Martha

Remy,

"A rule of thumb with seeds is if they are good, they will be hard, as you noticed with the seeds on the right, thick and ridged. Bad seed will be thin and easily bendable."

Well said. I use the bend test to determine whether a zinnia seed is "empty" or whether it contains a developed embryo. You can also lightly pinch a seed to feel whether it contains a developed embryo and endosperm, or if it is just an empty husk.

Incidentally, in the picture above, the seeds on the left are floret seeds and the seeds on the right are petal seeds (with a couple of exceptions). Floret seeds develop at the base of the star-shaped yellow florets, while petal seeds develop at the base of petals. Floret seeds can be viable or not, just as petal seeds can be viable or not.

I am a zinnia hobbyist, and I do some of my own cross-pollination, so naturally I save zinnia seeds. I like to get two generations per year in my outside zinnias, and two generations per year in my indoor zinnias, so in order to shorten the seed-to-seed time, I save "green seed" from still living petals. This picture shows how to tell the difference between viable green seeds and "empty" ones.

By planting green zinnia seeds, I can get new plants into bloom several weeks sooner than by waiting for the petals and florets to turn brown and "dead". You can either plant the green seeds immediately for quick turnaround, or dry them out for storage and use at some future time. Another advantage of saving green zinnia seeds is that you avoid losses to pregermination in brown seedheads in rainy weather. If you see a little dried rootlet sticking out of a brown zinnia seed, it is a "goner".

ZM

Northerner,

It takes a little practice doing the bend test, because you can break a good seed if you bend it too much. When there is some danger of breaking a delicate seed, I use a gentle "pinch" test to verify that there is some "content" in the seed without flexing it much. The seeds in this lot required a lot of gentle pinching as an alternative to the bend test.

They were saved from an unusual "Pink Shaggy Dog" zinnia that had a lot of long narrow petals. I have noticed that there is a lot of correlation between seed shape and petal shape. As you can see from this picture, the Shaggy Dog zinnias have some extra long narrow petals.

I plan to use Tissue Culture techniques to germinate some of the long thin seeds from the Shaggy Dog zinnias, because I doubt that they contain enough endosperm tissue to support normal germination. I'll be experimenting with the Tissue Culture of zinnias this Winter.

ZM

Northerner,

"Now I'll be searching for seeds for them."

If you mean for a commercial strain of zinnia called "Shaggy Dog", you won't find it. That is a name that I coined for one of my hand-hybridized zinnia specimens. If you mean searching for them in your saved zinnia seeds, then, yes, that is a possibility. Zinnias have all sorts of interesting surprises in store, and no telling what you will find in your zinnias.

The Shaggy Dog flower form is unusual, because as the flower matures, it gets really "long" or "tall" instead of wide, as you can see in this picture.

"I picked up a couple more zinnia heads which I believe were Shaggy Dog types. The petals were long and thin, and the seeds were still attached to the petals when I took the dried seed heads apart."

It is possible that you might find your own "Shaggy Dog" type of zinnias. The ancestors of mine were simply commercial Burpee Hybrid and Burpeeana zinnias. I grew quite a few and cross-pollinated a few selected favorites that had extra long thin petals. I grew those hybrids, and then made hybrids of the hybrids.

However, I was trying to get a spider flowered strain, and the dangling flower form of the Shaggy Dog zinnia came as a complete surprise to me, and was unplanned. But I immediately liked it, so naturally I self-pollinated it as much as possible and saved seeds from it. We'll see what I get from those seeds next year.

"I will have to try your 'pinch' test next fall when I am saving. Don't know I can really tell if there is "content" with my limited experience, but I guess with the interest your responses have sparked in me, I may get there some time."

You will get there. It is just a matter of shucking out and handling a lot of zinnia seeds.

"As for "Tissue Culture", that's way out of my league."

For a lot of people, Tissue Culture is a hobby all by itself. I was drawn to it more for what it could do to improve my zinnia hobby. However, as I get into it, I can see the attraction. There are many aspects to Tissue Culture and it can be as simple or involved as you want it to be. It is actually fairly easy to get started in Tissue Culture, and the Home Tissue Culture Group and their kits are a good starting place.

ZM
(not associated with any product or vendor mentioned)