Let Your Containers Do the Watering

By Jane Shellenberger:

Who doesn’t love home grown vegetables? But not everyone has a yard, enough space for a garden, or the ability to stay home every day to water. Especially in the summer, people like to get away once in a while. There are a lot of different and ingenious setups for indoor growing with lights year round now, thanks in large part to the burgeoning marijuana industry, and these may help save us all as the climate continues to deteriorate. If you have no space outside at all these can work for you. But if you have at least a little space, or a patio, sunny balcony or rooftop, these can serve as outdoor growing areas. Using self-watering containers makes it a lot easier to grow healthy plants in these settings.

Growing outdoors eliminates problems associated with poor air circulation as well as the need for electricity. With good quality organic soil and fertilizer, and several hours of sun you can grow almost anything this way, from all kinds of greens and lettuce (which need less sun) to squash and tomatoes, (though you will probably have to provide some vertical support for them). Getting the soil and watering right are usually the main considerations when growing in containers.

There are several good reasons for using self-watering devices and there are a lot of options for purchasing systems or whole set-ups, as well as for making your own. Some show how to create simple, inexpensive set-ups reusing materials like plastic bottles and other containers that you propably have sitting in the recycle bin.

Using good quality soil and getting the watering right are usually the main considerations when growing in containers.

The central concept is to have a reservoir of water that is separated from the soil but allows for very slow seepage into the soil either through a few small drainage holes or by using a wick - soft, flexible nylon rope seems to work best. A strip of wicking material is usually set inside a smaller container of water which is placed either into the main pot/container or outside of it with the other end of the wick placed into the soil. Several plants in smaller ontainers can be arranged in a circle (or however) with a container of water holding a wicking strip for each plant placed in the middle. Some plant roots (“water roots”) will grow down into the reservoirs and may need to be pruned.

“The Swedish Plant Guy” on YouTube uses a volcanic rock gravel underneath the soil in his self-watering houseplant pots, which he says allows water to drain but, unlike regular gravel, retains moisture and releases it again slowly when it reaches 30% capacity.

If you’re not feeling particularly adept or crafty, or if you want something more attractive than the plastic bottle models, there are plenty of other options. Costco has handy large self-watering containers (almost waist high) with wheels so you can easily move them to follow the sun - or the shade as the summer gets hotter. A lot of people like Earthboxes, which include durable ag/landscape fabric “mulch” covers with holes for plants to grow through. Not everyone is wild about those fabric covers so they make adaptations.

A local, home-grown Colorado company that has really raised the bar on aesthetics is FarmTub®. I met Susan Walsh at a garden tour in Boulder when she was just starting her business many years ago. She enthusiastically showed me her small home sunroom with some galvanized tubs and small stock tanks where she and her husband Bob were growing vegetables. Over the years they experimented and perfected their system which now uses a water reservoir that can be easily adjusted, and an adaptable wicking system that can meet various water needs. The plants stay healthy and vigorous with very few pests because the soil surface stays dry and the soil never gets compacted. But what really sets the FarmTubs apart are the beautiful veneers they use to cover the outside of the tubs and tanks. Because of this, landscape designers and municipalities have now become their primary customers, some of whom have added rollers to the tubs so they can be moved around. FarmTub (www.farmtub.com) also offers conversion kits in case you want to use your own container.

Watering Rocks (www.watering-rocks.com) are another option for watering containers, hanging baskets, or trees in your garden that need a long slow drink. These are actually small portable drip irrigation systems with reservoirs designed to look like rocks.

(This brings to mind a wonderful Christian organization called Chapin Living Waters. I read about them many years ago and bought one of their bucket kits. These portable drip irrigation systems, designed for farmers in drought-stricken parts of Africa, are simple, gravity-fed drip irrigation systems, using a five-gallon bucket elevated three feet above the ground. Replenished a couple times a day, the system provides enough water for 100 vegetable plants to thrive, even during long periods without rain. www.chapinlivingwaters.com.)

Self-watering devices can save quite a bit of water that would otherwise run out of the bottom of pots and evaporate. Most plants like to sip their drinks rather than gulp them down all at once so providing long, slow infiltration benefits them while keeping air in the soil around their roots, which all plants need. Overwatered plants die because of a lack of oxygen around their roots. One friend reports: “Strawberries had fewer disease/overwatering problems in the elevated self-watering containers… I plant these very intensively but the reservoir keeps them well watered and I can just put liquid fertilizer right into the reservoir. I can see the little red indicator up from a distance when the reservoir needs filling.”

Self-watering set-ups will also save you time and allow you to go to work without worrying whether your plants will fry on a hot concrete balcony. You can leave town for a few days or, with some systems, up to two weeks without needing a plant sitter. They make it easy for anyone anywhere to grow some of their own food and flowers. The bigger ones are even high enough to keep the bunnies out.