Several versions of this around - pick yer favorite verses and create your own...
-Wood Burning Rhyme-
Logs to save the coal a turn,
Here's a word to make you wise,
When you hear the woodman's cries.
Never heed his usual tale,
That he has good logs for sale,
But read these lines and really learn,
The proper kind of logs to burn.
Oak logs will warm you well,
If they're old and dry.
Larch logs of pine will smell,
But the sparks will fly.
Beech logs for Christmas time,
Yew logs heat well.
"Scotch" logs it is a crime,
For anyone to sell.
Birch logs will burn too fast,
Chestnut scarce at all.
Hawthorn logs are good to last,
If you cut them in the fall.
Holly logs will burn like wax,
You should burn them green,
Elm logs like smouldering flax,
No flame to be seen.
Pear logs and apple logs,
They will scent your room,
Cherry logs across the dogs*,
Smell like flowers in bloom.
But ash logs, all smooth and grey,
Burn them green or old;
Buy up all that come your way,
They're worth their weight in gold.
*log dogs are name for the metal risers in the fireplace to allow air underneath.
Here is a quicker memory aid from the Scouts (UK)
These hardwoods burn well and slowly,
Ash, beech, hawthorn oak and holly.
Softwoods flare up quick and fine,
Birch, fir, hazel, larch and pine.
Elm and willow you'll regret,
Chestnut green and sycamore wet.