Bob Hyland is a man who is spreading the word about a plant growing system called Sub-Irrigated Planters (SIP). Hyland thinks it's the perfect way to grow plants in an urban setting, especially if you are growing crops, and I am curious to know what you think of the system and the reasons to use it.
By putting a water reservoir at the bottom of a planter (as shown above), plants have steady access to water and nutrients. The reservoir keeps the water contained yet accessible to the soil as it draws only what it needs up to the plant roots. One look at Hyland's blog, Inside Urban Green, and you can see how passionate he is on this one subject. Here are his main reasons for advocating SIP systems in cities:
- Nutrients are not washed away as they are with conventional planters and watering.
- Up to 90 percent of the water put in is used by the plant, rather than lost through the drainage of a conventional planter.
- Since water is contained in a reservoir and does not drain out or evaporate, these systems need far less watering.
- Plants can access the water reservoirs as they need, which helps plants deal with the extremes of heavy sun and heat.
- By drawing water up from the bottom, the top of the soil stays dry and reduces the occurrence of certain garden pests.
- The contained system is perfect for gardening in areas with contaminated soil, which is very common in city plots.
With the amount of water conservation alone, the system seems more effective than even soaker hoses and drip irrigation. What I am not a fan of is the amount of plastic these systems seem to need in setting up. But this is offset considerably by the ability of a SIP to produce the amount of crops and conserve the amount of water that it does.
You have most likely seen the Earthboxes and Growboxes that are now commercially available, which are made of food-grade plastic and have a water reservoir below the layer of soil. But beyond the hype of these readymade systems the technology is quite simple and Hyland's blog shows ample examples on how anyone can experiment with this type of watering system.
This year my tomato plant looked like it was doing jumping jacks as I tried in vain to keep it steadily watered on a sunny roof. I have no doubt that the SIP system would have been a considerable help.
Brooklyn Based recently had a presentation by Hyland, and wrote a fantastic article of the event for those of us that could not attend. Frieda Lim also spoke about the garden she built using SIPs (shown below) and how successful her rooftop plot has been.
Matt writes a weekly column on plants, flowers and gardening. Feel free to e-mail questions to firstname.lastname@example.org