Hi Lyn,
I thought they may not make good garden plants as they may have become too woody and adopted peculiar shapes. They may not have got any decent anchoring or feeder roots down before the snow arrived. I hope you are fortunate with them, if not, think about throwing some seeds in a quiet place.
I have attached some notes gleaned from the Royal Horticultural Society website which may help you. None better.
RHS Publications: Hardy lavender bulletin
Cultivation notes
Growing in the soil
Lavender is best planted between April and May. It thrives in poor or moderately fertile, free-draining alkaline soils in full sun.
On heavier soils, like clay and clay loam, lavender tends to be fairly short-lived, becoming woody at the base. To prolong the life of your lavender on heavier soil, add organic matter and gravel to improve the drainage and plant on a mound. If growing as a hedge, plant on a ridge to keep the base of the plants out of wet soil.
Space plants 90cm (3ft) apart, or if growing a hedge, 30cm (1ft) apart or, 45cm (18in) for larger cultivars.
Once established, lavender is fairly drought-tolerant.
Pruning
Pruning Back to top Lavenders should be pruned every year to keep them compact. On established plants use secateurs to remove flower stalks and about 2.5cm (1in) of the current year’s growth, making sure that some green growth remains. At Wisley, pruning is undertaken in late summer after flowering, although spring pruning is sometimes recommended in books. Lavender does not break readily from old wood and neglected specimens are best replaced.
You can easily make more lavender by taking semi-ripe cuttings in late summer.
Sorry about the weather,
Peter
