Thinking about growing your veggies in a self-watering container? We tried it last season with mixed results. Here's our story.
Joe Provey, Home & Garden Editorial Services
Last year my wife and I, both experienced gardeners, planted in self-watering containers for the first time. Self-watering containers
typically consist of a plastic container
, a water reservoir
at the base of the container, a perforated "false bottom"
that separates the reservoir from the soil, and a fill pipe
that leads directly from the top of the planter to the reservoir.
The black plastic "false bottom" seats over the reservoir. The fill-tube at top has a cap to keep insects out. Perforations and a cotton wick move water from the reservoir to the potting mix.. Photo: Joe Provey, Home & Garden Editorial Services
rests on the false bottom and absorbs water from the reservoir via evaporation and capillary action. Some self-waterers also have soil channels
that contact the reservoir and absorb water. Overflow holes
keep the reservoir level to a few inches high and prevent the potting mix from getting waterlogged (if you're lucky, your container comes with overflow holes pre-drilled). Some self-watering containers include support systems
for tall plants, outriggers
for planter stability, and fabric mulch
that snaps over the top like a shower cap. Virtually all types of planters, from pots to window boxes, are now available with self-watering features.
The supposed appeal of self-watering containers is not having to worry about over-watering your plants -- or forgetting to water them enough.
On some self-watering containers, you must drill the overflow holes yourself. Photo: Joe Provey, Home & Garden Editorial Services
Sounds pretty convenient, huh? Well, it wasn't the cure-all we'd hoped it would be. Put it this way: this year we're back to our regular pots and planters. It's not that self-watering containers don't work. They usually do, and many gardeners swear by them. But my wife and I have decided they're not worth the trouble. Here is our list of gripes about self-watering containers.
1. They make container gardening a bit more complicated than necessary.
We found ourselves needing to deal with water-level gauges, container bonnets (plastic, mulch-like barriers that separate the standing water from the soil), fertilizer packs, flimsy trellises (they come with the container if you buy one ready-made; otherwise you can DIY your own self-watering container
), and the biggest slugs we've ever seen (they're drawn to the standing water; we're lucky the mosquitoes weren't). While these "high-tech" containers did reduce the amount of watering we needed to do, the time-savings was not huge. In hot weather we're outside watering our regular containers and lawn anyway. And where we live in Connecticut, there is usually plenty of rain for much of the growing season.
2. Sometimes the self-watering container works too well.
We found that over-watering was a problem with our self-watering container, especially early in the season. And over-watering kills plants nearly as quickly as under-watering. Containers that come with bonnets that snap over the opening may help with this problem, but the plastic covers are not nearly as attractive as mulch.
3. The self-watering containers we tried were not large enough for large vegetable plants.
Midway through the season, the plants were root bound (the roots have no more room to grow and become tangled) and showing signs of stress, including wilt. Most species of tomatoes, eggplants, and zucchini need at the very least a 12-inch deep planter. The biggest self-watering container we could find was deep enough to hold only six or seven inches of potting mix (another reason you may want to considering making your own self-watering container). Staking large plants in a such a shallow container is also a tricky proposition.
4. In the plant world, fast growth is often an invitation to disease and insect infestation.
Zucchini grown in a self-watering container started off like gangbusters but did succumb early to borers and wilt. Fortunately, it was not before we picked seven or eight fruits. Photo: Joe Provey, Home & Garden Editorial Services
Container-grown plants do grow quickly if you use the prescribed amounts of fertilizer. While we haven't used the containers long enough to say this promotes problems, it is a concern. Our zucchini did seem to succumb to wilt and borers earlier than it usually does.
5. Self-watering containers are not very pretty.
While they're fine for the outskirts of the yard, we like to place our containers on the patio and deck where we can see enjoy them -- and protect them from critters. You can hide the plastic by building or buying a decorative enclosure, but we feel that would be an unnecessary expense. (Editor's note: We did a little digging -- pun intended -- and found some attractive self-watering planters at Plow & Hearth.)
6. Self-watering containers -- especially in the larger sizes -- are heavy.
Of course, this is true of any large container, but adding the weight of several gallons of water makes even a medium-size container tough to move without a hand truck or casters. This may not sound like a big deal if you're under 30, but if you're pushing 60, it is!
7. Self-watering containers are expensive.
$30 to $60 per planter is pretty pricey for a plastic container. Sure you'd pay as much or more for a terracotta or wood planter -- but then you'd have a really nice-looking terracotta or wood planter that will give pleasure for many years. If you want to try a self-watering container for yourself, consider making your own. There are detailed plans online for self-watering containers
that are far bigger than anything you can buy pre-made.
Have you used self-watering containers? Tell us about your experience in the comments below!