How do I design a new urban rooftop garden?

April 10, 2005 1:38 PM

Calling all green-thumbed MeFites on the green: How do I make my new (urban, rooftop) garden grow?

My fiancée has just moved into a new apartment in the west end of Toronto. One of its nicest features is a 15' x 8' foot exterior deck off the kitchen. It is on the top (third) floor of an old brick house; there is no roof on top of the patio so it gets a ton of sun nearly all day. Right now it is empty: Not a stick of furniture, BBQ, nothing: All potential.

My goal is to plant a herb garden in clay planting pots and supply the kitchen with all the basil, mint, thyme, cilantro, rosemary &tc that we'll need for the summer time. Maybe a tomato plant or three as an experiment. Since I'm a biology student, I have some abstract knowledge about how living things work; value organic produce; but have no experience growing plants. In short, I'm a total newbie that would appreciate any and all tips, tricks, pointers, webreferences, DIY guides, etc. (Oh, and our dog demands free run on the deck so we also have to think about not planting anything toxic to canines.) Thanks!

posted by docgonzo to Home & Garden (12 answers total)

Oh, I used to grow tomatoes and jalapenos on a north-facing balcony in downtown portland, oregon. You should have a much easier time than I did.

The big thing is sun, dirt, and water. Herbs are really easy. I'd use plastic pots rather than clay, though, they're easier to clean out at the end of the season.

To get set up, buy some potting soil. Put the soil in the pot. Put the seeds in the pot. If the soil gets dry, add water. If the soil is wet, don't. You might need to cover the herbs with some wire or something (inside a cage?) to prevent birds from eating the herbs or seeds. If you get bugs or a plant disease, google the symptoms and it'll tell you how to fix it. (I had problems with aphids, and fixed it by going to a nearby park that had a lot of ladybugs, kidnapping some, and releasing them on the plant that had the problem.) If things start to grow slowly or yellow a little, try some Miracle Grow. Be careful and follow the directions, because too much Miracle Grow can actually burn the roots and stunt growth.

Since you're in toronto and your growing season is short, I'd suggest starting the plants indoors on a windowsill in itty bitty pots -now-. You can transfer the seedlings once you're not at risk of having a frost anymore. You can also accelerate the growing in the seedling phase while the plants are indoors by putting saran wrap over the top. Just don't keep it TOO moist and make sure they get enough light, or you'll get mold growing on the dirt. ;) (Or maybe that's a portland thing, mold even grows on people here if they stand in the shade a few minutes too long.)

With herbs, you want to selectively harvest... thin the herd, but don't completely kill off any one patch or frond or whatever. If you wanted to do longer trays, I'd suggest salad greens like spinach as well.

For starters, I'd suggest basil, parsley, chives (great on baked potatoes!) and oregano. This gives you the basic herbs that many italian and american recipes call for, as well as garnish. All of them are easily dryable if you hang them in bunches from a string from the kitchen ceiling next winter, and none of them should be toxic in any way. I'd also suggest growing something like a tomato plant in a big pot (you'll need a cage for it, too) because I love the smell of tomato plants and you can use fresh tomatoes on anything... you'll definitely need to pick a "short growing season" varietal and start it NOW indoors, though.

I don't know what kind of dog you have, but most dogs I've seen have avoided herbs because they smell too strongly.
posted by SpecialK at 3:01 PM on April 10, 2005

I do this very thing on my deck - I grow tomatoes, strawberries and herbs in about a 4x6 space that's occasionally shared with our indoor cat. Since it's late in the season, you'll want to buy your seedlings now instead of trying to grow from seed, which makes the process a lot easier.

First off, chives, basil, oregano, thyme, lavendar and dill all grow really well in full sun (my experience) and I'm trying rosemary out this year. I would get either a strawberry pot with nice deep cups for your herbs, or seperate terra cotta pots. Right now I have basil and oregano in one larger 12' diameter pot, and rosemary in its own small 5" diameter pot. I grow thyme in a wee plastic windowbox salvaged from one of those Martha Stewart kits you can get at Kmart. My strawberries are not in the strawberry pot, but in their own 12" diameter pot. Same for my tomatoes. You'll want a tomato support in your pot before the plants get too big.

Start simple - pick four or five herbs, and two fruiting plants (inc. tomatoes). Get basic potting soil from your local garden center and transplant your seedlings. I use tomato spikes for fertilizing my tomatoes, but I do not use fertilizer on my herbs. The key to keeping them alive is to keep them nicely watered. Container plants need more watering, usually daily in the hottest months. Make sure your pots have drainage holes in the bottom, so that the roots of your plants don't sit in stagnant water if you happen to overwater one day. You can also add a fine layer of gravel to the bottom of the pots for plants that love drier or sandy soil.

Here's last year's garden

We had a great crop of tomatoes last year. About three times during the season we scooped a handful of mixed coffee grounds into the tomato pot to make the soil a little more acidic. They seemed to love it.

Good luck!
posted by annathea at 3:02 PM on April 10, 2005

I don't recommend using Miracle Gro on anything you intend to eat unless it's specifically formulated for fruits/vegetables/herbs. It alters the flavour and is not very good.
posted by annathea at 3:04 PM on April 10, 2005

annathea: Sorry, forgot to say that I use the Tomato Plant Food
posted by SpecialK at 3:23 PM on April 10, 2005

SpecialK - ah, that makes way more sense. :) I used that two years ago, got great results from it. This year I'm trying the spikes due to a crazy schedule - I'm very likely to forget timely fertilization, so, I am cheating.
posted by annathea at 4:41 PM on April 10, 2005

Tomatoes are some of the most rewarding plants for that type of set up. They aren't too hard to grow and give a nice bounty. The plants grow best with a lot of sun, also, we have found that putting red paper around the plants seems to help them put off a lot of fruit.

I would suggest also figuring out what you are going to do for pest control early, before you get bugs. Find something you are comfortable with, organic or not, and spray the plants with it. It's easier to ward bugs off than it is to get rid of them after they have arrived.

Snail bait works pretty well on those critters and also doesn't go directly on the plants.
posted by jonah at 4:42 PM on April 10, 2005

Buy this book, published just last month. It's full of fabulous tips, photos, instructions, and is aimed towards the young urban (nominally female, but anyone really) gardener! It talks about planting on fire escapes, public lots, where to find cheap plants, how to start from seed, etc. Awesome book.

And I too suggest tomatoes, as long as you remember to water them often. The smallish bright red homegrown ones are soooooo much better tasting than the big bland watery orangish softballs they sell at the supermarkets.
posted by Asparagirl at 6:46 PM on April 10, 2005

I agree with SpecialK on just about everything, but if your experience in growing stuff is small, start out buying seedlings rather than seeds. You bypass the initial sprouting phase (if you buy seeds and some don't sprout, there could any one of a hundred things responsible, whereas seedling death is usually easy to diagnose) and are more likely to get a successful crop.
posted by Ritchie at 7:44 PM on April 10, 2005

I'm surprised nobody else has mentioned this book yet: The Bountiful Container is a great reference to this kind of gardening, and a great confidence booster as well -- it emphasizes how container gardening is in many ways easier than traditional methods.
posted by xil at 8:41 PM on April 10, 2005 [1 favorite]

If you look into one of the online sites on container gardening, or check out one of the books, you'll find information on growing mediums (ie dirt). I'd like to emphasize that the weight of dirt can be considerable, and wet dirt even more so.

Weight tolerances of balconies are fairly high, but not unlimited. It would also be wise to consider where the runoff from watering is going to go.

Enjoy.
posted by reflecked at 4:32 AM on April 11, 2005

I garden on the roof of our building entrance in Budapest. Easiest are chives, mint, basil, thyme, savory. For most herbs you don't need a very large pot, and plastic containers will work fine, but larger pots will let you go away for a week in July without worrying about coming home to dead plants. We also grow rucola, hot peppers, and shiso successfully. I've found that growing snow peas, various greens, or tomatoes on our rooftop container garden doesn't produce the amount of veg to justify the effort and expense.

Try and add some perlite or lava rock and clean sand to potting soil to keep it from getting too dense and packed as the roots spread in June. Roots need air too.
posted by zaelic at 4:33 AM on April 11, 2005

I've grown herbs and tomatoes on a roofless patio in Toronto (King & Jarvis) for a few years now, so I guess I have a couple tips (and feel free to e-mail me if you'd like more info or need a garden buddy). I'd say my biggest problems have been too much light and wind off the lake.
Both of these effects are incredibly drying, so I found that I need to water nearly every day once the temps get above 20C. Try to water in the morning - it's more efficient. Also, because things do dry out so quickly, you may want to think about plastic or fibreglass pots which will help hold the water a bit better. Another benefit of non-clay pots: they won't crack in the winter. If you leave a clay pot full of soil out in the winter, you won't have a clay pot the next summer!
I would suggest buying seedlings instead of starting from seed, the local Loblaws will have pretty good prices and should have a decent selection. Cherry tomatoes grow really well in containers (Tom Thumb is a good variety) but some people have success with roma (plum) tomatoes. If you are going to grow beefsteak, they'll need lots of water. Tomato plants don't like water on their leaves, so make sure you water the soil directly.
Some herbs are perrenials (mint, chives, etc.) so if you plant them in a nice fibreglass pot, they might last through the winter!
posted by nprigoda at 6:54 AM on April 11, 2005