Gadenin日本語Get the appWhy the crown must never get wet
A cyclamen grows from a flattened round tuber that sits at or just above the compost surface. Every leaf stalk and every flower stem rises from a tight cluster of growing points on the top of that tuber, and those points are packed close enough that water poured into the middle of the plant does not drain away. It sits there, in still air, among soft young stems, at a temperature the fungus likes.
The result is crown rot: the base of the leaf stalks goes water soaked and translucent, then brown and soft, and the leaves above collapse. Pull one gently and it comes away with a wet slimy base and a foul smell. Once several stalks have gone this way the tuber itself is usually infected and the plant will not recover, which is why the entire watering method is built around one rule rather than a schedule.
That rule is simple. Never pour water onto the top of the plant, never mist it, and never let it stand for hours in water either. Everything below follows from that.
If you have already watered from above and there is standing water in the crown, do not leave it. Tip the pot at an angle so the water runs out, blot the center with the corner of a paper towel, and put the plant somewhere with moving air for a few hours.
The bottom watering method, step by step
Bottom watering wets the compost from the base upwards and leaves the crown completely dry. It takes a few minutes longer than watering from a can, and it is the difference between a plant that flowers for five months and one that collapses in six weeks. The plastic nursery pot inside the decorative cover is what you water; the cover itself is only a container and should be emptied every time.
- Lift the inner pot out of its cover Almost every cyclamen is sold as a plastic pot with drainage holes sitting inside a foil wrap or a ceramic cover. Take the inner pot out. If the plant was potted directly into a container with no drainage hole, repot it into one with holes before you do anything else, because bottom watering cannot work otherwise.
- Stand it in an inch of water Put the pot in a saucer, bowl or sink holding about one inch (2.5 cm) of room temperature water. Cold water straight from the tap chills the roots of a plant already living in a cold room, so let it stand a while first if it comes out icy.
- Let it drink for fifteen to twenty minutes Capillary action pulls water up through the compost. You can see when it is done: the surface of the compost darkens and looks damp, and the pot becomes noticeably heavier when you lift it. A very dry pot may need longer, up to half an hour, because dry peat based compost repels water at first.
- Take it out and drain it properly Lift the pot clear and let it drip for a few minutes before it goes back into its cover. A cyclamen left standing in water indefinitely drowns just as surely as one watered into the crown; the roots need air between waterings.
- Wait until the pot is light again Do not top it up on a schedule. Lift the pot each time you pass. Water again only when it feels light and the compost an inch (2.5 cm) down is dry to the touch. Learning the weight of a wet pot and a dry pot of that size is the whole skill.
How often, and how the season changes it
There is no fixed interval, because the plant uses water at wildly different rates across its year, and a cool room slows everything down. The figures below are a starting point for a pot around five inches (13 cm) across in a room at 50 to 60F (10 to 16C). Adjust by feel and weight, not by the calendar.
Two things change the interval more than anything else. The first is temperature: a plant in a warm room dries out twice as fast and also declines twice as fast, so if you find yourself watering every other day in midwinter the answer is a cooler position rather than more water. The second is the number of leaves, which is why a full grown plant in peak flower needs far more water than the same plant three months earlier.
| Stage of the year | Typical interval | What you are aiming for |
|---|---|---|
| Restarting in late summer, few leaves | Every 10 to 14 days, lightly | Just damp; too much now rots a tuber with no leaves to use it |
| Autumn, leaves building fast | Every 5 to 7 days | Evenly damp, never soggy, never bone dry |
| Winter, full flower | Every 4 to 7 days | Damp through; this is the period of highest demand |
| Spring, leaves yellowing | Stretch to every 2 weeks, then stop | Gradual drying, following the plant down into rest |
| Summer rest, no leaves | None at all | Bone dry compost in a shaded airy place |
Limp leaves: thirst, rot, heat or dormancy
A cyclamen that has flopped is the most common thing people ask about, and watering it is the right answer only about a quarter of the time. Check the pot before you do anything. If the pot is light and the compost is dry, it is thirst, and a twenty minute soak from below brings it back within a few hours, usually completely. If the pot is heavy and the compost is wet, more water will kill it.
If the pot is heavy and wet and the stalk bases are soft, brown and smell sour, that is crown or tuber rot and the plant is in serious trouble. Stop watering entirely, remove every affected stalk with a twist at the base, and move it somewhere cool with moving air. If the tuber is still firm when pressed the plant can sometimes rebuild; if it gives under a thumb it is finished.
If the pot is neither dry nor waterlogged but the plant sits beside a radiator or in a room that has warmed up, it is heat collapse. Move it to a cooler spot and it firms up overnight without any watering. And if the leaves are yellowing evenly from the outside inwards in spring rather than collapsing green, the plant is not ill at all, it is going dormant on schedule and wants less water, not more.
Water quality does not matter much to cyclamen, but water temperature does. Icy water on a cold day checks the roots and can cause a day or two of wilting that looks like disease. Use water that has stood in the room.