Is this Tirnani homebrew race balanced?

Question

In ages past, a vast empire of beast folk ruled the lands after driving destructive elementals from it. In time, they grew corrupt and enslaved a race of druidic fae folk to their service, so they could terraform the land as they pleased. These fae rebelled and were slaughtered by their masters. But the Great Goddess Florine took pity upon them and bound their spirits to slumber in the Feywild. Ages later, an elven song called them to rise anew and ever since then, they have been firm protectors of the wild.

They're meant to be good rangers and druids. My main balance concern is forest warden.

• Ability Score Increase: Your Wisdom score increases by 2 and your Dexterity score increases by 1.
• Age. Tirnani become mature at around 75 years of age and can theoretically live forever. Young tirnani are swift and energetic, while ancient ones are careful and sluggish
• Size: Tirnani are usually taller than humans on average. Your size is Medium.
• Speed: Your base walking speed is 30 feet.
• Stench of Corruption. You have advantage on Wisdom (Survival) checks made to track fiends, undead or aberrations. In addition, you have advantage on Intelligence checks to recall information about them.
• Soil Slumber. You don't need to sleep, and magic can't put you to sleep. You can finish a long rest in 6 hours if you spend those hours rooted in soil or loose earth. In addition, resting in this way can replace the need for food and drink.
• Friend of Beasts. Your plant-like body is home to many small animals willing to aid you. You know the mage hand cantrip, and when you cast it with this trait, the hand takes the form of a swarm of tiny beasts such as beetles, ants or mice. The cantrip also doesn't require components when you cast it with this trait.
• Forest Warden. Once per turn, when you hit a creature with an attack, you can cause writhing vines to wrap around it. The creature takes extra damage equal to your proficiency bonus and must succeed on a Strength saving throw, with a DC of 8 + your proficiency bonus + your Wisdom modifier or become restrained until the end of your next turn. You can use this feature a number of times equal to your proficiency bonus and regain all expended uses when you finish a long rest.
• Languages. You can speak, read and write Common and Sylvan.

Answer 1

This is dangerous, test it

ASI, Age, Size, Speed and Languages are all the standard fare that most races have and are unproblematic. You are missing one of the more important parameters, Creature Type. I will assume those are Fey, based on the introductory text, but this should be made explicit. Looking at what is differentiating this:

Friend of Beasts: Mage Hand in and of itself as a free cantrip is fine. Mage hand already has lots of questions on how it works. With it being composed of a swarm of creatures, which could take damage, be attacked etc., be prepared for even more questions at the table you need to work out on the fly. Maybe just say that it looks like a swarm of creatures, or tangle of roots or such?

Soil Slumber: this is a slightly toned down version of Elven Trance (which can do it in 4 hours) and the sleep part of Fey Ancestry. Fine.

Forest Warden: once per turn means this will work also on opportunity attacks, but that may not be so bad, as the most effective way to abuse this is anyways if all gang up on the restrained creature, so being able to restrain two per turn may not make a big difference. Restrained is a pretty tough condition to impose, all of you get advantage to attack them, they have disadvantage on attacks and Dex saves, and they cannot get away.

• This will translate into a lot of extra damage if the whole party beats up on them. For some rough estimates (obviously, this always depends on the specific situation): Advantage can add +4 or +5 to hit, so assuming a damage output of about 10 points per character, for a party of 4 this would deal about 12 to 15 extra damage even at lower levels, increasing the party damage output by 30% or more that round.
• In addition, it will save you some damage. Again, this is situation dependent, but the average damage from attacks for monsters is also around 10 per attack, and many have 2 or even 3 attacks, so via Disadvantage this can also save you 4-12 damage per round, the rough equivalent of a cure wounds or healing potion.
• It is limited in uses and gated by a Save, but you have enough uses to use this in nearly every encounter, and the DC is serious, likely based on your prime ability score.
• This does not cost you an action, not even a bonus action. Compare this to a spell like entangle, which takes your full action and spell for the turn to achieve the effect. Granted, it only holds for a round, but most fights only take about 3 rounds, so I think this is possibly even better than the spell, or at least not much weaker - and you get it multiple times per day.

The number of features is in line with than what we see in the newer published races, which is OK. This seems not overloaded.

I think Forest Warden is pretty dangerous, and may make this a bit to effective. Keep in mind that the character can opt when to use it, so they will likely use it against the Ogre where it matters, and not waste it on a random Goblin (unless it matters). The other stuff is fine and not too much of it, so it might be OK, but you should playtest it.

Answer 2

This race is weaker than a feat.

It's also weaker than the races used in optimization like Bugbear or that stone halfling or anything with flight.

Being able to restrain someone for a round if they fail a save as part of an action puts it on par with the not too optimizable but still with features that actually see use races, like Half-Orc or Wood Elf.

This leaves it above most 5e races that have features that rarely come up in game, but below the ones generally chosen for their utility.

If your aim is to leave it with largely fluff features like most 5e races, that rarely (or never) come up in a typical campaign, then Forest Warden is too good. If your aim is to have it compete with races like Variant Human or Aarocokra, then it is significantly too weak.

If you define balanced as not weaker than the weakest race and not stronger than the strongest race, then it is balanced. It sits slightly above the median line, but only because so many races have such incredibly forgettable mechanics. It is nowhere near the mechanical strength of the stronger races.

As a small design note, you don't want the save for Forest Warden to be Wisdom. That shoehorns the race into playing classes that use wisdom. Have it be Constitution based instead, or have a flat DC (12 + proficiency modifier) that isn't based on an ability.