Growing Salad Greens on the Balcony
Some Tatsoi sharing a container with Freckles Romaine and Arugula.
Lettuce is suppose to be one of the easiest of garden vegetables to grow and yet it's something that I used to have trouble with. The weather always seems to be too warm or too cold and windy. Over watering caused rot. Soil compaction and lack of light were always a problem. And when I did get plants to grow to maturity the leaves always taste bitter, likely due to inconsistent watering (because I'm lazy). It's not that lettuces are hard to grow, it's just that I don't get along with them I suppose. But I have found ways to make things work for me.
I find the best time to eat lettuce and several other salad greens is when they are young. Baby greens make wonderful salads. It doesn't take long to get lettuce plants to grow to a size appropriate for baby leaf harvesting - a couple of weeks after they break the soil surface. The beautiful thing is that you can cut a few outer leaves and leave the younger inner leaves to grow a little more for the next round of salads. It's called "cut and come again" and the trick is simply to leave the young inner leave around the heart of the plant so it can continue to develop. Just remember to always harvest early in the day before it gets too hot outside since the leaves will loose moisture and wilt in the heat.
Depending on your level of patients, you may opt to just trim the entire plant when ready and plant more. You could use a couple of containers and stagger plantings so every week a new container would be ready for harvest. But one problem I've found with this is that not all varieties will be ready at the same time. Greens like Mizuna, Arugula and Mustard which make wonderful complements to baby lettuce leaves, grow fast compared to something like red salad bowl lettuce. You have to experiment with different varieties to see what works for you in terms of harvest time and taste.
If you are starting from seed and planning to grow a container of salad greens for use when the leaves are young, you can broadcast the seeds over the soil in a container and cover lightly with more soil. Don't be too fussy about ordering them into rows of other patterns. As the plants grow, thin them out (eating the ones you pull up). You'll end up with nice dense planting but since you will be harvesting when the leaves are only a couple of inches tall it won't matter if things get too crowded. If you want to grow them bigger, thin the plants more to give the remaining plants more space. You can mix your seed together and broadcast the mix into a container but I prefer to keep my varieties separate so a faster growing variety doesn't dwarf and hinder the growth of a slower growing variety.
A couple containers of mixed salad greens off to a good start. Notice how some grow much faster than others.
In this box is Mizuna, Mustard, Arugula, Black Seeded Simpson, Boston and Freckles. All ready for a salad bowl.
Some of my favorite lettuce varieties to grow are Black Seeded Simpson: a green loose leafed variety, Freckles: a green romaine with red-splotches, Boston: a green loose-heading butterhead, and Lollo Rosa: a red loose leaf variety. There are several others to choose from. Basically, the lettuce varieties break down into four categories: loose leaf, oak leaf, butterheads and romaine. Forget iceberg. Loose leaf is very common and oak is just another leaf lettuce with leaves that look more like... oak leaves. Butterheads are loose heading varieties and you'll see names like Boston or bib. And of course romaine is the ever popular tall and crisp loose-heading variety.
Lettuce has a shallow root system making it an excellent container garden choice. The plants like cool weather. When the temps warm up, lettuce will bolt and go to seed. To get the plants growing fast while the weather is cool, feed heavily. Grow them in nutrient rich soil with a tendency towards nitrogen for lush leaf development. Another key to great tasting lettuce is moisture. The plants need a constant supply but not too much. The young plants can be quite delicate and rot at the base easily if over watered. Sunlight can also be a problem. To grow properly they need overhead sunlight which can be difficult to provide on a balcony but at the same time you want to avoid scorching the leaves with too much 'hot' sunlight.
This is what happens to lettuce when the weather gets too hot: it bolts and goes to seed.
I love growing swiss chard. These were from a pack of rainbow chard seeds. All I got that season were yellow stalks.
Other young leafy green plants that work well in salads are Mizuna, Arugula, Mustard, Spinach, Swiss Chard, Kale, Beet Greens and Leaf Chicory (aka Endive). I've grown all of these from seed to maturity in containers on the balcony and have actually had an easier time with these than lettuce, in most cases. Swiss Chard is a favorite. Nice large crinkled leaves on meaty stalks. And it is happy in a wide range of climate conditions. I like to grow it in partial shade on the balcony floor. It doesn't get very big there but that's fine. Rainbow chard or bright lights are common names for a variety with different stalk colours: red, yellow and while.
Another great plant to grow in containers on the balcony is kale. The first few leaves can be eaten raw in a salad but after that it's better cooked. We enjoy the leaves sauteed in a pan with butter and onions but recently we've been adding it to vegetable soups. The admirable thing about kale is its ability to survive cold temperatures. In fact, it tastes better after a frost or two. I've seen it survive unprotected, long after the first snow fall and into the start of winter.
A few times I've attempted to grow radicchio on the balcony and have always failed. It never forms a head and always loses it's colour, quickly turning from red to green. In general I've always had difficulty with red-tinted leafy plants on the balcony and I think the problem is lighting. Only the suniest parts of my balcony provide enough light to get the leaves to turn red. Anything less and all I get are green.