When is the winter period for plants kept in a country with no winter (or a constant room temperature)?

Question

Reading up on how to care for a Mammillaria Elongata Cactus I see it mentions such things as

• suspending watering in winter for best care (and to encourage better flowering)
• the preferred time to re-pot is in the warm season
• fertilizer can be used in the growing season, but suspend feeding in the winter.

When are such periods in a country where there is no winter, and very little or no change in temperature, such as tropical countries (or indoors where the temperature may be constant)?

Is one supposed to follow what would be the seasons in the country where the plant is from, construct ones own winter, by choosing a time to just water less each year and sticking to it, or can you safely treat the plant the same throughout the year?

Answer 1

It depends on which plant you are talking. You should check on gardening book about characteristic of the plant (maybe also on related plants), and you should see what it the trigger on such plants.

Some needs cold period (various limit temperatures and lengths), some requires less sun, some just some rest (after fruiting), some dry period, etc.

For bulbous plants, just take bulbs and put in fridge for one week, and then plant them again.

I would research (or ask here) for specific plant, and see what you can do. In general, I would first try putting the plants in a cold place without watering for 2 weeks (with no direct sun). This should trigger some stress and so they will so hopefully a restart. This should be short enough not to kill the plants.

For orchards an vineyards, some hormones could trigger the winter break (again: it depends on species), but this is done only professionally, where there are already resources and machines to do it, and with expensive plants (so with a pay-back).

Answer 2

If you live in the tropics, it does not make sense to water your plants less during winter time. The reason to do this in temperate climate, is because of less light (both length and intensity), and for outdoor plants also temperature. The plants will enter a period of dormancy. But also indoor plants, such as cacti use less water in winter because of the light reduction. In the tropics you'll have more or less the same light length, and intensity, so the plant would continue with growing (hence the name tropics).

Some plants, however, need a cold period, for instance seeds of many trees need to have a cold period before they germinate, or apples need a cold period before they will bloom and produce fruits. This is hard to accomplish in the tropics.

Answer 3

There's a vast difference between growing something as a houseplant, and growing outdoors in tropical regions. The instructions you quote are clearly aimed at houseplants, which, unless they're indoors in the tropics, will respond to changing light levels from outside, and cooler temperatures at night indoors during winter.

Tropical countries don't really have seasons as such, what they have is a dry season (what passes for winter) and a wet season, or, in some areas, there may be rainfall every day to some degree (rainforest). In those areas which have a dry season, this may go on longer than the wet season, and plants may suffer to a degree because of the dryness, but recover again once the rains arrive.

You don't say what part of the world you are in, so it's difficult to answer the last part of your question with any certainty; you seem to be implying you're in a tropical region, but it's not clear whether you mean rain tropics or dry/wet tropics. Mammillaria elongata is endemic to Mexico, where usually, January is the coldest month, although even that isn't very cold. Regardless, your own plant will respond to indoor conditions rather than those which prevail where it would naturally be growing outdoors.