I'm the tenant and the landlords want to start a garden in the backyard of the property I rent. Is this lawful. I live in St. Louis. Thank you for your help in advance. Dayle

Yes its lawful. If the terms of the lease say something about it.

Does the landlord provide the landscaping work or is that your problem to do? There is a lot of "well it depends" here.

But generally... if there is nothing in the lease to that effect. They typically wouldn't.

If you rent the entire property (and they do not live there), no, they can't just show up and plant a garden UNLESS it's provided for in your lease.

Of course, they can if you agree.

Most tenants don't pay any part of the water bill, but that would be a factor if you do.
There's a lot of other questions for this question:
How big is the back yard and how much room will the garden take? Do you have lawn furniture that would have to go away?
Was there an 'expectation' of enjoyment of the yard that will be gone, such as you might have with a tiny city postage stamp back yard? Is it a single family or multi-family, with other tenants and or the landlord living in another part of the building?
Or are you in the burbs, with a huge yard of which this will be a small part?

(Aside from legalities, have they offered to share produce with you, or work for produce, even just watering early in the a.m. before the sun bakes the soil and burns the leaves?)

In general unless it's specifically stated you rent the entire premises, and that includes the yard. This would change the renter's quiet enjoyment of his/her property.

I say the rest does not matter - unless it's a specific clause the landlord cannot decide to use the property for gardening (or any other purpose).

Yes, please provide more info, is this a home you share with the landlord ?
Is it a separate house you have ?