I didn't have any problem while gardening, I have a Seasons EP, it's better to put your plant inside the house using a gardening box/pot, create a room like a greenhouse because when you put your plants outside and the current season is not the same as a plant season, a plant will become dirt, but when you put a plant inside the house a plant status become sheltered, basically it just needs a room with a roof to make a sheltered status, you can use replace the wall with fences, but there are also plants that can be planted in all seasons so just put that plant outside.
Just bring outside your plant when the current season is the same as a plant season, one day before the season changes don't forget to bring back a plant go back to your greenhouse, don't forget to pollinate with bees to make your plant perfect quality, some tips you can buy a sprinkle so you don't need to water the plants every day, but you can't raise your gardening skill, upgrade sprinkle to prevent puddle when inside a greenhouse cause puddle can make sims uncomfortable, when your sims have a high skill on gardening you can fast weeding, bug spraying, and harvesting plant because one harvest = area harvest, one weed = area weed, one bug spraying = area bug spraying, and more, like a super sell (sell nearby harvestable), sell harvestable, so your harvestable will sold automatically (not saved in your sims inventory), don't forget to "study" a fossil to make your sims focus so you can improve your skills quickly while in focus mood.
And don't forget to check a season calendar when you have a Seasons EP.
Q: But how to place a tree inside a greenhouse? it's too big.
A: To create a greenhouse for the tree plants, you just need a room with 2 levels.
Q: How to pollinate a plant with bees?
A: First thing you must buy Bee Box and then Bond with Bees until your friendship between you and bees is raising, so a collect swarm option is unlocked, when the swarm is collected it can be found inside your sims inventory, go walk around your plant and choose the option "pollinate nearby plant", pollinate with bees is like fertilize the nearby plant, so you no need to fertilize a plant again.
Q: How you can fast-moving a plant?
A: Use build mode, so you can put your plant in your household inventory, that does not make your plant back to dirt.