You don’t want to pay for new plants twice. Even though warm temperatures continue local gardening experts are warning it is not time to spruce up your landscaping.That’s because it is likely cold weather and plant-killing frosts are not over.Travis Watson, the campus arborist at East Tennessee State University, said it is far from unusual to have frosts up through April and May. Watson says plants native to the region tend to do well with frost, but the plants commonly used as decoration around houses do not.