Zinnias die after planting....Help

10 years ago

I grew several hundred zinnia plants from see this Spring in my greenhouse and they have been oing great. I planted one flat of the plants last weekend in the garden beds.
Every day I see more and more of them dying.
The lower stems shrivel up, turn brown and the plant collapses. Any ideas?
I don't want to plant the other ones yet.
I have planted other annuals (marigolds, vinca, begonia) in the same beds nearby with no problems.

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Comments (4)

docmom_gw
10 years ago
I'm so sorry that you are having such awful luck. It looks almost like someone sprayed them with weed killer. Did you put down any chemicals before you planted them out? Have you grown zinnias in that spot before? How much water are they getting? It is possible to over water plants and cause them to wilt and die. Hopefully others will have good ideas of what is going on.

Martha
ken_adrian Adrian MI cold Z5
10 years ago
one thing i would note.. i would have planted them at about 1/3 the size ..

your seedlings look glorious in those cell packs.. but they are way beyond planting size ... THIS TIME OF YEAR ... are they going to have enough time to adopt their roots.. with that size plant.. before the heat of summer hits????

what i suggest.. FWIW ... is to start them a couple weeks LATER ... so that by frost free time... they are no bigger than half that size ...

now.. the only issue is.. whether you took copious notes.. and know when you started these .. lol

my only observation on the dead ones.. is that the top is green.. and the stem looks rotted ... suggesting.. wait for it.. a stem rot.. lol.. i dont even know if that is a proper term...

good luck

ken
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rhizo_1 (North AL) zone 7
10 years ago
Sun scald?
zen_man
10 years ago
Hi rodco,

You have made some good close-up pictures of the problem. In my opinion, your zinnias are dying from either Watery Soft Rot or Southern Blight. Once a plant becomes infected with either fungus, there is no way to save it. So prevention is key.

Watery Soft Rot is an infection by the fungus Sclerotinia sclerotiorum. It starts as a water soaked area on the stem near the soil line and as it spreads upward, leaves die, wither, and the plant droops to the ground. The fungus lives on plant debris or in pellets in the soil.

Southern Blight is an infection by the soilborne fungus Sclerotium rolfsii that occurs primarily in the southern states. It usually attacks plant stems at or just below the soil level. Infected plants wilt, turn yellow, and decay as the fungus spreads throughout the roots and stems.

If I had to guess, I would say that your zinnias are being killed by Watery Soft Rot, and the fungus is in that mulch material. You could scrape back all of that mulch material to expose just the soil below, and try planting in that. If the fungus still attacks, you need to find a spot that isn't infected by the fungus. Zinnias like a rich sandy loam in a spot that has at least eight hours a day of direct sunlight.

ZM