A pile of logs stacked under a bush or dumped on your driveway is not going to dry out much. In fact, it will tend to get more and more damp. Placing a tarpaulin over the pile will often make things worse and lead to damp, rot and fungus because moisture is trapped under the tarp, and soaked up by the logs.
Leaving a pile of freshly cut logs in your garden for a wee while, until you can deal with them, is ok. "Green" or fresh cut logs have a water content of up to 60%, so they are not going to get much more wet over a couple of weeks. However, you want to get them drying out as quickly as possible.
In order to burn cleanly logs should have around 20% to 25%, moisture content at most. In order to dry them to this level, they need to be up, off the ground, protected from rain and have good airflow around them.
If you've gone to the trouble of sourcing dry logs from a reputable wood fuel supplier you should look after them and keep them dry. For the cost of a decent load of dry logs, you can buy one of our log stores, which will keep your log supply dry over many years.
Why should I make sure I burn dry logs?