They say zinnias don’t transplant well, but I still prefer to start mine indoors to control placement and colour in the garden. Having said that, I’m still playing with how many weeks before frost so the new starts are not too leggy and stressed when planted out after risk of frost has passed.

This is my personal growing guide. I use it to track seed sources, when to start seeds and if I should adjust growing conditions in my own greenhouse and garden. Please don’t consider this professional grower’s advice.

Current Varieties and Sources

I’ve grown State Fair, Benary’s Giant, Profusion, Preciosa, Art Deco, and Cactus varieties. My problem is I keep forgetting to keep good records of how they perform however what I do remember:

• Art Deco was lack luster, nowhere near as colourful as the pictures so very disappointing
• State Fair is a good performer but I don’t like that I can’t control colour placement in the garden
• Profusion is good in the garden but needs frequent deadheading by August if you want to keep the colours vibrant

Garden Design

In 2026 I am limiting my zinnias to Benary’s Giant in a few selected colours.

In previous seasons, I’ve treated zinnias more like a feature, planting them en masse for impact either in the garden or in raised beds. While dramatic, planting zinnias this way takes more maintenance than you think if you want the area to stay fresh looking.

This year, I want something softer.

Rather than creating blocks of colour, I am going to tuck individual plants and small clusters throughout the garden, weaving them among my other shrubs and perennials. The goal is a more naturalistic look: tall stems rising unexpectedly through existing plantings. Benary’s Giant is ideal for this. The strong stems and large blooms allow them to hold their own among shrubs, while the height lets them float above surrounding foliage without overwhelming it.  I’ve selected colours that work well with the rest of my garden design.

Swallowtail Garden Seeds

• Benary’s Giant – packages each of Coral, Pink, Scarlet, Wine, Lilac, Purple, Deep Red – I prefer single coloured packages not mixes
• Benary’s Giant – Carmine Rose (new for 2026)

Seed Starting Guide

I notoriously start too early. Our last frost date is around May 13 according to the almanac however it’s rare for us not to have a cold snap before the May 24 weekend. So for 2026, this is my new schedule:

Start Date

• April 15–20 (4–5 weeks before May 24)
• Germination temp: 21–24°C
• Days to germination: 4–7

Sowing Method

• Sow directly in cell packs
• Cover ¼ inch
• Do NOT like root disturbance
• No potting up

Growing On

• Temp: 18–22°C
• Light: 14–16 hours
• Fertilize when 3 to 4 weeks old.

Planting Out

• Frost tender
• Wait until after May 24
• Can also direct sow late May
• When transplanting in the back garden, cover for the first few weeks with wire or rabbits & squirrels will dig them up.