Pets, plots and what actually compounds
A garden grows on its own, but the rate is what matters. A pet that speeds up growth or improves what a harvest returns pays out on every crop that follows, while a single rare plant pays once. That is why the highest prices in Grow a Garden item listings sit on pets rather than on produce.
The same logic applies to plot upgrades and shop rotations, which are funded with currency rather than with trades. Spending there compounds in the same way a pet does. Sizing a Grow a Garden currency order against a specific upgrade keeps it from turning into an open-ended purchase.
The purchases that do not compound are the event crops, which are bought for what they are rather than for what they produce. The escrow behind either kind is described in the Eloboost24 buying guide.