As uncomfortable as it may be for your grass-types, it’s best to bring them inside for the winter. If you have a larger grass-type such as a venusaur, make sure you have enough room in your home, or consider building a greenhouse for it. Either way, it’s essential for their health that they remain in a temperature-controlled environment. Grass-types, especially those that are purely plants (the bellsprout line, the oddish line, and so forth), can’t thrive in temperatures below 50 degrees Fahrenheit for more than a day. In some cases, it can even be dangerous for them, as they risk wilting the colder it gets. If your pokémon must go out, such as for a battle or to play, remember to limit their time in the cold. Always keep their poké balls at hand, and it wouldn’t hurt to give them warm water after they’re done.

Once inside, light is essential. Give them access to a sunny window during the day, and supplement this with a couple of hours under a sunlamp at night. (A sunlamp may be an excellent investment for you and your pokémon, on that note.) This not only keeps a pokémon’s mood up, but it also ensures the plant parts of them are photosynthesizing as they should be.

Additionally, make sure your pokémon are well-hydrated. Central heating units tend to dry out the air in a home, which in turn can lead to stress or browning from a grass-type. Consider adding a humidifier to rooms where your grass-type will be spending the most time, and always make sure their water dishes are topped off. For pokémon that don’t often drink or otherwise can’t (namely cacnea), remember to spritz a little water on them every other week, but check often for any signs that they’re dehydrated (such as softening needles or bruising skin).

For pokémon in a greenhouse, remember that all pokémon need love and attention to survive. In other words, don’t forget to check on your grass-types daily. Spend time grooming them and giving them plenty of water, and reassure them that you’ll be back the next day.

Finally, keep in mind that all of this concerns pokémon that aren’t coniferous or weather-resistant in nature. Snover and abomasnow actually thrive in colder temperatures, so if anything, now is the time you should be letting them stay out longer. On the other hand, certain pokémon, such as Alolan exeggutor, can’t be kept anywhere and should really be stored in the storage system or at least within their balls any time you don’t need them to battle (or eat, drink, and relieve themselves).

As for your question about leafeon, this is a possible reason why, yes. The other reason why your leafeon’s ears might be growing a little golden around the edges is simply due to age. If her ears don’t return to a vibrant green after spring arrives, you’ll know for certain it’s age. Of course, it’s still not something to worry about; leafeon can be quite healthy, even after their ears turn.