Ever since I wrote this post, comments and queries have been pouring and the response is really overwhelming. Thanks for all that.
Questions were mostly of these categories, broadly
- Is greenhouse really necessary. What’s wrong with plain Terrace.
- Planning and cost of the greenhouse.
- Managing plants in greenhouse, ranging from light level, irrigation, pollination , humidity etc.
For the first question, the answer is a big NO. One doesn’t need a greenhouse to start growing vegetable and If you want to start a veggie garden in terrace you can do so without a greenhouse. Then why on earth did I build this whole thing?. Several reasons.
- Protect the plants from the wind. In my terrace, especially in the evenings the wind is at high speed and carries whole lot of dust along with it. Pots with light medium such as cocopeat can’t handle the wind.They simply fall.
- Protection from scorching sun. Bangalore weather is pleasant most part of the year but the it is hot enough to evaporate all the water that a pot can absorb. This makes watering the most important routine in your life. Sometimes You need to water the plants twice if they are kept in open sun. No matter what, if you fail to water single day, a drooping plant awaits you the next morning. Needless to say the yield takes a huge hit.
- With the shade net in place, you reduce the water loss through evaporation and also you can grow veggies that need partial shade/less sunlight. I have lettuce growing in the terrace.
- Protection from birds. Sometimes, birds are a menace too. I have lost many cherry tomatoes because of birds.
- Greenhouse framework gives lots of options to trellis the plants, train tomatoes etc.
My idea initially was to find a neighboring plot of land and construct a greenhouse or something similar. There is beautiful fenced 60×80 feet land, right next door, fully occupied by weeds/shrubs. I called up the owner of the same and checked with him if I can grow some veggies in pots in his land and I would pay some nominal rent for the same. The response was “I don’t have any intention to sell/rent my plot. Please don’t call me again in this regard”..Bummer. My plan B was terrace.
The stairs you see below is the only way to access so much of space available in the terrace. The entry to this space is behind the stairs and that gap between the stair and wall on the left is so narrow that pots of bigger size wont come in. On the right side of the stairs, is what you don’t wanna see. You are on the 5th floor and its quite scary to the ground from this point. While climbing the stairs, I tell people, not to see on their right. Few don’t come up just for this reason.. And for me, this is a good thing. I get less intruders right!?.. 😉
Now that Terrace is my only ray of hope, I started planning for a greenhouse/shade house keeping in mind the following things
- Protection for plants against winds, scorching sunlight, rain.
- Water management ( Irrigation , Drainage)
- Protection from pests, birds etc.
I spoke to few people who deal with greenhouse and either their quotation was very high or they simply did not deal with shade houses of this minute size. So I decided to do it myself. I spoke to few metal structure fabricators and they gave some advice on the kind of metal structures that can be used to build one on a terrace.
After having negotiated on the price front, the work started.
Before proceeding further, I would like to warn that the price figures you are going to see will cause little uneasiness and hence if you are weak hearted, pregnant or having any health condition please proceed with caution ;).
Here are the list of materials needed.
- 2.5” Metal tubes (Gauge – 14) : 10 Lengths [ One length = 20 feet]
- Price per length is around 650 INR. Depends on the price per kg for Iron.
- 40×20 rectangular tubes (gauge16): 10 lengths
- Price/length INR 390.
- 3/4 inch Square tubes (Gauge:16): 11 Lengths.
- Price/Length INR 250.
- 1 1/4 L angle: 8 Lengths.
- Price/Length INR 260.
All this put together it came around INR 14000.
The metal tubes are erected on the terrace with the help of Anchor Bolts. You get this in almost any hardware shop. On Day 1, the metal tubes were cut in lengths of 8 feet. I made this greenhouse in such a way that it is 9 feet in height on one side and slopes down the 8 feet high on the other side. I got a the roof sloping on one side. Though it is not much useful with shadenet, it will be of use if a polysheet is put on top.
After the pillars were bolted to the floor, the top of the pillars were connected using #2 – rectangular tubes. The picture will describe it better. Sorry about the shabby drawing. The circles are the pillars and the thick lines are #2 rectangle tubes and the dotted lines are #3 square tubes.
Once the whole framework was completed, it was time for the concrete work. The point where the pillar joins with the floor was chipped a little and was filled with concrete 9” high. This prevents water from getting into the holes that were made for the anchor bolts.
The total cost, including the labor and purchasing of all other misc items required for the work came to a whopping 25K. As usual I now feel that I could have got the costs down, by reducing on the materials or their gauge.
Now, the finished greenhouse had to be covered. I went in search of Shade net. Lots of reading, calling people, and visiting places happened. I decided to put 35% shade net. Very few shops stocked 35%. I picked up a bundle ( 4mX50m) from a shop in J.C Road for Rs 15 a square meter. Along with it, I purchased a bundle of U.V Stabilized stitching thread to stitch the net where a joint is required.
Covering the whole greenhouse with shade net was a mammoth task. We spent a long weekend to finished. My whole family participated ( Did they have a choice?) in building of this and at the end of the weekend, we were so tired but the sight of the finished greenhouse was a pleasure.
gg, would the greenhouse also protect the plants from monkeys? Right now I can grow veg only on my balcony, enclosed with a grill, because the monkeys take everything edible in the open part of the garden.
Never had monkeys visit my garden and I hope they don’t in future as well. As long as they dont tear off the net, the net wont let them in.
I cannot justify myself spending this much on a greenhouse. I will probably start of with a smaller area and look for cheaper materials etc.
Is it necessary that it has to be 9 ft high? Can it be lower?
I am growing four hydroponic tomato plants in a 12 liter container. The nutrient solution used to last about 2 weeks before I changed it. These days it lasts no longer than 4 days. I am not sure if it is the heat or growth of the plants (they are currently fruiting) or both. If it is heat then I will have to go for shade.
Starting with a smaller area makes sense.
It need not be 9ft. 8ft is more than enough. A mature tomato plant can take easily a liter of nutrient depending on the heat. Keep us posted on the progress. Is it NFT or Deep Water Culture?
It is DWC. Is it one liter/day/plant? Actually I wanted to go with PVC pipes Ebb and Flow but before I could figure out the piping, fittings and accessories I happened to visit a distributor of large tubs. Hence, I am going to setup few more DWC setups (3 of 60 liter capacity and 3 of 45 liter capacity) for Capsicum, Watermelon, Lettuce, Spinach, Brinjal & Okra. I currently use different formula for each of the Tomatoes, Spinach and Cucumber (cucumber has flopped – got only one cucumber ). It is becoming a chore refilling the nutrient solution every other day.
I will have to study your design in detail once again. I am planning to setup a much smaller area, may be around 15ft x 10 ft. I will get back to you for some suggestions and help.
I have a aggregate based setup and I have to some times irrigate the plant twice per day when the plants are so tall and bearing lots of fruits. It will easily take more than a liter per plant per day. It also depends on the transpiration rate.
I have another question. Do you aerate the nutrient water? if yes how? Do send a link to the pics of your setup.
I am using an aquarium air pump that runs 24×7 (it consumes 2.5W/hr).
I am now looking for a more powerful air pump that can run 24×7 with multiple outlets (or use T joints).
I haven’t taken any recent photos. I will send the new pics in a day or two.
I can stand by your words about scariness of looking at the ground from 5th floor atop a frail stair 😉 surely not for the weak hearted!
I can imagine the kind of hard workthat must have went into making this dream a reality. Congrats again! although the costs are li’l high, sometimes no cost is too high when one is chasing one’s dream.
Keep up your good work. I have sowed the lettuce seeds and eagerly waiting.
I still warn anyone who wants to see my greenhouse about the stair 🙂 and it also keeps strangers away. Hope you haven’t buried the lettuce seed too much. It comes up in 3 days.
Hey gg! the lettuce just started coming up from 3rd day onwards. Thank you so much again.
Regarding your post “My idea initially was to find a neighboring plot of land and construct a greenhouse or something similar. …. Please don’t call me again in this regard”..Bummer. My plan B was terrace.”
I feel strongly about this topic and have been thinking about this for quite some time now. So, here is my view. I believe the laws and attitude towards land in India is such that someone will have to be really dumb enough to offer/rent his land to a stranger, he doesn’t know and trust. So if you ask me, the answer from the site owner was along expected lines. Having said that, do I think this problem has a solution ?
Yes, I believe so. For example, if the site owner had to deal with a co-operative or some kind of org. which manages the complete transaction of
1. taking the land on rent.
2. Keeping it maintained, ensuring no illegal activity including any construction happens there.
3. Gives him complete faith (along with a legal framework) that the land will be available back to the him at a very short notice.(2 weeks??)
4. His land will be relatively safer from land grabbers etc etc..
While mentioning the above points I have just done some loud thinking in terms what I will look for as a small site owner if I had to weigh the option of giving my small piece of land on rent for gardening. Of course it would also make me feel good about giving others a chance to spread greenery on a land owned by me but with no immediate use for.
Can the govt play a role in this? Sure, if BBMP can make it mandatory and give instruction, to plant at least two trees in a site of size less than 2400 sft (http://www.thehindu.com/2009/12/17/stories/2009121760890400.htm) then why not frame some rule which makes it mandatory for the unused site be handed over to such org/co-ops for gardening.
Along with the obvious benefits, there will be host of other benefits to the community like cleaner city, lesser neighbourhood garbage dump issues, chemical free veggie available in neighbourhood (may be available for free to the gardener).
Oopsss!!… i think am just getting carried away… will hold there. May be this deserves a post on my blog with the idea articulated more clearly 🙂
You are welcome and I am glad those seeds germinated as i promised 😉
And for the response that I got from the landowner, I was kind of expecting the same as these kind of disputes are quite common in real estates. People say they want to farm and slowly encroach the whole area. Its an issue especially when the owner is staying far away. Also there are other issues, even if the landlord agrees, things like water source, power source (if needed) and all.
UK has something called “Allotments” which is a piece of land given for nominal rent by Govt for gardening. Our govt can come up with something similar.. I think might take sometime but its definitely possible.
Waiting for such a post on your blog….
Lovely tomatoes in your greenhouse.Last time I had written about asphids attacking my hibiscus plant.I had applied neem oil with few drops of liquid detergent but they reappeared after a few days.White snowy asphids are under young leaves .I removed them with freshwater but again they reappeared.Kindly suggest some other remedies to control asphids.My rose has got basal canals and I got three roses this month though the size was small.
Thanks. Like another reader suggested, you can try using rubbing alcohol or surgical spirit with a cotton on those insects. You can mix 50:50 spirit and water to start with. If you add some water soluble fertilizer or a good quality compost the bloom size will increase. Ensure your rose plants get good amount of sunlight.
I moved all my rose plants to the terrace where the receive full direct sunlight and they are so happy they keep blooming and the blooms are like mini lotus.. will post pics soon.
If what you have is a mealy bug then I guess that is bad news, at least based on my experience. I had the mealy bug infestation on my 2 year old hibiscus. I had applied malathion and dimethoate spray. While the bugs are controlled for a while they used to reappear and started spreading to other near by plants. Finally, I had no option but to chop off the tree. New shoots keep coming back from the base of the tree trunk as I was not able to fully remove it. I keep cutting off the new shoots.
I think there are probably varieties of hibiscus that are more tolerant. My other hibiscus plant that is about 15 feet from the infested one has no sings of mealy bugs and produces about 10 to 15 flowers everyday.
Here are some links I found via google that might help you.
BTW, how old are you roses?
step 1 to fixing a mealy bug problem is fixing your ant problem.
get some ant repellent & put it on the plant like a belt so that the ants cant climb up the plant.
I agree with Anil here. Also, don’t crowd the plants. Ensure the ants cannot climb up and as well as from other plants through leaves/stems.
Ants come to eat the wax on the body of mealey bug or the oily secretion from aphids. Are the Ants harmful for plants?
The problem is that it(ant) brings along few aphids/mealys along with it and helps spread their eggs as well from plant to plant. Presence of ants is also a possible indication that aphids are present too..
Thanks GG, now I can correlate the increasing population of aphids and ants in my garden. I will follow the step 1 as suggested by Anil – Control Ants!
Ants farm the apids & mealy bugs, the ants get honeydew as reward.
if you have a spider mite infestation, keep an eye out for ants
the spider mites take a ride on the ants, the ants do not get anything in return though
I have only recently started reading your blog (excellent BTW). I have also recently started gardening on my terrace (1300 sft), but currently only < 100 sft in use so plenty of scope for scaling). The terrace gets full sunlight throughput the day, which at first I thought was a blessing but now am thinking is not so much given the heat in mar-apr-may in Pune. So I am thinking of using a Shade net and I have a few questions
1. What is 35% – is it the amount of sunlight blocked or admitted?
2. Given so few shops keep 35% netting, it means that its not in common use, so why did you chose it? Any specific reason?
3. Is it advisable to have the netting from sides or only on top would suffice?
Hope you can answer and help a novice gardener.
Great to hear that you started terrace gardening.
1. 35% is the amount of sunlight blocked.
2. Not many people grow veggies under shade net. Mostly it is used for nurseries ( ornamentals or raising veggie seedlings). For this purpose, 50% is recommended. Since most of the seedlings directly go into the open field, 35% is rarely used. In my case, I am growing all these veggies under shade net. Having it in the terrace, I want all the sun I can get but in a controlled way. For this 35% sounded just right. If I need more shade, I will use a double layer ;).
3. I use netting all the sides. Generally, it is advised that greenhouse be covered with IP (insect-proof) net on the sides and shade on the top. I didn’t want to invest on IP net and so want with shade net on all sides. Works for me!.
thanks a lot. why? today i was planning to go for a training in simplyfied hydroponics by ISH. at about 5 O clock in the morning, i happened to visit your weblog.!!!! when i read about the bitter experience the other people had for ish i dropped the idea of going for the training. our friends through this blog saved my hard earned money. dear gg, can u give a small introduction in hydroponics because i am very much like to learn it.
You are welcome. I am planning to write an article on how to get started on Hydroponics soon. It will be posted here once it is ready. Watch this space…
We can reduce the cost of iron green house by using Bamboo green house. Did you analyzed of using Bamboo for constructing green house?
No I didnt analyze the cost with using bamboo for support. I am sure it reduces cost by multiple times.
it is very interesting going through your posts.
Nice post. Happy to see such initiatives.
Where do you get the nutrient solution?
hi gg,im planning 2 cover my kitchen garden which is on t ground with shade net…wil 35%one do?wil t yield b normal?and a verry basic q…il hav to remove t net in rainy season right?i live in udupi…pls reply..thanks in advance..
Yes, sometimes birds are a menace, but I couldn’t resist them…
Have a look: