i am planning to start a cut flower business I wounder what the early to sow zinnia seed before the 4-7week before the last frost.
What country are you in?
How much heat /protection from frost , do you have?
If you have a heated greenhouse, with a minimum of 10C you can start them anytime from now in the Northern hemisphere, to grow on into large plants to plant out after the last frost.
thry also don't like root disturbance so best sown into individual cells/pots
Sarah Raven knows her stuff. You can germinate all sorts of seeds but if you haven't the space in a really warm greenhouse they struggle or die. Those nifty little plug plants can be just the same and should be chosen with care.
SR suggests sowing in March-May and her advice is usually sound. Zinnias seem to be fussier than most seeds but they are so lovery it's a shame not to give then a bit more TLC. It will be my first try with these too.
Your on aym 280!
I grow Zinnias every year and sometimes they can be fickle! Last year for some reason I lost all my 1st showings. Thy really do need the right environment. But
Oops what happened......It posted it self!!!!!
What I was saying is that they are well worth the effort and last all summer long.
Definitely need heat to germinate well.
Also I sow in individual pots as they are best not disturbed ( although I have been quite successful in doing so in the past). Last year because of the first sowing failure I direct sowed some, they were all fine but had to be on slug patrol watch and I used a cut down plastic bottle to protect the young seedlings.