry I don't have a better story to share!  I've lost a few plants to wilt disease already, too.  My suggestion would be for you to spend what you can to get (or build) the best greenhouse within your means.  Do research on heat retention.  Definitely don't get the Lowe's Spring Gardener gh!  I don't really worry about fire, as I have the propane tank and heater out in the middle of the gh and away from everything.  

Oh man, sorry about all of that. I was definitely hoping to hear a better report than that :( Yes, the greenhouses I was looking at online were all around $150-$250 and look like the one you have pictured. Yikes, was hoping to get away with spending no more than that. Maybe I will just have to rearrange my house a little more creatively next year... currently I have 4 plants in the guest shower, 3 on the kitchen counter and 3 toughing it out outside. I have 4 coming from HVH this Spring...and my heart set on several more!  :D My house isn't very big!

I saw online someone said they just use a lamp with a 150 watt bulb in it and strings of Christmas lights to heat their greenhouse. I wonder if that would even work??

I bet you are spending a lot on propane then huh? I wonder which is more expensive: propane or electric??

Ahhhh....what we go through for these dang things!

Perhaps it would just be easier to move to a tropical climate.  :)

Where in the bay area are you Denise?  We're pretty close to each other...


I think lights inside are a good idea, and that may be what I try next winter.  I have some plants on my bathroom counter, and have just left the vanity lights on for them.  The lights warm up the room (door shut b/c of bad kitties) and the plants are nice and green, and actually growing!  There's not even really a window to speak of in there.

Jordan I'm in Concord. Where are you?

That's great that some of yours are actually growing. I had two in the bathroom and they both ended up dying! Argh. But the three I have in the kitchen are all growing new leaves--so exciting!!! I wonder if the Supernova and HVH fertilizer I started is the reason? Or the sun for about 4-5 hours a day. WHO KNOWS!? :)

Any direct sun is a huge help...  and I'm sure the fertilizer and Supernova help too!  Were you leaving your lights on in the bathroom 24/7?  My lights in my bathroom are bright, and I leave them on all the time.  That may be why my hibs in there are doing well.

I lived in Milpitas for 4 years when I was at SJSU, then bought a house in Lathrop a little over 2 years ago.  I work in Dublin, so we are fairly close!  So cool!  Shoot me an email if you want--  forsaken_lioness@yahoo.com

Jordan, there are lots of ways to make a less-than-perfect greenhouse better. Charlie and I have had our share of funky greenhouses that we really had to work on!  Greenhouses are expensive, but any greenhouse is better than no greenhouse, and with a little work, you can make any greenhouse air-tight.

Getting the side walls to reach the bottom and have excess plastic that folds down onto the ground is really important. This is the quickest and easiest, low-tech way to do that:

Get a roll of greenhouse tape ("Poly Patch Tape" usually 4" wide)and greenhouse plastic ("Poly Cover"), or even bubble wrap - anything will work. If you can't find it at a local store, you can get it online at www.charleysgreenhouse.com . More expensive greenhouse coverings last longer, but anything will work for one winter if you are on a budget.

Lay the plastic all around the outside bottom of the greenhouse, with the top half up on the walls and the bottom half folded outside on the ground all around the greenhouse - an L shape all along the bottom of the greenhouse.

Tape the top of the plastic to the greenhouse wall in a solid line that leaves no gaps.

Then put something heavy (bricks, cinder blocks, heavy boards, or anything heavy!) on top of the plastic, right up against the greenhouse wall. Make sure the plastic is weighted down all along the bottom, around the corners, everywhere.

Use that same greenhouse tape to patch any holes anywhere else in the greenhouse. Patch all holes tightly. Holes are inevitable!  We all get them all the time. Patching holes is a frequent job for greenhouse owners.

Once you get your greenhouse airtight, add a little fan to your propane heater to force some circulation and blow the warm air all around the greenhouse. It will help keep all the plants uniformly warmer. Try to put it up high if you can, on a top shelf or hanging from the ceiling, and blowing from one end of the greenhouse into the center of the room.

If you want to go all out and make a super greenhouse, buy clear bubbled greenhouse plastic, and cover your whole greenhouse with it. The bubbled plastic gives the effect of double-walling your greenhouse, and it will really make a difference with keeping drafts out. Make sure you use enough to fold down onto the ground all around the outside of the greenhouse, and weight it down with something heavy all around. Also seal up every seam completely with greenhouse tape. This costs quite a lot more, so you may not want to do it this year, but for future years you might want to consider it.

You don't need a "perfect" greenhouse to keep hibiscus happy. A little bit of extra work will make any greenhouse better, and any shelter is better than being outside and exposed to very cold weather. Even an unheated greenhouse will cool down more slowly than the outside air at night and heat up more quickly when the sun comes up in the morning. So even a funky greenhouse is better than anything you can do outside, like freeze cloth and Christmas lights.

I hope this helps!
Cindy

Cindy,

Thank you so much for the ideas!  I will definitely try some of them next winter.  Perfecting winter seems to be an art...  if it's such a challenge here, I can't imagine what it would be like in a colder climate!

Greenhouses are definitely as much art as science, Jordan!  We work on improving ours all the time, and how to improve it is a constant discussion point between Charlie and me. And now that we're starting to build new ones in this new colder place, even more so! There may be such a thing as a "perfect" greenhouse, but I think no mere mortal could afford it. So we all build greenhouses that fit our budget, then tweak here and there to improve them.

You'll get yours nice and air-tight over time. Greenhouse tape and plastic work wonders! :-)

Cindy

Jordan and Cindy I wanted to thank you for this thread.  I learned a lot and hopefully enough to properly grow my seedlings inside the house without getting them in the way.   My little home made creation of sorts.

Just a simple plant rack with adjustable shelves and plastic cover.  The trick was to come up with a way to cover the bottom and make it air tight.  The bubble wrap was an awesome idea and after a month of seeing my newly potted seedlings struggle and start to decline I think they will be growing again very shortly in this new set up.

Farmer D

Nice job, Darren. Looks pretty good, too. Have you placed a thermometer inside yet? Probably warm in there, maybe even hot. Be interesting to know the high in the day and the night. Anyway, I bet it works to keep the seedlings growing well until you can put them outside in the sun.

Charlie

Looks great, Darren! 

I was wondering if oxygen build up can be a problem in a small and rather well sealed set up like I have?  I purposely left a few small spots for air to filter in but as I add more plants could this become an issue?

Just wondering...

Farmer D

I think Cris talked about this the other day[air circulation] and Charlie nailed it for me, I was growing my seedlings in a large Tupperware box with the lid shut, I was doing it to retain moisture, I know you are sealing for a different reason but Charlie says not a good idea, I just removed the lid but I expect you will have to find a balance, sort of how many holes you can have without losing to much heat.

In theory, you could get a shortage of carbon dioxide as the plants use it up and expire oxygen. Greenhouse growers in the north US and Canada supplement with co2 gas during winter when the greenhouses stay closed up all the time. I think all you need to do is open the growing space up once or twice a day to change the air for fresh air. There are some other tricks that pot growers use when growing in enclosed spaces like placing dry ice or a yeast culture in the space. I doubt its very effective and not worth messing with for your situation. If you really want to add co2 you need a regulator, a meter, and a tank of co2 to release at the right rate into the space. But, just open the space up to fresh air occasionally and it should be fine.

Charlie

Charlie thank you for the information regarding oxygen build up.  The reason why I asked is I'm contemplating what I should do when I go out of town for two weeks end of May.  Obviously I can't leave my gh rack alone in my home.  Also if it goes more than a day or two without someone opening it up I am looking for potential issues that may arise.  I guess first move is to place it outside in the shade when I'm gone and then find someone who can mist my plants every few days.  I'll still have my three heat mats hooked up to keep it warmer than the outside.

I just got my digital thermometers a few days ago and so far I'm seeing a temp range of 76F - 84F with a consistent humidity of 77%.  Sounds good to me if I'm a baby seedling.  If anyone has any tips or things to look out for please let me know.

Farmer D

Darren, your plan sounds good for May. The temps you are seeing inside the grow area are pretty close to perfect right now. I'm pretty sure the results will be to your liking. For humidity, you need to keep it below 90 percent to avoid problems.

Charlie

I just upgraded my lighting set up to two 2ft 4 bulb T5s.  The T12s I had on top originally just wasn't nearly producing enough light.  Also the bottom now doesn't have to share the light of one lone T5 outside which was causing the plants to face too much to the light and start to grow a little crooked.

Interestingly the temps have now jumped up as well, 90-95F with 61% humidity.  I'll be watching them closely.

Farmer D

Sounds really good, Darren. That should be plenty of light now and the humidity is perfect.

I came across this product recently. Not sure who would buy one of these but if you continue to "upgrade", then here is one version of the ultimate grow container. http://www.growtainers.com/

Charlie

Looks good Darren.  How much have you noticed your monthly electric bill increasing?  I've thought about indoor lighting, but have been hesitant due to utility costs.

Thanks Charlie and Jordan.  It's only been one day and I'd swear I'm already seeing a difference in my seedlings.  Only problem is I'm going out of town this weekend and wonder with the increased heat if my plants will dry out and be in big trouble when I come back Monday night?

Jordan as for the utility bill I have noticed an increase but that could be from the rates going up which seems to be a constant lately.  I did check the meter in the back and noticed that the little arms were spinning so fast they were a blur ;).

I can laugh for now at least!!

Farmer D

I've noticed that too--  not sure if you guys have PG&E down there but whew, this winter has been a tough one here in northern CA for utility costs.

Could you put your lights on a timer, Darren, so they switch off periodically while you're gone?  How about a small fan?

Darren, just make an opening in the plastic to let some heat out for while you are gone. It's better to be safe than sorry in situations like this.

Charlie

So I decided to more heavily water all my plants and leave the greenhouse rack closed up for the four days.  Turns out that was a good call as the soil was getting kind of dry.  Humidity was still good in the 70% range. 

Jordan I was thinking the same about a timer which I ended up using one from my xmas lights which worked out fine.  Now I'm wondering what is a good course of action going forward.

Before I would manually shut off my grow lights but leave the heating pads on 24/7.  With the timer now attached it turns off everything for 8 hours including the heating pads at night.  Do young seedlings need heat all the time or is this good for acclimating them for eventually living outside free of artificial conditions?

Farmer D