Each spring, I can wait to start out zinnia seeds. But when I leap the gun and begin too early, my seedlings can succumb to a late frost. If I begin them too late, their means to flower is proscribed by summer time’s warmth. So over time, I’ve discovered to start out them at simply the best second.
Zinnias are vital vegetation within the veggie backyard. Growers throughout can begin these vegetation from seed and convey within the butterflies, bees, and wasps that pollinate fruiting vegetation. They’re a boon to flower gardeners, who look to zinnias for his or her many kinds and colours.
If you wish to develop zinnias for pollinators, stick with single or double-petaled varieties. Exterior these limits, there’s a lot to get pleasure from. Dahlia and cactus sorts supply curiosity to gardens, rising tall and powerful via the season. They seed out as the primary frost rolls in, and re-emerge in spring in the identical spot in most areas.
The Backside Line
Use your final frost date and your season size to information your timing. Basically, gardeners in all zones ought to begin zinnia seeds straight within the backyard one to 2 weeks earlier than their final frost. It takes roughly two months for zinnias to achieve their blooming stage.
Most zinnia varieties emerge inside a number of days and as much as just a little over every week after planting. After they bloom, deadhead them for one more flush of flowers. They’ll proceed to bloom into fall in areas the place the chilly comes slowly. In colder areas, frost tends to kill them off.
A Regional Information
Now that we’ve coated the fundamental guidelines for when to start out zinnia seeds, let’s talk about a number of the regional nuances. Be aware that the final frost dates we offer listed here are approximate. You must at all times seek for your common final frost date based mostly in your zip code. Even that date is approximate, given at present’s climate extremes.
Yet one more factor! In zone 1, the season isn’t lengthy sufficient to straight sow your seeds. You possibly can begin them indoors below a develop gentle. Use a warmth mat and sow them in paper pots to make sure the vegetation don’t succumb to transplant shock, and get them within the floor outdoor ASAP to benefit from the blooms earlier than it will get chilly once more.
Zones 2-4
In zone 2, the projected final frost is in mid to late Might, from the fifteenth to the twenty second. Subsequently, plant your zinnia seeds early within the month, ideally within the first week. Zone 3 isn’t far behind with final frosts occurring between the first and fifteenth. Zone 4 has frosts occurring from April twenty fourth to Might 1st.
In zones 3 and 4, you don’t should get your zinnias within the floor instantly. Each have roughly 4 months of rising season, so so long as you get them within the floor inside every week or two after your final frost, you’ll have loads of blooms earlier than the primary frost rolls via. However don’t wait too lengthy, otherwise you’ll miss out!
Zones 5-8
In zones 5, 6, and seven, the final winter frost happens between April seventh and March twenty second. Simply as zones 3 and 4 have effectively over the 2 months wanted to develop a zinnia from seed to flower. Zones 5 and 6 have 5 months, and zone 7 has six. Begin zinnias in these zones in the beginning of April, or within the final week of March.
Right here in zone 8, I’m about to start out zinnia seeds. It’s a dicey endeavor, although, as our final frost – although projected to happen in mid to late March – can generally happen within the first or second week of April. Here’s a living proof about final frost dates. They’re very localized.
So different gardeners in zone 8 may begin their zinnia seeds now, however they’ll want to offer some cowl in case of a snap freeze.
Zones 9-12
In case you reside in zones 9, 10, 11, or 12, you can begin your zinnias now, and you might have already began them. In these zones, frost is uncommon, and it is smart to maximise your zinnia enjoyment by sowing as quickly as you may.
Even in case you have some leftover from summer time, shield them in a frost to see for those who can proceed to develop them when circumstances enhance. Day size does reduce in winter, however the temperatures and potential rain enable for tons of pretty flowers.
Key Takeaways
Keep in mind, your season size and your final frost date are the keys to the best timing. Use your zip code to find out a extra correct however nonetheless approximate date, and sow your zinnias one to 2 weeks earlier than your final frost.
Once you’re deciding how lengthy to attend to start out zinnia seeds, take into account this chart.
| USDA Hardiness Zone | When to Begin Zinnia Seeds |
| 2 | 1st week of Might |
| 3 | 1st week of Might |
| 4 | Final week of April |
| 5 | 1st of April, or within the final week of March |
| 6 | 1st of April, or within the final week of March |
| 7 | 1st of April, or within the final week of March |
| 8 | Mid March |
| 9-12 | Any time; February is an effective start line |
Be aware which you can begin your zinnia seeds earlier than your official final frost date, however for those who reside in a zone the place snap freezes can happen after that date, hold a canopy helpful to guard seedlings via the freeze.