No to the plastic. If you must use anything use floating row cover. You don’t give your location or climate but as long as it isn’t going to get extremely cold very quickly plant the Vinca. It’s just as hardy as the box.

Btw you could have mulched the whole area first and then planted the Vinca through it. I don’t think the Vinca will fill in ‘thick’ for a couple of years, at least not if it grows at the same rate as it does in my climate. A Dutch hoe is a good tool to have at the ready for dealing with infant weeds.

yes, zone 6 or 7 new jersey sorry didn't add

From what i've read, vinca minor will fill in thick within a year if planted about 6 inches apart, but if spaced 18" takes a couple years. Don't know if that's reference to 6" pots or mini starter cells I used.

I'm thinking if I mulched the bed first, then as mentioned, the vinca won't be able to root through it as quickly in order to fill in thick. I know the vinca will quite easily root through a couple inches of grass clippings mulch but I just think it'll spread quicker without mulch.

Maybe I'll get lucky and the soil there isn't too filled with crabgrass seeds. Because I tilled it about 8" and most CG seeds sprout from the top inch of soil. Yes dormant CG seeds will stay active for many years if burried but I just hope the soil down 8" is less filled with CG seeds. I did play around with the dirt a bit though, added some back in, and not sure if that was from the top layer or not. Lawn wasn't too bad with CG before I tilled it but it did have a decent amount at one time.

good to know you think the vinca is at least winter hardy, so I'm not too worried about it. As long as I get some to spread nicely, I can always just propigate more off of that, but if in spring it's obviously dead then I will replace it.

the vinca starter cells were planted too close together to get in there with a dutch hoe or action hoe or anything. If anything, would use a string timmer used upside down as an edger but prefer to hand pull roots out. not sure what would happen if roundup were painted on anyweeds which may pop up in the meantime but will probably test a spot if so.

I'm not sure if the plants are too young to do so but when my strawberry plot was 1 year old (started in Spring from bare root) I put a good 10" or so of dry hay over it all winter and in spring it didn't look as though it was damaged at all (from locked in heat and moisture or something), but the next year I didn't mulch them and they were just as ok in spring, but were more mature by then.

Maybe I can put some straw over the vinca but the roots are so small, plus are currently probably fightign off transplant shock that I'm afraid to mulch over them but I will look into that floating row cover you suggested because it seems to be a possible option. thank you

Vinca roots into several inches of mulch without problems IME, in fact far too enthusiastically for my tastes, and so I am working to remove mine. I would mulch the beds around and between the plants as floral suggested to decrease the chance of temperature swings and frost heaves. In the other beds yet unplanted, put down mulch and then pull aside for planting the individual plants. The time involved will be far less than mulching after. Mulch will help keep the beds evenly moist and the temperature swings will be far less as well as suppressing weed germination. And Vinca survives to below -20 F in my garden, so you have no need to worry about cold hardiness in your zone.

I am most concerned about your statement that you tilled the lawn. Did you kill or strip the grass first? If not, you will have grass to contend with, and the Vinca won’t be able to suppress it. Regardless, IME you will have crabgrass and other weed seeds to contend with on any exposed soil. It is far easier to prevent weeds than remove them, and that is one of the most imporatnt jobs of mulch in a new planting.

unless they are put in the ground most likely they will die .

You might consider covering the ground between the plants with several layers of newspaper to keep weeds down. Then just cover the newspaper with mulch.

I just googled 'too cold to plant vinca minor' and found my own thread I kind of forgot about.

I don't think they did so well over winter, or maybe it's too early to tell. EDIT: yes too early to tell, and when I originally posted this few nights ago wa sa bit dark to tell, went back the next day and although some appear that the leaves and stems are brown/dried etc, there is new growth on them and the starter cells have expanded their roots a bit. They should be fine.

The grass is just starting to grcome ot of dormancy now.

will be putting sprinlkers on the vinca.

Linked below is suggested to put plastic (plus mulch) if have harsh winter (like NJ, although it barely snowed this winter which is good). But I just started some herbs and vegetables indoors and put plastic over them at the start, and some things sprouted in only about 3 days but already had fuzz mold growing, so i removed the plastic which was used to hold moisture and reduce watering (misting to not disturb rooting of tiny seeds). I don't think plastic OVER the vinca would have been a good idea either now.

The next 2 links suggest to mulch over them before Winter (like I did my strawberry plants a couple times but skipped the 2nd year and they were fine).

I see vinca (and pacysandra and english ivy) all the time though around here and it's fine without ever being mulched over, it's just that these are starter plants is the main factor to mulch or not. I guess the reason I didn't just throw mulch over them is I think they're too immature to handle possible mold/fungus caused by mulching (when I removed the hay mulch from my strawberries one year there was a ton of mushrooms but they did fine but were already a year established).

https://www.gardenguides.com/104795-winterize-vinca.html

https://www.nurserymag.com/article/amleo-cold-tolerance-ornamental-overwintering/

This says mulch AND heavy plastic but is SFgate... eh, not the greatest source of information always.

https://homeguides.sfgate.com/can-overwinter-vinca-73402.html

this shows winter damage all brown and unmulched but came back fine:

http://www.itsnotworkitsgardening.com/2012/04/vinca-loves-mild-winters.html

Another thing to note is that the soil really should be rolled/tamped before planting the starters, because around December we noticed basically the soft loose soil which was tilled started to compress naturally from rain etc and basically left a lot of the cells pratically unburied, at the top, so I reburied them. Now it looks like the same thing happend again but not as bad, though a second time even though I already reburied them and packed the soil around them (ground was frozen though the first time I re-buried.

I will put grass clippings from the first mowings in between the plants to keep weeds down. I was hoping it roots so fast that I could get away with just pulling or weedwacking (on an angle in tight spaces to not clip the vinca runners) if anything started to interfere but I'm now convinced that the vinca runners root so well that they'd root right though a couple inches of grass clipping mulch. Also am convinced as suggested to mulch it all first then install the plants over the mulch.

Even if I planted them about 4-6 weeks sooner, the cold could still be a problem and I'd be hesitant to mulch OVER tiny starter plants, so it seems Spring is better but will need more watering to keep up with the heat (although the extra roots you get from a fall planting the year before isn't going to make them drought tolerant in a full sun application - it should be watered frequently on a timer the following season regardless.

Seems better to plant these in early Spring because then you don't even have to worry about if mulching over them will harm them or not. It's not like a few inches of mulch is going to stop it from freezing anyway, but it'll help.

This is an experiment I'll have to run next Fall - plant some in all the different variations mentioned , in the same area so getting the same shade/rain conditions (except no plastic sheet method, but floating row cover sounds promising but maybe not pratical for a large area- also not newspaper since I want the vinca to root down easily through the mulch).

I'm also doing another small area in a couple weeks so that'll let me know how Spring planting vinca minor goes (with sprinklers,, and milorganite).

Some cells appear to be just soil as if everything died but the roots have expanded and there's new tiny growth happening, I even see a few flowers starting. I think it's ok to plant in Fall and NOT mulch OVER them but still Spring seems more pratical and also no one will freak out and think it died over winter, but yes Fall planting will give a bit of a headstart on rooting (which will them probably encourage quicker spreading that you want) and these didn't die over winter.

I would strongly advise against using plastic for many reasons. One of which is that Vinca minor spreads by rooting along the stems where they touch the ground. If you put down plastic they can't root. At least not until the plastic is covered with leaf litter and debris. And at that point weeds will also be growing it. Don't put down plastic.

^ I was asking about platic OVER the vinca sort of like a greenhouse for winter to prevent frost damage. I wouldn't do it though because on second thought it might trap too much moisture and then could start a fungal disesase or something. Maybe if the sides were open like a greenhouse for some airflow (but not so much that it negates the whole purpose) then maybe it wouldn't cause fungal/rot but if anything I'd just put leaves/hay mulch over them for winter and then remove that mulch in Spring. Or use the floating row covers.

They seem to have done ok with nothing mulched on them though, I edited my post two posts back , there's new growth coming from cells which looked like they died when I saw them at twilight. I'll post back if it doesn't work out. I wouldn't put plastic or landscape fabric, cardboard, or even newspaper was suggested in order to keep weeds from forming before the vinca can fill in - vinca roots agressively but even newspaper in the way of it would probably be a problem. Best practice is mulch the area first with grass clippings, bagged mulch, leaves, hay etc, then plant the starter plants in the mulch and keep the mulch a couple inches away from the base of the plants so it doesn't hold moisture there and kill the plants (when the growing season starts especially, during winter dormancy it can probably handle all the moisture on the plant base stems i.e mulching over the whole thing like a strawberry patch which is often done even on commercial strawberry farms.

“vinca roots agressively but even newspaper in the way of it would probably be a problem. Best practice is mulch the area first with grass clippings, bagged mulch, leaves, hay etc, then plant the starter plants in the mulch and keep the mulch a couple inches away from the base of the plants so it doesn't hold moisture there and kill the plant”

I have had vinca growing for more than a decade and it has no issues with rotting with mulch right up against the stems, and it roots readily through a heavy layer of cardboard with mulch on top, so even 15 layers of newspaper wouldn’t stop it. It will root right into the newspaper. Seriously, you are worrying unnecessarily; this is a plant that will cheerfully take over the world if given the chance, and I have been unable to get rid of all of it though I have been working on it for several years since it doesn’t play well with other plants. Maybe this year the last of mine will be ripped out. It roots into sod, other plants, cracks in rocks, mulch, etc.

ok so it CAN root through newspaper and even cardboard you're saying, but it's would spread and root and fill in faster without all that in the way. If weeds are that bad a problem then maybe newspaper/cardboard but I would just stick with good ole grass clippings or stray/hay wood mulch, or some hand pulling/weed wacking (on an angle to slice/wack downward and not cut the vinca runners all up).

As much as I hate chemicals, I read a lot of people complain they rip their vinca out year after year, but just spray it, likely weed wack it first and make open wounds, usually herbicide is taken in by photosynthesis of the leaves but I have read possibly even on product labels for brush and ground vines that cutting it before applying will knock it out more effectively. Lots of people consider it a weed or something, true in the woods it's not good because it'll just keep spreading and wildlife won't even eat the stuff, but groundcovers are a Fantastic mulch replacement instead of re-mulching and de-weeding year after year.

I agree that groundcovers are fantastic. I just don’t like vinca because it spreads into places I don’t want it.