By Larry Hodgson
Question: I bought a small calamondin orange tree with cute orange fruits a few weeks ago, but it’s not doing very well. The leaves are rolling up and starting to drop off. However, I have been following the advice that they gave me at the nursery, that is, to give it a location where it enjoys the sun for a few hours a day and to water it regularly when the soil is dry to the touch, but only a little bit at a time. So, since the soil is always dry, I give it a teaspoon or two of water every day. What do you think is wrong with my plant?
Answer: I think you misunderstood the instructions for watering your calamondin (Citrus mitis, syn. × Citrofortunella mitis).
You should never water any plant “only a little bit at a time.” You always need to water it copiously, enough to thoroughly wet the entire root ball, not only moistening the soil at the top of the pot, but also right through to the bottom. This applies not only to typical houseplants like your calamondin orange that like moderately moist potting soil at all times, but even to succulents adapted to dry soils (cacti, for example). Yes, even a cactus needs a good soaking once it’s fully dry, not just a few spoonfuls!
If you only give tiny amounts of water to a plant at a time, the roots—and especially the lower roots—will dry up and start to die. And when the roots die, the whole plant suffers! That the leaves of your plant are rolling up and falling off shows that its root ball has dried out far too much and that the superficial watering you’re giving it is insufficient. It’s essentially dying of thirst!
The golden rule of watering (which applies to essentially all plants grown in pots) is to wait until the soil is dry to the touch (stick a finger into the soil to check), then water thoroughly, enough to soak the whole root ball. After 10 to 20 minutes, discard any excess water that collects in the saucer.
Unfortunately, leaves rolling up in this fashion show a plant that is seriously dehydrated. It may be too late to save it, but still, I encourage you to try. The following emergency watering technique may be able to revive it:
Helpful Hint: When a potting soil is completely dry, it’s time to give it a good soaking!
As the soil is nearly dust dry, normal watering probably won’t suffice. That’s because, when soil is extremely dry, rather than absorbing water immediately as it should, it initially repels it. So most of the water you pour onto the plant’s soil will likely just flow right through without helping it. It will therefore be necessary to rehydrate the soil particles so they can start to act normally.
To do this, place the pot in a large recipient—a bucket, large bowl, sink, etc.—and fill the tank with water up to the top of the potting mix. You may need to put weights on the pot to hold it in place; otherwise it may start to float! Let the pot soak in water for 20 to 40 minutes to allow the root ball—and any roots still alive—to completely rehydrate. Then, remove the pot from the container and let it drain well.
From then on, water normally, watering (thoroughly) when the soil is dry to the touch again. And you may not need to do so for quite some time, as the plant now has fewer roots than it did before, so it likely won’t need very frequent watering for a while.
But don’t give up hope: as long as there is a little green on a plant, it is usually possible for it to recover.