Q: I planted some zinnia seeds in March in a container in my garden. They are only about three to five inches high. Will they ever grow and bloom? Are there ways I can help them? I used a good organic potting soil. The wildflower seed mixture I planted in April also is coming up slowly. Will they bloom this year?
A: This is a case of planting a warm-season annual before it is ready to grow. In March, the soil temperatures are still in the 40s and 50s, way too cold for a zinnia (or a sunflower, squash, bean, etc.) One common result is that seeds will rot, so you’re lucky to have them germinate. Warming soil temperatures should bring them along now, but as insurance, I would sow fresh seed now, and they will develop well in the coming month as the heat arrives. Keep the bed weeded.