Growing cactus in sand

[marvinbase]

Have researched trees, and can grow saguaro cactus in growing zones in soil in my biome. However, I can't seem to add a growing zone in sand, even though sand fertility is 10% and cactus requires 5%. Is this just a limitation of vanilla, or am I missing a method to grow cultivated cacti in sand?

[Neosuduno]

the needed growning space is 2*2, so if you are only making a row 1*x then no trees will grow, even cactus.

[Grimelord82]

If they work like standard trees, you can create a zone that is shaped like a comb: a spine + tines. If the tines are every other square, it should work.

[marvinbase]

Sorry, issue isn't that they aren't growing, it's that when I try to drag the grow zone over sand it won't "stick". I have a 1x grow zone along my peremeter wall in soil that and they grow fine as long as another set of plants are not next to them, but when I try to expand the grow zone further into sand ithe zone doesn't get added.

[Khan Boyzitbig of Mercia]

The vanilla growing zone only supports gravel and above because it is for all crops, you cannot grow anything else in sand so sand isn't supported.

[Astasia]

You couldn't grow cactus until 1.0, so growing zones have always been designed to not be placeable on sand. The system just wasn't updated to make sense, so colonists are simply unable to figure out how to plant a cactus in sand.

[marvinbase]

OK, was afraid of that. Just wanted to be sure there wasn't another option in an obscure menu somewhere. Thanks for the answers!