Thursday, January 25, 2018

Growing Corn In An Urban Space

The silks of this ear of corn has been fertilized- they have gone from shiny pale gold to a duller brown.
When you think of growing corn, I'm sure the average person imagines huge fields of tall green stalks waving in the summer breeze, festooned with pollen scattering tassels and golden tufts of corn silk. Even the average home gardener imagines a few rows of corn, or maybe a block of plants in the sunniest corner of their vegetable patch.

Me? I grow corn in a space less than a meter square most years. 

Less than a meter square? You say. That's crazy talk!

I live, as I'm sure I've mentioned before, in a tiny unit in the 'burbs, with a garden space that is maybe 35sqm at most not including the bits I can't plant on, including the footpath and some of the beds that are still filled with gravel. I rely a lot on raised beds and containers to do my growing. I try to be frugal with my garden expenses, so instead of going out to buy "ready to go for you today" pots or beds of corrugated iron, I hunted around and found used brick and concrete blocks to build raised beds, and found people giving away heaps of used plastic tubs, and even, in the case of my three newest planter boxes, went to the discarded pallet pile of an Isuzu dealership and picked up some folding stacking "crates". These new planters were assembled to replace the old wooden planter boxes, which had finally started rotting through and falling apart (after five good years of service, mind you!) and these planters are part of my 2018 corn project. So, let's get down to business!

Tall corn stalks add an interesting
dimension to a container garden
No soil? Make some!
Since the soil in the existing household garden beds was so bad, I spent a good deal of the last seven or so years building up brand new soil through the lasagna composting method- basically, layers of manure, straw and topsoil or compost when I can get it. When I remember to, I add crushed eggshell for calcium, Epsom salts for magnesium and dried seaweed or seaweed emulsion for iodine (Australian soils are notoriously lacking in iodine, an important nutrient for good thyroid health). I also make sure that I have a decent worm population, and try to encourage good microbial life, because all of those things- plenty of organic matter, extra minerals and nutrients, and healthy abundant soil life- are what make the soil the best it can be for your plants. Like us, plants need to have good nutrition to grow properly, and when they are healthy, it means we are benefiting from the nutrients that they have absorbed.

The lasagna method of composting is the easiest and probably the fastest way to build up good soil. I call it lazy gardening- I love it. Just throw your layers down, rake them even, water them well, and walk away. No digging or rototillers required. It all just builds up on the surface, encouraging worms, who then move between the layers and the ground beneath to aerate and turn the lot over and break it down for you. In fact you don't even need ground underneath- one of my raised beds is built entirely upon concrete pavers! The method remains the same though. After a several months or years of this you'll have heaps of great soil to work with, and the best thing is that you can still garden in between applications of your mulches. One of the joys I have found in my gardening journey is seeing how much the improved soil has improved my growing- so if you are the type to journal your experiences, do. It'll show you your progress, which is always immensely satisfying.

Tassels beginning to form.

I talk about all of this, because the first thing you need to know about corn is that it is a heavy feeder- that means it needs a lot of nutrients, as many varieties can grow to be quite large, and they need those nutrients in order to develop properly. You can give it a boost with extra fertilizers if your soil isn't the greatest, but it's easier in the long run if you just take the time to build up good healthy soil in the first place. When I started growing corn, I was putting them directly in the ground before it had seen too many layers of manure and mulch, so the added fertilizer helped a great deal with what was a lack of nitrogen and other key elements. In fact, part of this years project (growing corn in a planter box instead of in the flower bed) was to give me time to amend the flower beds much more thoroughly.

Well, this is unusual. An ear of corn is growing out of the top of this plant
at the same time as the tassels... and appears to be producing kernels!
When and where to plant?

Corn is a summer plant- by that, I mean it will do most of it's important growing over the summer months, and will be ready to harvest sometime in autumn (usually- this depends entirely upon your climate and the length of your seasons, but in Tasmania's cool temperate clime, it's really important to get the timing right). When choosing your location, make sure it has access to a lot of sunlight- too much shade can stunt your plants and affect whether or not they produce. Corn also needs plenty of water, which is another reason why layer gardening is helpful- the organic matter within the layers traps water and helps the bed retain moisture better, which is good for the corn plants. Generally, I try to plant my corn in late spring, after all danger of frost has passed. That advice works for pretty much everywhere.

When starting corn plants, I like to place the seeds in separate pots filled with soil so I can keep track of the germination rates for the varieties I grow. It allows me to judge which varieties are the best and strongest growers. Then, once they have sprouted and form two to three leaves, I plant them out.

What kind of corn?

What type of corn you're growing will be affected by your climate and season length. Check the description of the seed variety you are purchasing, and make sure you know if it's short season or long season. This is important, because if you're trying to grow long season corn in Tasmania without a greenhouse, you will probably be very disappointed. Tassie needs a short season corn. In the past, I have learned that Glass Gem and Mini Blue Popcorn (both popcorn varieties) work well here, as does Painted Mountain Corn (a type of flour corn), along with your usual hybrid and heirloom varieties of sweet corn, such as Golden Bantam or various F1 types. My choice this year is a short season variety called Papa's Red- I am hoping it is successful, as it would mean Tasmania benefits from a new variety of red flour corn that is adapted to our climate, and thus expanding our range of heirloom varieties.

This variety- Papa's Red- has all kind of surprises. Here is an ear of corn that appears to have outgrown it's husk, the protective layer of leaves that normally surrounds a cob of corn.
How do I plant corn for successful pollination?

Now that you know you need excellent soil for good corn growth, you have your ground ready to grow, you have an idea of when and where to plant and most of all, what type of corn to plant, let's talk about rows versus blocks, and how the corn reproduces.

It is helpful to know that corn is wind pollinated- this means that the male flowers (the tassels, found at the top of the corn stalks) release their pollen which is then carried by the breeze to the female flowers (the silks, the golden bundles of thin threads that are located lower down the stalks at the end of the bundle of leaves that will eventually develop into the ear of corn) in order to fertilize the kernels-to-be. The better the pollination, the fuller your ears of corn will be, and when you're growing seed corn like I am, ensuring good pollination is very important. (It also means that corn can cross-pollinate very easily. If you are growing corn and don't want varieties to cross, either grow a single type of corn per year, or grow two varieties that do not tassel at the same time.)

Rows work well if you have a large garden space to work with, and plan on planting several rows (at least three or four). This means there are several plants within reach of each other- it's essentially like planting several small blocks together. However, this isn't always possible if you have a small urban garden. That is where single block planting comes in.

Whatever is happening here, it'll be interesting to see how successful
These kernels will be. As you can see in this photo, they are just
starting to color up.

A block of corn can be anywhere from 9 to 20 plants, it just depends on your space. This year, I had about 32 seedlings come up, but only 20 survived the seedling stage to be planted, and of those, I think about 10 remain (it's a tough life, being a plant). Most garden guides will tell you to plant each corn seedling 1 to 2 feet (30 to 60cm) apart. I simply don't have the room to spare for that much space between plants, so I have learned that you can get away with as little as 6 to 8 inches (15 to 20cm) between the plants. This places them close together which, while it may not encourage them to grow as tall as they might potentially be able to, does a number of things- it keeps them close for good pollination, it helps them support each other in gusting winds (something which Tasmania is prone to receiving in many areas, my garden not excluded), and it saves on space and the resources you need to maintain them (especially when it comes to watering).

The planter box I have mine growing in is about a meter square and stacked three high (altogether, about a meter and bit tall)- maybe a little less than a full square meter, as they are rectangular, rather than properly square. Nevertheless, the corn plants are doing well, and have only needed that first initial application of all round fertilizer to give the seedlings an extra boost (they were looking a little anemic when they finally went into the ground). A bit short, but then, pretty much all of my corn is, and it never seems to stop it from producing well.

Seed corn, drying out on the stalk.
My corn has been in the ground a while and I want to harvest. Now what?There is nothing more exciting about growing your own food than the harvest- it is what you've been waiting impatiently all these weeks for. To pick the ripe produce and add it to your meals is probably one of the most satisfying rewards of gardening. Golden sweet corn, hot and dripping with butter, is enough to make the mouth water- but be sure you harvest at the correct time!

Harvest time depends on what variety you are growing, and for what purpose you plan on growing it for.

Sweet Corn
Sweet corn types are ready to eat when you can peel back some of the green husk and see that the cobs are full of kernels, the kernels are plump and well colored, and the juices, when one kernel is squashed by a thumbnail, run milky white. As my father once told me: "You walk to pick your sweet corn, but run home to cook it". Sweet corn doesn't remain sweet for long as the sugars begin to transform into starches as soon as it's picked, so its best flavor and sweetness will be had if you cook it almost immediately. So harvest wisely and enjoy your sweet corn!

Drying corn inside the house. Dwarf Mini Blue Popcorn pictured.
Popcorn, Flour Corn and Seed Corn
Thankfully these all pretty much fall under the same instruction: be patient. You must leave the cobs on the stalks to dry out completely. If they are mostly dry, but the weather is turning nasty and cold, you can harvest the ears, peel back the husks and braid them together into a rope, which you can then hang to dry in a warm, dry place to finish drying. Generally, I leave it in the airing cupboard and forget about it for a few weeks. By the time I'm looking for something to do in the winter, it'll be ready to shell.

Dwarf Mini Blue Popcorn seeds packaged for sale.
To shell your corn, just remove the husks, grip the cobs between your hands, and twist. The action of your hands rubbing in opposite directions will loosen the seeds. Be sure to do this over a bowl or bucket, or you'll have seeds everywhere! I would advise you to invest in a pair of gardening gloves with the rubberized palms. They will grip the seeds well and protect your hands from blisters, as you do need to apply quite a bit of force to get them to loosen. Once you have shelled all the corn, you can package and store as you see fit. Generally, a cool, dry, dim location is best. Seeds can even be stored in the freezer if you want to preserve them for long term, but for the average gardener growing year to year, a cardboard box in the wash house or garden shed is perfectly suitable.

The leftover dried stalks, the husks, and the empty cobs can all be composted. I like to lay them down over the garden beds as the next layer of organic material. What comes from the earth goes back into it. Pure poetry.

Thank you for taking the time to read this blog! I hope I was able to provide you an in-depth look at growing corn in general, and that my experiences have encouraged those of you living in small spaces to try your hand at growing corn as well. If you liked this blog, please comment and share it with your friends, and then hit the "Follow" button so you can get updates of future blogs!

Thank you once again, and may you never lose your love for Living and Learning!


  1. Love the dwarf blue popcorn. I would love to try and grow popcorn again.

    1. It was probably the most satisfying type of corn I've grown so far- it put on 4-5 ears per stalk! I will definitely try to grow this again, in a much larger block.

  2. Replies
    1. Thank you! It took a few days to write, and I'm still updating it to include the odd bit of info I've missed. :P


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