You can certainly use pots to cover your plants. No need to cover the holes. Better yet, dig them up (at least the coleus), repot and wait until not only the weather is warmer, but the soil is too. Coleus will not like cold soil one bit.

The weather has been mild to warm, ranging from upper 50's to upper 70's. Just a day or two here and there that cause for concern. Not sure how warm the soil must be. Oh the joys of spring.

Covering your plants should do the trick. If you do cover the holes, it will trap the warmer air that will come from the soil, creating a nice little protective tent.

It's always a good idea to check with your local extension office to find out what the AVERAGE last frost date is in your location, if you don't already know. Then plant tender plants a couple of weeks after that! That date is a good guideline and will prevent you from jumping the gun when spring fever hits.

The one thing you shouldn't do is to judge good planting times according to what the local weather is doing lately. Best to consider that long established average last frost date.

And please, especially in your zone, don't trust seeing them suddenly appear at box stores and super markets as any indicator it's safe to plant them. They appear earlier and earlier every year to try to catch the market. It's monetarily driven, not culturally. I saw tender annuals like impatiens and marigolds outside of my food market in mid April. It's frosted at least four times since then and I'm a zone warmer than you and I'm not considering it safe for those until mid May. Especially things like begonias. They're especially tender.

Don't mean to beat up on you, as what's done is done - so take these posts as a learning opportunity.

Agree with Calliope's post above re: when annuals turn up for sale.

I don't even consider planting annuals until the middle of May, even then it's iffy and weather-dependent, and a lot of times I plant the last week of May.

Even if temps are okay and are not predicted to dip low, have to take into consideration how warm it has *been* (re: soil temps) and how wet the soil is. Cold, wet soil is death to annuals, and it's common even into May - don't let warm sunny days fool you, if in doubt invest in a soil thermometer and check, and check the soil to make sure it's not too wet.

Soil in pots warms faster, obviously, and also dries out faster, so often can get away with planting in planters mid-May or so, but again - have to check the soil.

April/early May is tree/shrub, and perennial planting time, it's a different ballgame for annuals in colder zones. :0)

it would help if we knew where you are ...

in my z5 .... the for sure no frost day.. in my 30 years ... is about 5/25 ... yeah.. really ... you were only about a month early ....

BUT!!! .... kansas city is also z5 ... and i bet its early may ..

so you need to figure out when your most predictable frost free date is .. and live by it ...

mother nature is a cruel ***** [mistress] ... you dont mess with her.. lol

as noted.. call the county extension office.. ag office.. or soil conservation office.. and ask.. heck.. call all 3.. and see if the answers are the same.. for last frost date ... i tell you.. those farmers know everything about the vagaries of nature.. or at least they think they do .. lol

ken