The most essential resource you need to start a garden is Contribution Points because fences are rented from NPCs rather than purchased.

The required number varies by fence type, but the highest-grade Strong Fence requires 10 Contribution Points. You will get those 10 Contribution Points back when you return the fence.

How to Easily Find Fence Rental NPCs
Press the magnifying glass icon at the top right-side of the screen and search for "Fence" to find the nearest NPC who rents the fence you want and get exact directions to their location

Fences you rent can only be placed outside of safe zones.

To install one, right-click the fence icon in your inventory to enter Place Mode, then move your mouse to position the fence wherever you like.

Avoid obstacles such as rocks and trees when placing the fence. If possible, set it up near an area you visit often so you can tend to your crops easily.

▲ You can only install the fence where the box appears blue in Place Mode.

Once the fence is in place, step inside it and press R to interact with it and begin managing your garden.

With your garden set up, it's time to plant some seeds.

You can obtain seeds by gathering them from bushes and similar sources, or simply buy them from NPCs. In addition to seeds, you can plant seed sweet potatoes, seed potatoes, hypha, and haystacks in your garden.

▲ Planting seeds works much like placing furniture. The seeds you can plant appear on the right side of the screen, so just click one and set it down wherever you like. You can also press the number key assigned to each seed to place it.

One thing to watch out for when planting is the maximum number of crops your garden can hold. Check each seed's tooltip to see how many grid slots it takes up and plan your planting accordingly.

▲ Each crop takes up a different number of grid slots in your garden.

Once all your seeds are planted, the crops will start at 0% growth and grow steadily as time passes. 

Now that your seeds are planted, it's time to take care of them. Crops are sensitive. They're affected by humidity and temperature, and can suffer from pests and bird attacks. You'll also need to prune them and keep an eye on their moisture at all times.

Pest infestations and overgrowth that requires pruning can occur randomly while your crops are growing. When either problem occurs, the crop’s growth speed drops sharply, so it is best to address it quickly. 

Pruning crops and killing pests earn you Farming EXP. You also have a chance to obtain loot, including valuable items such as a Sharp Black Crystal Shard.

▲ Any issue in your fence is indicated on the World Map in red.

▲ If the yellow gauge turns red, the crop has pests or tangled branches. Head over and interact (R) with it to prune or kill the pests (consumes 1 Energy).

It also helps to know about the devices you can place in your garden to protect your crops.

First, consider placing a scarecrow, which protects your crops from bird attacks. Bird attacks reduce crop health and slow growth, so using a scarecrow can noticeably improve your harvest. 

To craft a scarecrow, purchase a house and convert it into a Carpentry Workshop. 

▲ Without a scarecrow, your crops have no protection against bird attacks.

Now let's look at what you can do yourself to tend to your crops. When a crop's moisture reaches 0%, the yield you get from harvesting and plant breeding is halved. If a crop is running low on moisture, bring Distilled Water (or Purified Water) in your inventory, then use (RMB) it in your garden to replenish the crop's moisture.

To get Distilled Water, buy an Empty Bottle from a material vendor and use it at a river to obtain a Bottle of River Water, then heat it via Processing (L).
To obtain Distilled Water, buy an Empty Bottle from a material vendor and use it at a river to collect a Bottle of River Water. Then, open the Processing (L) UI and select Heating.

Finally, if all of this feels like too much hassle, you can send workers to do the job for you or simply leave your crops be.

Workers won't help with moisture or bird attacks, but they will handle pruning and pest control for you, and they tend to an entire garden at once, which is very convenient.

Leaving your crops unattended means letting birds and insects have their way. Crops left alone take much longer to reach 100% growth and become harvestable, but the upside is that you are free to do other things in the meantime.

So it all comes down to your playstyle. Tend your crops yourself for a bigger yield and more Farming EXP, or go hands-off and take it easy, spending that time with monsters or doing whatever else you please. 

▲ Assigning a worker to manage your garden is another effective option.

Whichever method you choose, a crop is ready to harvest once it reaches 100% growth.

When a crop reaches 100% growth, you can either Harvest it to gather its produce or use Plant Breeding for a chance to obtain higher-grade seeds.

Successful Plant Breeding grants several seeds one grade higher than the seed you originally planted.

▲ Left: Harvest. Right: Plant Breeding (Plant Breeding has a set probability to succeed).

If a fence goes unused for 28 days or more after installation, it is automatically removed. Note that any crops left unharvested in the garden are lost when this happens. Removed fences are sent to the storage of the region where they were installed.

If no crops are planted, you can remove a fence yourself to pack it up. You're also free to carry a fence with you and set up your crops wherever you like.

Mysterious Seeds can be obtained at a low rate through Plant Breeding.

Combine a Mysterious Seed with a crop seed by using Shaking to create a Mysterious Seed for that crop. Plant it in your garden to obtain a large amount of produce at harvest.

A Mysterious crop seed takes up five times the garden space of its regular version, but it yields more, so the end result is much the same as planting several regular crops.

Taking up more space also means far less time spent managing your garden.

On top of that, Plant Breeding a Mysterious Seed guarantees 30-40 yields, making it especially useful when you want to stock up on fruit for Alchemy.

▲ Mysterious Seed, obtainable at a low rate through Plant Breeding. Not only does it make harvesting and breeding more convenient, it also guarantees fruits.

Magical seeds are rare seeds that only characters at Farming Artisan 1 or above can obtain.

Plant Breeding with a character at Farming Artisan 1 or above can yield a "Magical Seed." Much like the Mysterious Seed, it takes up five times the space of the regular version, and in return, it yields roughly as much as harvesting the regular crop five times over.

At first glance, Mysterious Seeds and Magical Seeds may seem much the same.

Mysterious Seeds, however, can only be obtained at a low rate through Plant Breeding, which makes it hard to sustain a garden on them alone. On the other hand, at least one Magical Seed can be obtained through breeding, so you can keep every garden filled with magical crops.

Magical Seeds also sell for a fairly high price, so selling excess seeds to vendors can provide a useful source of additional Silver.

Because growth time and shop price vary by crop, choose whichever crop suits you best. If you can tend your garden often, try fast-growing crops even if they sell for less; if you cannot, choose pricier crops with longer growth times.

Additionally, breeding a Mysterious Seed always yields fruits for Alchemy, while breeding a Magical Seed only yields them by chance. So, if you have a character at Farming Artisan 1 or above and want convenient harvesting and breeding, focus on Magical Seeds. If your Farming level is low, or you're tending a garden to stock up on fruits for Alchemy, focus on Mysterious Seeds.

Once you reach Farming Master 1, you gain access to a fence that's far easier to manage.

Speak to the Old Moon Manager in any town to rent an Old Moon Fence with Contribution Points. This fence holds up to 10 crops, just like the Strong Fence, but it's about half the size, making it easier to place and tend.

Like the Strong Fence, the Old Moon Fence costs 10 Contribution Points to rent, and it shares the rental limit with other fences. So if you're already renting 10 Strong Fences, you'll need to return one before you can rent an Old Moon Fence.

▲ Speak to the Old Moon Manager in any town and invest 10 Contribution Points to rent an Old Moon Fence.

You have a chance to obtain Mole's Feed when harvesting or breeding plants.

When you obtain Mole's Feed, a mole will burrow up from the ground near your garden. Defeat it to get Blush Leaves, Black Stones, Spirit Pouches of Ferocious Beast, and more in large quantities.

Planting Magical Seeds or Mysterious Seeds also gives you a higher chance of obtaining Mole's Feed.

Note that while a mole is already out, obtaining more Mole's Feed will not make another appear. A mole also won't appear if another monster has been summoned by your party or platoon.

Pit-A-Pat Mole appears!

Several types of moles can appear when you obtain Mole's Feed. Defeat one of them, the Giant Mole, and there's a small chance the Pit-A-Pat Mole, a mole with a special appearance, will show up.

 
▲ Appearance of the Pit-A-Pat Mole.

The Pit-A-Pat Mole cannot be defeated. You have to chase it away instead. Once you do, you'll receive even more Blush Leaves, as well as an item called Pit-A-Pat Petal.

Collect 10 Pit-A-Pat Petals, then accept and complete the Trace of Pit-A-Pat Mole quest from Jemkas Wyrmsbane at the Northern Guard Camp to obtain the Pit-A-Pat Mole pet.

※ The Pit-A-Pat Mole pet has an appearance of a mole and can only be combined with another Pit-A-Pat Mole. It cannot be combined with a Gosphy. 

※ The Pit-A-Pat Mole pet comes with the Finds Resources special skill and the Life EXP Boost talent.