Approximately six months into building our urban garden, we have been very quiet over the last few weeks as we assess the progress and short-comings of the plan and adapt our stategy to the location and climate.
Between pests, extreme heat, and an inconsistant supply of water the initial plantings have seen more downs than ups. The eggplant has been battling spider mites all year and produced only 4 or 5 fruits while the snake gourd and pumpkin barely clung to life, in the end yielding no fruit at all. The poly bag towers were successful structures for one season but lasted only a short time in the baking sun, making them a poor options for varieties like eggplant, peppers, and tomatoes which last much longer in the tropical climate than their temperate annual counterparts. So, as we sweep up the dirt escaping the crumbling bags, we have been researching and planning new structures for the next season.
What we learned
Poly bag towers are better suited to shaded and more temperate settings if we plan to use them for more than one season.
Eggplant, peppers and tomatoes can be pruned and coaxed to produce much longer in the tropics.
At least partial shade will need to be provided on a rooftop garden in order to grow a wider variety of edibles.
Just because a variety calls for sull sun on the ground does not mean it can handle full sun on a rooftop.
More insulation needs to be provided to keeps roots cooler.
Composting in a small space is really a simple but critical component of the urban garden.
Moisture-sensitive varieties will struggle without regular care.
Carrots and herbs did surprisingly well in the heat and containers, but the local soil needs more supplementing for best results.
The next steps
The tower growing systems worked well for our space but we plan to improve upon the poly bags by incorporating the plastic drum towers and wooden towers. We are also experimenting with making the towers taller and slightly wider to increase the growing surface area and the insulation for sentive roots.
The eggplant, tomatoes, and peppers – especially the local varieties – have done the best overall and will be up-potted to allow them to produce for another season. More local varieties are being added including Ceylon Spinach and three varieties of citrus.
An arbor has been added with a poly shadecover fabric, but the sun is still quiet strong at certain parts of the day. We will be reinforcing the structure and adding either a passionfruit or other fruiting vine to decrease the heat. This will cover a little less than half of the growing area and hopefully help to cool the room below. The citrus trees will also help as they develop.
Though the compost did well and produced a rich fertilizer in time to help save the mite-ridden eggplant, working with one small bin was difficult. We plan to try a 2- or 3-bin system next to make turning and harvesting the finished compost easier.
Self-irrigating planters will be added for the varieties particularly sensitive to inconsistent water supply. We do have a water source on the roof but try to primarily rely on the rainfall. However, while an in-ground garden will have additional means of water retention, a rooftop system will need artificial reservoirs added above and beyond the all-important mulch.
The local soil collected around the house is quite fertile but also rocky and stunted the growth of the otherwise flourishing carrots. This soil will be ammended with our own compost and local materials to make it softer for root vegetables.
Finally, the garden is not very pretty. While we always encourage re-using materials, we know this does not mean it has to look shabby. Now that the technicals have been adressed, we would like to spend more time on considering design and aesthetics to suit everyone in the household and the urban environment. As we enter this next phase, we will be sharing techniques and all building plans with you, as well as the design inspiration we collect along the way.