Brand new to dahlias. Planted a tuber in a pot about four weeks ago. About two weeks ago it sprouted. It has remained the same heat for two weeks. Abut one inch tall. Today I noticed some new growth, not in height, but in a few new sprouts. None look super healthy. The older sprouts are reddish green. The new ones are just red. None are yellow or have a rotted look. But why else wouldn't they be growing?