Well, I've never grown Vinca, but I've read that it can be very slow to grow. Two or three months from germination till large enough to transplant is not uncommon.

Your theory of low temperatures could be correct. According to the University of Georgia College of Agricultural & Environmental Sciences (see link below), the grow rate of Vinca is greatly influenced by the temperature of the soil. They suggest keeping night temperatures above 75 degrees. Reading their webpage should give you some helpful ideas, but I'm thinking that maybe you should try increasing those night temperatures somehow?

Art

Here is a link that might be useful: Vinca Growing Guide

Art,
Thanks. I wouldn't be surprised that it is soil temperature related. The complicaiton is getting the soil to that point. Ambient temperature at night is the temp in the house...which is upper 60's.
I do have a heat mat for germination. I might have to use it under them for a while. I'd love to put them in my pop-up greenhouse outside, but the night temps would still be much too low.

Vincas grow super slow after they've been chilled when they're little. If you can get it into 80 degrees or so and keep it pretty dry it will grow faster

So, what is this color that you are growing that you have never seen in the stores?

I started our vinca 2-14 under lights in the basement and they are blooming now. We grow them every year but this is the best result ever-they are absolutely gorgeous. They are also both new types this year- Titan Mix and Cora Cascade. Now I just have to be patient and not bring them out too soon.

The variety is called Jams N Jellies. It's a very dark purple. The pictures look nice...we'll see if I get blooms :)

I placed the pots on my heat mat in a sunny window, and now that the weather is milder, I've been placing them in my popup greenhouse outside during the days. Still a little too cool for evenings, so I bring them in. They seem to be growing a bit faster now.

I'm growing the Jams N Jellies, too, and I've also noticed that they are growing slowly. They do have some nice side shoots that are growing very slowly. I actually saw these in a local shop's window box, and they do look nice in bloom. That was the reason I bought the seeds this year. My seedlings are also very short, but they look sturdy. Here's hoping they start growing once they go outside full time!

Here are pics of my vinca seedling volunteers. The one in the 4" pot came up last summer, the ones in the pot with the large one came up about 4-5 months ago and sat there through our winter, and most haven't started growing yet. They are various sizes, so some are growing.

Very pretty! I wish that I lived in a warm enough climate to have volunteers.

The Jams & Jellies is a new variety, which explains why you haven't seen it in Garden Centers. Retailers wouldn't have had it in production until this year

hmmmm, vinca, in the UK, usually means periwinkles - an evergreen groundcover, either blue or white.
Are the US varieties some sort of catharanthus? Yet to gain traction in the UK market.

I started Jams N Jellies the last day of December. Information I gathered from gardening sites on the web said that they are slow growers, and they are. I now have full sized plants that are blooming. I made the mistake not to label them and planted 2 types of vinca so I had to wait until they bloomed. I gave some away to my mother and sister on Mother's Day that were not blooming. Some of the ones that I kept have since started to bloom inside under grow lights and I see 1 is jams N jellies. This is my first time posting on this site although I have been reading post for almost 2 years. I was excited to hear that someone else was growing vinca jams N jellies. I will try to post a picture tomorrow. It felt good to go to Home Depot and see their Vinca and see that the ones I had grown at home look just as healthy and full as theirs. I will never pay for a vinca again except for seeds.

This post was edited by amsonia2 on Sat, May 18, 13 at 20:10

Looking a head. You are growing an interesting color. You may be happy with results, or not. For some real fun, collect seeds from plants this year and plant them next year. Here is an example of that. From one plant I got this nice mix a couple of years ago. I try to get seeds from an interesting hybrid and see what those scrambled genes produce next year.

flora there not talking about the groundcover, Huhhhhhhhhhhh, latin and common names can be confusing can it be flora

I am growing a variety of Vinca in Malaysia. They do very well from cuttings but are very slow to grow from seed. I have had some seedling for three months and although they look healthy and green their growth progress is very slow. They are kept in a temperature of around 30C which is the normal daily temperature most of the year round here. I used grow lights to encourage growth on some of them but it does not seem to make any difference.