Should You Put Compost in the Planting Hole?

This one is going to get some pushback.

If you've ever dug a nice hole, filled it with compost, then popped your plant in, you were following advice that's been standard for decades. And the science is out...it's a bit backwards.

Amending a single planting hole with compost usually does more harm than good. Roots tend to stay inside the enriched hole rather than spreading into the soil around it, which stunts the plant's long-term growth. Whole garden beds are a different story, amending an entire bed evenly is fine, and often genuinely helpful.

Why compost in the hole seemed like a good idea

Compost is soft, rich, easy for roots to grow through. So the logic seemed obvious, give the plant the best possible start by filling its hole with the good stuff.

Just like most teenagers, roots are lazy. Just enough sense to make it work in their favour, they take the path of least resistance.

Fill a hole with rich compost and leave the surrounding soil untouched, and roots tend to just stay in that comfy pocket instead of pushing out into what's around it. The plant looks fine for a while, then stalls, because its whole root system is still sitting in one small hole instead of spreading through the actual soil.

What the research actually shows

This isn't a fringe opinion. Dr Linda Chalker-Scott, Extension Horticulturist at Washington State University, calls it directly:

"Of all the fictions that abound in popular horticulture, none is as deceptive as this one."

Her research, alongside work from Dr Carl Whitcomb, a root systems specialist formerly of Iowa State University, shows the same pattern over and over. Roots hit the edge of the amended hole, where the soil suddenly changes texture, and instead of pushing through, they circle back into the easier ground behind them. University of Florida research found the same root-circling effect can eventually girdle and strangle the plant at the trunk.

Washington State's own findings go further, water moves quickly through the loose, amended hole but drains slowly into the denser native soil around it, so the hole floods and waterlogs the roots instead of draining, the exact opposite of what anyone amending a hole is trying to achieve.

The actual fix

It depends on what you're planting.

If you're planting into a whole bed, a vegetable garden, a raised bed, several plants going in together, amending the entire bed evenly is genuinely fine, and often the right call. There's no abrupt boundary anywhere inside the bed for roots to get stuck at, so the "cushy pocket" problem never happens.

If you're planting a single tree or shrub into open ground, skip the amendment altogether. Dig the hole two to three times wider than the root ball, but only as deep as the root ball itself, so the plant sits on firm ground rather than settling and sinking. Let it root straight into the native soil around it, no interface, no boundary, nowhere for the roots to act like teenagers and get lazy and stop moving.

The part that actually matters more

Whether you're amending a whole bed or using straight native soil for a single tree, neither one will work if the biology's not actually there. Compost, native soil, doesn't matter, without the fungi and microbes to make that structure actually function, roots still won't get what they need. That's a separate job entirely, and it's exactly what's worth adding the moment you plant.

Your plants aren't struggling because of what you're doing. They're struggling because of what's missing from your soil.

Shop RootWise Balance today and get some balance back in your garden