We’ve served up our first home-grown salad! But we’ve had to call on the urban gardening experts for a bit of troubleshooting too…
We’re on a mission to grow our own food and see just what we can do here in Singapore from a balcony! Our friends at Aerospring Gardens are leading the #growyourownfood movement amongst city dwellers with one amazing little vertical garden that involves no soil and self-waters the plants. Six weeks into our urban gardening project, our little patch of green is flourishing nicely. So far we’ve covered how to get started with your own balcony garden, growing herbs and salad greens from seed and now we’re ready to enjoy some of our own home-grown produce. But we’ve also encountered a few speed humps along the way…
But first, hooray! We’ve picked our first batch of leafy greens – and the kids LOVE helping to harvest salad and herbs. Check out our first haul of kale, red amaranth, giant basil and mint. We could get used to this…
It’s worth the work needed to look after a little balcony garden – our daily routine is checking that our plants have enough water, and moving them around so they all get their moment in the sun. Once a week, we check the nutrient levels using an EC meter and add plant food when needed. Of course, with the highs of having leafy greens that didn’t come in a plastic bag, we’ve encountered a few little challenges too, from plants turning from rich green to yellow, and water temperatures as high as 33 degrees. So Nadine Keller and Thorben Linneberg of Aerospring Gardens have stepped in for a bit of troubleshooting – can you tell we’re rookies at this gardening gig?
1. Why are my plants looking yellow?
Yellowing plants in hydroponic gardening is a sign of nutritional deficiencies; usually nitrogen as if you’re growing leafy greens or herbs. If you have fruiting plants in your vertical garden, they could be drawing more of the nutrients and leaving little left for the other plants to absorb. Check your nutrient levels in the bucket with an EC meter and change out the water every month to ensure optimal nutrient levels.
2. Why are my herbs growing on one large, long stalk and not into a bush?
This is because the herbs aren’t being “topped”. Basil grows very quickly and you should start pruning or topping the plant when the central stem gets about 15cm tall and has developed three to five strong leaf sets. Basil branches out at these pinch points, two new leaf sets form at these points and you should continue pinching as the stems on the new leaf sets get longer. When harvesting, continuous use of the pinching method will develop your plant into a bush. Use this method with your mint, too.
3. Why do my tomatoes keep dying?
Tomatoes start getting really troubled when temperatures exceed 34 degrees. A mature and established plant may survive such temperatures, but a young plant may lose the will to live. In fact, pollen in tomato flowers are rendered infertile in such extreme temperatures, so while you may have an abundance of flowers on an established plant, it won’t fruit. If you are cultivating a young plant, note extreme temperature days and move it to a shady spot if temperatures exceed 34 degrees.
4. The roots of my plant have turned brown – can it still be saved?
Root growth is an ongoing process and browning of the roots is normal. If you spot new white roots coming through, there is regeneration which is what you want to see. New root growth is important for the uptake of nutrients as younger roots absorb the nutrients better. Smelling and feeling the roots is also a good indication of whether they’re in trouble; if they smell rotten and feel mushy, there may be root rot in progress and possibly also bacteria. Generally, root issues arise because of an unmanageable increase in temperature which lowers the oxygenation rate of the water. We sometimes manage this by adding Hydrogen Peroxide (H202) into the water tank, but do note the concentration and dilution rate (15ml to 75 litres at 20% concentration). Hydrogen peroxide will help eliminate existing infections and prevent future ones.
5. My balcony is sizzling hot and my plants are getting scorched – how can I protect my plants?
Always rotate plants that receive little to no direct sunlight. If you’re using an Aerospring vertical garden, protect the bucket of water from the sun and monitor your water temperature. The bucket should not be exposed to the blazing sun and if it is, should be shielded with some cardboard, shade netting or even a weatherproof sheet, the kind you would use on the dashboard of your car. Another way to combat an extremely hot day is to keep a couple of small water bottles filled with water in the freezer. Throw them in the bucket on a really hot day to cool down the water.
6. What are these white spots on my plants and how do I get rid of them?
White spots on the surface of the leaves could be a fungus like powdery mildew. Powdery Mildew is a fungal disease that affects a wide range of plants and is prevalent in high humidity climates like Singapore. It often affects the cucumber or pumpkin plants. If you see specks of white on the underside of the leaves, you might have whitefly. If these specks can’t be wiped off, it’s probably fungal. The natural method of treating this would be to use milk (yes, the kind you drink!) in a 1:10 dilution to water. Spray affected leaves and stems. You can use this to treat as well as prevent (spray weekly).
Update: We’ve since encountered a small army of different pests, who’ve travelled 14 floors to get to our plants (clearly our produce is top-notch). Look out for our dedicated post on dealing with pests in the garden!
Want to know more about our spiffy vertical garden? Start from the beginning of our urban gardening journal!