My experinece is - If you transplant while they are young (first true leaves) you can plant pretty much anything as deep as the cotyledon leaves without a problem.

I'd be wary of this with Catharanthus. They can be a bit touchy when it comes to transplanting. Those lower leaves need to be high and dry. Worthy of a try, but I'd not hold my breath.

(You are talking about Catharanthus roseus, right? Not the 'real' Vinca major or minor?)

NO! DO NOT plant vinca seedlings deeper - it's rot waiting to happen, annual vinca rot very easily if planted too deep and/or soil is too moist.

I would make sure the lights are only about 1-2" above the top of the leaves. They are getting leggy because they are reaching for light, so make sure the lights are right above the leaves.

mxk3, fyi, these vincas aren't annuals. They are tender perennials. I've had one for 3 years now, and a couple of others are more than a year old. It hasn't gotten cold enough to kill it, and it's blooming right now.

Are they Catharanthus roseus? If so, that is the vinca to which I am referring. It is annual in my zone (and we are on the annuals forum...); I do believe it is a perennial in warmer zones (not sure which zones, though).

There are other types of vinca which are true perennials in my zone.

If you're growing Catharanthus - I stand behind my advice. Do not bury stems.

Here is a link that might be useful: Catharanthus roseus aka vinca

This post was edited by mxk3 on Sun, Mar 24, 13 at 14:55

I havent grown them - so maybe best to ignore my advice. I havent had an issue with a variety of other seedlings being transplanted deeper, but Rhizo & mxk3 sound like voices of experience.

Because this plant (Catharanthus) is so often used AS AN ANNUAL, it is very commonly called "annual vinca " to differentiate it from the perennial, woody vines Vinca minor and Vinca major.

It's helpful to remember that many plants commonly referred to as annuals are not true annuals. A plant can't be a perennial in a warm climate and an annual in Michigan. It's simply a tender perennial that
serves AS a useful annual.

We're all on the same page, clearly. It can be confusing sometimes. But it is clear to me that mxk is talking about Catharanthus when using the term "annual vinca ".

Thanks for the replies! These are not "major" or "minor" the vine type, just an annual in our area because of the winter temps. The "leggy issue" was because they germinated in about 1/3 of the time the package said to expect, and grew tall in the bag searching for light. They started greening up within 24 hrs of being put under the lights which we try to keep as close as we can. None of them have wilted or appear to be under duress. I understand it was not an ideal start, just wanted to know if I could lower them when I transplant to offset the height difference. I will pay much closer attention next year! First year growing flowers from seed, and it's like learning how to garden all over! I have Carnations, Vinca's, trailing Petunia's, Impatiens and Zinnia's.

"A plant can't be a perennial in a warm climate and an annual in Michigan. It's simply a tender perennial that
serves AS a useful annual."

Are you a lawyer? LOL!

For next year: The bag is unnecessary if the seeds are covered by potting mix. The mix keeps enough light out. This is my second year growing annual vinca aka Catharanthus roseus. I didn't use the black plastic and they came up fine both years.

Yep, the black bag was your undoing. I don't use plastic of any kind unless the seeds require sunlight in order to germinate...that's when it's a good idea to create a humid environment during the germination period.

mxk3, yes, that's what I have, that's a perennial, not an annual. An annual is a plant that blooms for a season, then goes to seed and dies. These do go to seed, I have a pot of white ones that have just sprouted, and the parent plants are still in bloom. They are tender perennials, but most people think of them as annuals. I did, too, until they didn't die over last winter, and are still going strong. I also have impatiens that survived the winter (with help, I brought them indoors when it got too cold), so I guess that they are tender perennials, too.

We're arguing semantics - these are tender perennials treated as annuals in my zone; therefore, they are referred to as annuals up here.

Which makes the case for using botanical names, not common names :0)