Seedlings dying right after transplant to potting soil

Hi,

I’m new to this forum and was looking for some advice.

I recently transplanted a batch of healthy seedlings from the seed-starting mix in which they germinated into regular four-inch pots filled with sterile Whitney Farms potting soil with a small amount of slow-release fertilizer. Soon after, a large number of the seedlings began to wilt and die, and it looks like I will lose most of them.

I’m not sure what the problem could be. The seedlings germinated and sprouted outside, so I would have thought they’d be used to the relative humidity, they were of a decent size (most had at least two sets of leaves) when I transplanted them, and they had plenty of water. I was extremely careful to not touch the roots in any way when transplanting (I literally buried the little peat pots the seeds were in directly in the new potting soil - I didn’t dig the seedlings out).

Does anyone have any ideas as to what I might have done incorrectly? I live in the Pacific Northwest, so it hasn’t been overly hot, and I kept the transplanted seedlings out of the rain so they wouldn’t get waterlogged.

I couldn’t find a way to insert more than one picture or URL, so I’ve pasted in links to images illustrating what I’m describing. The first picture shows the healthy seedlings in their seed-starting mix and peat pots.

http://pic20.picturetrail.com/VOL1218/5581325/11127472/321644299.jpg

The second shows the average size of the seedlings before I translplanted them.

http://pic20.picturetrail.com/VOL1218/5581325/11127472/321644298.jpg

The third shows what has happend to the seedlings after transplantation.

http://pic20.picturetrail.com/VOL1218/5581325/11127472/321644297.jpg

Any help would be greatly appreciated!

Thanks!

I would say the slow release fertilizer in your mix is hurting them. I don’t believe anyone uses any kind of fertilizer on new seedlings. I would change to any kind of germinating or transplanting soiless soil without fertilizer. Good luck.

Patrick

Sorry for your loss. I had the same thing happen to me on 12 seedlings this year. The seedlings were healthy when started in their Pro Mix and I transplanted into larger pots using Miracle Grow potting soil. They died within 2 weeks. Thankfully I only did those few and have used the Pro Mix exclusively on all other seedlings with no adverse affects. The Miracle Grow potting mix had slow release fertilizer, big chunks of “stuff” and molded when wet. It was labeled as a sterile seed starter so I thought it would be safe.

Don’t be discouraged. We’ve all lost promising seedlings, usually when we’re doing what we think is our best for them.

Lori

Hi Saori,

I agree, it is probably a soil problem. Several years ago though, when I was using peat pots, I had a lot of damp-off, so I switched to plastic.

Jim Sproul

Miracle Gro potting mix is FAR too hot to be used on seedlings. Way too much readily available fertilizer in it; it will fry the roots. Try to avoid anything that says it has slow release fertilizer, or any fertilizer additives in it at all. Organic components don’t count as fertilizer.

Something else to consider: some seed parents produce offspring that are unusually tender in their first few months of life. I work with a certain Ralph Moore breeding plant which is a R. wichuraiana seedling. It produces seedlings that will frequently flop over and die if transplanted at the 1 to 5 leaf stage. I have learned to leave these in the germination trays until they have a minimum of five leaves before I transplant them. At that stage, 95% of them transplant OK but if I move them when they are smaller, 75% of them will die, guaranteed. So perhaps you just have some finicky seedlings from a certain parent. Try leaving them till they are bigger before you move them.

Paul

Hi everyone,

Thanks very much for your help! I wish that I had found this forum before transplanting my seedlings…

This is only my second year to try breeding roses so you can imagine how excited I was to find that I had more than 50 seedlings coming up this spring. (Last year, I only had three open-pollen seedlings; even though I’d tried to breed quite a few, none of those germinated.)

I’m pretty new to rose breeding, so I don’t really have any idea yet which parents would tend to produce finicky seedlings, but my goal was to produce some brown, grey, or lavender blooms with a large number of petals. I mainly used some of my favorite David Austin roses for seed parents, and for the pollen parents, I used “Grey Dawn,” "Caf

Practice makes … almost perfect :slight_smile:

i to used miracle last year a they died too. i’m so glad you guys and ladies are here!. i will file this in my head for february. no fertilizer leave in pot longer.

also been talking to frank bernardella about not fertilizing rose after crosses

which is a big help to know!. also nor- east has just put out more of franks roses like double take, deja vu,and two more.