The second one, which is new but even more effective from Skyzhay's blog

The best way to start OSRS GP learning to master Farming skills will be through questing. You can easily reach up to 35 levels of Farming through easy tasks. Check out what tasks will bring you the best rewards and which ones you'll be able complete , and get going for an easy and quick approach to beginning your training.

If questing is not your thing , or you simply aren't able to complete your missions due to some reason, then you might want to focus on checking Bird Houses located on Fossil Island. For this, you will have to complete a few tasks, such as Bone Voyage, that requires 100 Kudos within the Varrock Museum.

It's not that difficult to accomplish, however, it will require a little amount of research to know how to do it. If you manage to make it there then you'll be able to gather a number of seeds from the previously discussed Bird Houses. It's by far one of the most efficient ways to get some materials to start farming.

The second one, which is new but even more effective, is Winterodt. This mini-game is easy to play and only requires 50 Firemaking participants and can provide you with tons of rewards after completion. You can find seeds in the game as well to use in your farming leveling. Because this minigame can be played over and over again and you are able to farm it to obtain supplies. If you've got a good combat level, you might also earn seeds from bossing and killing creatures like Demonic Gorillas Kalphite Queen Callisto, Venenatis, Giant Mole and Zulrah.

If you've got the seeds that cheap OSRS GP you need to cultivate Farmers, you'll require some compost. One of the easiest  ways to make an abundance of it is through charter vessels in which you can buy pineapples. But you can also use harvested watermelons as they can be easily acquired. If you have the fruit of your choice, it is best to be able to put it into a composter where you mix it and Volcanic Ash.