The indoor gardening world is undergoing a revolution that no one seems to want to talk about. This revolution is not a step forward, but instead, a huge step backward. More and more plants are now sold in ceramic pots and other containers that have no drainage hole and that leads to a problem. How to you adequately water them?
Remember that plants are traditionally grown in pots with drainage holes. The very earliest gardeners in China and Ancient Rome quickly learned to put drainage holes in their pots and the tradition continues to this day. Terra cotta pots typically have one hole, other pots often have several. When you water, you wait until the soil has reached a certain degree of dryness (slightly dry for most plants, very dry for succulents, especially in winter), then you use a watering can to pour water onto the soil, enough to thoroughly moisten the entire root ball. Just keep on slowly pouring until water starts to drip out of the drainage hole. If you pour a bit too much water into the pot, the excess drains into the saucer below where you can throw it out.
The alternate method – and it is just as efficient – is to pour water into the saucer and let the plant drink its fill, coming back after 15 minutes or so to remove any excess water. (If the saucer is dry at this point, that could mean the plant didn’t get enough water the first time, so you have to fill the saucer a second time, then come back and drain it later.)
The advantage of both methods is that you can clearly see when the plant has received enough water. That way, even though the plant’s watering needs change throughout the year (it will need more water when it is actively growing or when the air is very dry and less when it is dormant or semi-dormant or the air is very humid), you can tell when it gets just what it needs.
In both cases, the result is a well-watered, happy plant that is easy to grow and both death by drought and root rot are rare occurrences.
Watering When There Is No Drainage Hole
If your plant is growing in pot with no drainage hole, though, you have a problem. How do you water it?
Logically you’d still wait until the soil is dry to the touch, but how much water do you add? Your goal is to moisten the mix from top to bottom, but only barely. If you don’t water enough, the plant will remain in a constant state of water stress and will either wilt and die quickly or slowly deteriorate. If you water too much, its roots will soak in water for long periods, leading to asphyxia and rot followed by the death of the plant.
It’s best not to use a watering can to water plants growing in such a pot: it tends to release too much water too quickly, thus leaving the plant soaking in excess moisture. Instead, use a spoon or an eyedropper. Add the equivalent of a spoonful or two of water and check back a few hours later. If the soil still feels dry to the touch, try a bit more water. If it still feels dry, try again. It can be very difficult to calculate just the right amount.
If the soil is moist when you check a few hours later, that doesn’t always mean all is well. There could be too much water! To make sure, tip the plant upside down over a basin or sink and hold it for a few minutes to let any excess water drain out. This is very time consuming and can be very messy (often, a lot of the soil drops out), but at least you’ll be able to keep your plant alive!
The Best Advice
Most plants grown in containers without drainage holes don’t live very long. A few months in the case of foliage plants, possibly a year or so for succulents (they do everything slowly, even dying!). Inevitably they start to rot and die (it’s almost always overwatering that finally kills them). In fact, many are already rotting in the garden center when you buy them (even professional horticulturists have a hard time keeping these babies going!).
If you buy a plant in a pot with no drainage hole and want to keep it alive and well for a long time, not just a few months, don’t delay: repot it into a pot that does offer good drainage. It’s simply the best and easiest advice anyone can give you about those poor badly grown plants!
Drill, baby, drill!
If you want to keep the plant in its original pot, though, there is another solution: drill a hole in the bottom of the pot!
Put on safety goggles and work gloves and insert a drill bit designed for ceramic, tile or glass into your drill. Now turn the pot on its side and start to drill. (If you have a bench vise, use it to hold the pot; if not, do your best to hold it with one hand and drill with the other.) Once there is a hole in the base of the pot, you can put it on a saucer and water the plant normally. Whew! Life is suddenly easier again!
The So-Called Drainage Layer
Some salespeople tell clients there is no problem with a lack of a drainage hole because there is a drainage layer in the bottom of the pot and that any excess water will flow there.
Actually, there probably isn’t. I’ve taken more than a few plants out of pots with no drainage hole and have yet to find one that didn’t contain the same potting mix from top to bottom. In other words, no, there was never any “drainage layer”.
Even if there was a drainage layer, that changes nothing. The drainage layer is an old-fashioned concept that simply doesn’t work. Even if there is a layer of gravel, pot shards or clay pebbles in the bottom of a pot, if it fills with water, the moisture will still move up into the soil above, leaving the plant roots constantly soaking in water and therefore starving for oxygen. This is called capillary action: water will always defy gravity and move upward, leading to roots remaining sopping wet.
The Drainage Hole You Didn’t See
Before you drill though, take a better look at the plant. Some plants (especially orchids) that appear to be growing in a pot with no drainage hole are actually double-potted. There is a plastic insert, or grow pot, with drainage holes inside the decorative container. In other words, the outer container is actually a cache-pot. That changes everything… as long as you know what to do.
When a plant is double-potted, water as usual, with a watering can. Pour on water practically to your heart’s content (yes, even for succulents): the goal is to moisten the entire root ball. Then, 15 to 20 minutes later (use a timer of some sort, you don’t want to forget!), come back, remove the grow pot from the outer cache-pot, let it drain, then dump any water remaining in the cache-pot into a bucket or sink.
Sometimes the grow pot is transparent, allowing you to actually see if you’ve watered well. How brilliant is that? The growing mix should be an even dark brown. If it is dark brown in one part and pale brown elsewhere, you didn’t water enough. Start over!
Before You Buy
Always take a thorough sniff of the soil of a plant grown in a pot with no drainage hole before you buy. The roots of many of these plants are already starting to rot when you purchase them… and root rot eventually leads to stem rot and plant death. If the soil smells like a rotting potato, don’t buy the plant.
I find this situation so terribly sad. It’s simply bad horticulture to to grow plants in a container with no drainage hole… and to sell plants that way is outright scandalous!