There’s no mistaking the colour and stature of annual Zinnias. Follow this handy How to Grow Zinnias from seeds guide below and grow some colour in your garden this summer.
When I Get My Seedling Home
Keep seedlings under very bright light to prevent legginess. Artificial lights are ideal, but a bright (ideally, south-facing) room will work for the short term. You may have to pot on seedlings more than once before they go out to allow for root growth. This is done by transplanting them into a slightly larger container with enough additional soil to keep the container mostly full. Keep the soil moist by daily watering and allow for free drainage so the plants are never sitting water.
Transplanting
Do not transplant outside until night time temperatures are steadily 10°C (50°F) or warmer. This may mean keeping seedlings indoors for up to a month. The plants should not require any fertilizer until transplant time. Transplant at 30-45cm (12-18") apart.
Growing
Plant Zinnias seeds in average, well-drained garden soil, but dig in a generous amount of well-rotted manure the previous fall. Pinch off growing tips early in the season for bushier growth. Water regularly, keeping leaves as dry as possible. Deadhead regularly. Feed once in early spring, and again once flowering has begun.