|February is a month with some warmer days (here in Greece at least) and sometimes it looks like the winter is already over!! But there is still the danger of low temperatures and frost. So, cacti must stay in their sheltered location, protected from rain and snow. Don't be deceived by some buds that start to emerge, especially at some mammillarias. These cacti can stay unwatered until their buds are better formed and bigger. Then they can be watered carefully on sunny and relative warm days. Of course, these cacti need a lot of sun light.
The rest of the cacti also need a lot of sun light and since the days start to get longer, cacti are happy. If you have any cacti inside, you can take them out on days and hours when temperatures are higher and bring them back inside in the evening (thats what I do with my melocacti...)
Another thing that must be done is the ventilation of the protected cactus location. Especially, when the sun shines on warm days, the temperatures inside a small greenhouse or with plastic covered space can climb very high. I always leave one side of my small construction always open, even during the night (when night temperatures fall only at 7-8 C). Visit some weather forecast website and take precautions when there is any forecast for bad weather. I use cardboard pieces that I place around the construction and if temperatures are expected to fall below 0, I cover the whole construction with some old blanket or carpet.
Don't be tempted to water the cacti yet because it would be very bad if the temperatures drop, which is not rare this time of the year. If someone thinks that some plants should be watered (cacti with flowers) it is important to check the weather forecast and water only when the weather forecast is good weather (over 150C). Like the other winter months, notocacti and parodias can be watered carefully on warm and sunny days and only when, according to weather forecast, the good weather is going to last for a week.
This month when most cacti are still "sleeping" someone can start with repotting whenever it is neccessary. This is a good time to repot because cacti will have the opportunity to start their annual growing period in spring in their new pots. Cacti with flower buds or flowers should better left to be repotted after they finish flowering. For repotting, like with watering, I prefer days with good weather. When it is warm and dry, the soil (which usually has some moisture, especially most commercial soil) will have the opportunity to dry out completely within a few days. Of course, after repotting we don't even think about watering the plants!
Some cacti that may flower this time of the year: mammillaria gracilis, mammillaria hahnianna, mammillaria conspicua, mammillaria carmenae, cacti of the genus echinofossulocactus (stenocactus), mammillaria rekoi,