it depends on when you plant it
it depends on the seed, but i think most take about a day.
if i can remember correctly, it takes a few weeks, you plant the seeds(not covering them) and wait. so not very long i guess.
you have to wait as you grow
Wait
you put the one melon slice on the crafting table where it give you melon seeds and you take the melon seed put it in a grass block that has been hoed then just wait for it to grow. ps you need water for it to grow
You have to pollinate the plant first (drag pollen dust to it) and then you have to wait for the seeds to grow. When the seed appears in the box on the far left, you just drag the seed to your seed box or seed storage.
as long as it takes
You will need a rake, a seed dibber, trowel, watering can, compost/super compost, spade, secateurs and the seed. Depending on the seed it will need to be used in a certain patch. Then Use rake with it to rid it of weeds Then Use your compost Then Plant your seed Then Water the seed Then wait for it to grow, and keep checking it, it may need occasional watering and ridding of disease, also don't leave them diseased too long, they will die. Then Pick/Use secateurs ( you will need spade in your inventory )
Go to one of the seed carts and buy 3 seeds. Plant them in the Moshling Garden, and wait for them to grow. Then, if you used the right seed combination, a moshling will come.
Moon Orchid seeds can be found at the Moshling Seed Cart on Main Street. Buy a seed, plant it in your Moshing Garden, then wait for it to grow into a Moon Orchid flower.
To plant an avocado seed in water, first clean the seed and insert three toothpicks around its middle. Place the seed in a glass of water with the pointed end facing up. Change the water every few days and wait for roots to grow. Once the roots are about 2-3 inches long, transplant the seed into a pot with soil. Keep the soil moist and place the pot in a sunny spot.
You should typically wait about 2 to 4 weeks before seeding after applying weed killer.