Garlic won't cleave

[Captain Spod]

For the past two years I have planted garlic (the proper horticultural stuff) on the 21st December and pulled up the very healthy plants the following June. All I get is a big single bulb, they won't cleave or split into cloves. I thought that they would if they experienced < 5 degrees C for a few days but they certainly did that last winter and still no joy.
Ever the optimist I have bought more bulbs this year, what shoul I do differently?

[Clanad]

First, are you planting the whole bulb? Only the outer, single cloves should be planted. Although I'm in the western U.S. I suspect you should be planting the cloves earlier... say September and they should be harvested in late summer... no earlier than August or September. However, having said that, I use September as a rule of thumb since we get our first light frosts in that month and the garlic should be planted when the frost has come and the nights are cold enough so as not to encourage growth.

A fairly even fetilizer application (10-10-10) should be applied thoughout the growing season and if you experience several dry days or weeks be sure to water thoroughly but not overly. they don't like wet deet...

The flat shaped leaves should have browned and almost died away as a cue for harvesting... As any dedicated gardener says "There's always next year!"

[kia cat]

The last time I grew some, I put them in a grow bag stood on it's edge. I didn't bother with the horticultural ones, just some supermarket ones. Split into cloves; using the fat outside ones.Just made holes in the bag and poked them in. Sunny position, planted late summer and picked in following July. Don't overwater. Let the picked bulbs dry out [ hang by stems - or plait up if your feeling French! ] You could try "Growbag Greenhouse Product no. 590950" from homebase, about £15, if you haven't a greenhouse of your own. Hope that helps. Sorry for late reply, only just come across your qu.