I pulled one out and filled the hole with water and it drained
readily so I don't think it was that they were too wet. Maybe they got
too cold? Maybe the pH was wrong? Idk.

I want to replace them but I don't want the next thing to die too. What can I plant in a container that is evergreen, mounding, and stays relatively small? The area is south-facing, gets full sun half of the day then is partially shaded by house and trees. And boxwood is OUT. I cannot stand the cat pee smell of boxwood. Building a raised bed or planting in the ground in this area is also a no go. It has to be something that will thrive in NJ 6a in containers. Ideas?

Thanks!

Very likely froze during your winter, which, if the news is to be believed, I understand was pretty wicked. And still is in some cases :-)

Plants grown in containers are exposed to much colder temperatures at the root zone than they would be if planted in the ground. And the roots are the most cold vulnerable portion of the plant - damage can be experienced at temps of right around the low 20's for many (if not most) woody plants and it only takes a night or two at those temps or lower for the damage to be fatal. Even the rule of thumb that you should select plants for permanent containers that are hardy 2 full zones lower than yours is no guarantee.

if that todays pic.. i think i see some green .... its a bit early in cold zones.. to be presuming death ...

besides what gal said ... there is also excessive water retention if the pots froze solid .... roots need air winter or summer ...

as well as possible fert issues if your put a lot in at planting ....

and also .... any recall how fall went .... was it nice and gradual into dormancy.. or was it 50 one day.. and zero the next ...

there are all kinds of variables ...

but what is most confusing.. is total loss ... the odds of that are low .... im going to have to ponder this part .. you would expect at least one to survive ...

btw.. whats under the snow ... pavement??? .. thats a whole other variable ...

lastly.. why could they go in the ground ... ken

ps: if bigbox... which is another variable ... you might get replacements .... we cant rule out stock problems ....

Ken, if the pots froze solid, the plant roots did too. And frozen roots are dead roots!! And flash frozen roots can result in a very dead looking top growth very rapidly.

Conifers seem to be more resistant to extreme cold in containers than any BLE, so choosing something like a dwarf arborvitae or dwarf Alberta spruce should be successful. Just make sure they are listed to at least zone 4 (and lower is better) for your greatest chance of success.

The exposure is going to be a problem. Quite possibly the biggest problem. In general, broad leaf evergreens do better with shade during the winter to reduce dessication issues. Frozen roots aren't necessarily dead roots, but frozen water isn't any better than no water. So the trick is to find something that can handle sun and extreme drought. Around here, the most successful evergreens in pots are dwarf Alberta spruces, but even those can have problems with a real winter.

This is a long way of saying that I don't think your solution is going to work. An explanation of the problem you are trying to solve may come up with an alternative solution that can work.

"Frozen roots aren't necessarily dead roots"

Sorry but I am going to disagree with that statement. When the water/fluid inside the roots freezes, it destroys the root cells. Plants do not come back from that sort of damage. One seldom ever encounters this with any inground planting as soil temperatures do not reach the same bone chilling cold as the ambient air temperature and don't often drop much below freezing unless exposed to very cold temps for weeks at a time. The soil mass actually acts an insulator, protecting the roots from extreme cold.

Roots freezing in the ground are uncommon. Roots freezing in a container are unfortunately very common. That's why so many suggestions are made to bring containerized plants into a protected location for winter in colder (lower than zone 7) locations.

Nope.

Subzero temperatures with no snow cover = frozen ground fairly deep. Look at the frost tables for cold climates. So what you are saying is that any plant that doesn't have roots several feet deep into the ground under those conditions is toast. Sorry, but Ohio is not a desert.

Why are containers needed as opposed to in ground planting? Why do they need to be evergreen shrubs? Seasonal annuals along with cut evergreen branches for winter might be a better solution if in ground planting isn't possible for some reason.

As mad gallica said, giving us the problem that needs to be solved may get you some creative alternatives. The only thing I've planted to successfully overwinter in a whiskey barrel planter is ribbon grass which is a deciduous perennial.

Soil does not freeze to the same cold levels as ambient air temperatures. The soil itself does not freeze - it's the moisture it contains that freezes and we just don't live in an environment that gets super chilled ice. It takes weeks of subfreezing temps for the soil temperature to drop much below freezing. And it is always heated/warmed from below - there is a temperature gradient with soils, with the top layer - exposed to the air - tending to be colder than deeper. "Frozen ground" at 32-30F is not at all the same as a -5F air temp. And few roots will freeze at those soil temps.

I worked with a soil scientist digging holes in the woods (fairly protected by leaves and plants) one snowless November, and we regularly found frozen ground down most of a foot. In a time with little snow and extended cold that doesn't get out of the single digits, it isn't unusual for frozen soil moisture to extend well below a foot here. All old cemeteries in my area have a stone building that dates from before diesel digging machines where bodies were stored until graves could be dug after spring thaw, so that gives some ideal of the depth that roots are exposed to below freezing temperatures around here, even in the ground.

There are IME more plants that don't do well with the kind of really cold root temperatures that occur in a container vs those that will tolerate it, however. There is usually a good-sized difference between the air temperature and the soil temperature in the ground, while the soil temperature in a container will often get about as cold as the air, especially in times of extended cold.

From a position of complete ignorance vis a vis the OP's climate I too was wondering why the shrubs were planted in containers in the first place. It's a much more difficult and expensive way of growing than planting in the ground. What was the rationale?

'Soft Touch' hollies, like many of the lower-growing 'Helleri'-type Japanese hollies are a bit tricky anyway -- let alone growing them in pots. They appreciate good drainage yet consistent moisture, and some shade in the Mid-Atlantic.

I like the idea of putting in evergreens, but you'll need something that's hardier and you'll need to put it directly in the ground. I would consider maybe an Ilex glabra. Or consider a garden Juniper (Juniperus procumbens 'Nana'), Juniperus conferta 'Blue Pacific' or even Juniperus squamata 'Blue Star' (though they can get big over time).

They all came from Costco, except the 3rd one from the right - that is a Hoogendorn that was planted in one of my raised nursery (temporary) beds for the past 2 years and was not thriving. Honestly, I've never had luck with hollies here - in ground or above.

Frozen roots: I believe that this could definitely be the most likely culprit; that or the 5-1-1. And they may look green, but when I touch the leaves they are crunchy and pull right off. Dead. Even the Hoogendorn.

Interestingly, I also transplanted two rosemary and two Meyer lemons into the 5-1-1 last fall, which obviously have been indoors all winter, and they are doing poorly too, whereas last winter indoors they were fine (before the 5-1-1). I also have a fairy rose and two Annabelle hydrangeas ($5 deadofwinter bargains from a HD sale a few years ago that have thrived) in large pots that winter over outdoors every year and those all have buds and are alive.

The Problem ... coming in the next post.

The Problem I am Trying to Solve: covering up an ugly open area at
the base of the deck below the lattice (footings and junk under deck).
The base is gravel, not asphalt. It cannot be a raised bed and I cannot
plant in the ground due to a DEP issue. Anything planted there must be
temporary/moveable for inspections or it will count against us. So,
likewise, building a nice little wall there or something similar can't
be done either. DH won't build new lattice so forget that. Besides
lattice won't cover the ugly footings.

So... solutions.

1) Conifers - Alberta spruce is too pointy I think and won't give me the wide low coverage I need. I like the junipers. Will they survive in the pots? Do they need a special mix?

2) Try annuals in summer with fancy evergreen cuttings
a-la pinterest decorations every winter ($$$$ since I don't have a source of cuttings on the property - but I like this idea, if I were richer).

3) Not really a fan of grasses. But a deciduous shrub/plant could work if the barren parts are full enough to provide visual blockage during winter.

4) Maybe finding an aesthetic way of insulating around the pots during winter? I can't use hay/straw because we have a horrible problem with hornets/yellow jackets nesting in that - I've been stung the past two springs after using straw as a winter cover. No more straw ever.

It sounds like I'm shooting everything down, and I'm not really. I want to explore all the ideas and options. Mostly I just want to move away. But that's not happening, so I just want to not look at this ugly place every day when I drive home. Any other ideas? Thanks!

If your hardiness zone is a 6, look for something rated for a zone 4.

A container sitting on the ground is only half concerned with freezing solid. There's also a continuous freezing and thawing throughout the winter. Freezing and staying frozen, better than cycles of freezing and thawing.

realize the obvious: plants are supposed to be in the ground. Even the best suggestion is going to be just that, a suggestion. Go with hardy, or treat them as annuals.

How often are these DEP inspections, and how much warning do you get to make the area accessible? In my part of the world, we do a lot with dry-stack walls. Technically, they could be seen as temporary because they aren't mortared in place. If you preferred, a similar technique could be used with landscaping timbers.

Ilex crenata (Japanese Holly) is probably the cold hardy holly that is least tolerant of frozen roots. Even a cold deep ground frost has been reported to kill them (even if it wasn't a particularly cold winter). Not too surprising that the half barrels didn't work out.

I just looked up Ilex glabra (edited to correct - I meant glabra not crenata - from Dave's suggestion above) (Inkberry) and waaaah - now you have me wanting that.

Is there such thing as an evergreen perennial plant (not a shrub) or does that only exist if I live in Florida? Or a nice mounding perennial that has good winter interest? (I can't think of any.)

The pots are plastic, with walls about 1/2" thick so yes, I know they are pretty pathetic. I guess you get what you pay for. And now that I think about it, the mix did seem to be damp every time I thought to look at it over the winter.

I suppose I could go to Michaels and buy a bunch of plastic boxwoods and pretend they're real. ;-)

But before I stoop that low, maybe fill them all with mint? Is Candytuft actually evergreen or is that a myth? Is there a boxwood that doesn't smell like cat pee?

Maybe I should plant something different in each one and do an experiment to see what lives and what doesn't.

Please keep giving me more ideas if you have any.

Soft Touch Holly is Ilex crenata...just a named variety.

Getting any evergreen shrub to survive is going to be a challenge in the barrels. You'd have better luck with a dwarf spruce, juniper, or arborvitae than you will with a broadleaf evergreen. Even then, you'll have to manage soil moisture carefully (can't let them dry out or become bogs).

Ken, I live in CT so we are in the same climate zone. I planted 2 hollies into the ground last year. They don't look good now but I am giving them some time to see if they are alive.

I've never had luck keeping containers outside. I move everything into the garage. This might not be practical for you given the # of containers.

ctgardenguy - not practical mainly because I don't have a garage... :-(

And smivies - thanks, I meant to type Ilex glabra (Inkberry) per Dave's suggestion. Crenata was a typo.

Thanks for all the replies and info, everyone! Think I will cross post over into perennials or container garden forums for more ideas. I'm not married to the hollies - I've just always loved them.

what is a DEP issue ... i dont know the acronym .... ken

Nor did I, Ken, so I googled it. Why does the Department of Environmental Protection want to dig under someone's deck?

Twenty-some years ago, we stupidly bought a house on property in a wetlands transition area. Everything we do here is highly regulated. The DEP doesn't want to dig under my deck; just the opposite - they won't let ME dig under my deck or practically anywhere. The raised beds that I made years ago for gardening are counted as "disturbance" and count as housing square footage, even though I'm not sleeping in them. It is a big ridiculous insane regulatory nightmare. I practically need a permit to cut the grass. You think I'm kidding. The regs actually state that I can only weed with a "non-motorized manual method" i.e., by hand with scissors or something. Anyway...

Ok. I think I'd give up gardening. I'd buy a scythe and enjoy whatever wild plants chose to share the space.

We can only see a very narrow part of the space from your photo, so it is difficult to be sure what might work. How big is the gap you are trying to cover up? Would you want taller plants during the growing season along with the lower plants to cover the gap? Would a row or two of cobblestones or landscape timbers be enough to cover the gap, such as Mad_gallica suggested?

Can you set this up so that one panel is hinged and moveable for access under the deck, allowing you to plant in front of the rest of the panels in the ground? Or will that count against you as disturbance? If you plant native wetland plants that will help filter runoff is that an issue?

Can you plant things in the ground that will recover fine from being cut to the ground for inspection? How often are the inspections? For instance, spirea and Hydrangea arborescens such as 'Annabelle' can be cut to the ground and will recover within a few weeks. Neither of these are evergreen, but if that type of planting is an option, I will consider other possibilities.

If you are wedded to the idea of these planters, you might try a series of very hardy evergreen perennials and shrubs this year, and let the results next spring tell you what to plant for the final planting based on what survived. You can think about buying better insulated planters, either larger ones and lining them with a couple of layers of small bubble wrap internally and then mulching the soil surface well in autumn, or extruded foam planters, which I have seen at my local big box store. Because the foam holds air, it is light weight and provides insulation, and they resemble pottery. I find clusters of pots more interesting than only a straight line, so can you add some groupings of pots in front of these planters to break up the line? I can't see enough of the area to judge, and those groupings could have some annuals for a longer flowering period.

Check out

Geranium Biokovo

Geranium macrorrhizum

Iberis sempervirens/perennial candytuft

Vaccinium vitis-idaea/Ligonberry AKA mountain cranberry

Dianthus plumarius or D. gratianopolitanus/Cottage pinks

Sedum 'Angelina'

variegated thyme

Veronica 'Georgia Blue'

groundcover Junipers such as Blue Star

All of these survive for me in the ground, including some that are in exposed settings that freeze pretty deeply. I can't help you with info on soil mixes. I just use a mix of regular good quality potting soil and coarse compost in my containers.

Or there is always Sam_MD's solution of reasonably realistic plastic shrub for the winter and flowering annuals for the summer.

Thank you NHBabs. I love all these ideas. Insulation is probably one of the reasons my hydrangeas and rose survive in the pots. They are planted in those extruded foam concrete-look planters. I am going to try the bubble wrap interior insulation for these barrels. Does it need to be the small-cell bubble wrap? And I'll try a bunch of different plants this year to see what survives. If it's all death and gloom next spring, I'll just reconsider the whole area. Off to the nursery now to look at some plants!

And to answer, the area I'm trying to cover is about 20 inches tall from the ground. The deck is 40 ft long, but only 20 ft is exposed like this. The real problem and ugliness are these round footings that stick out. They were supposed to be covered with a stone or brick base but that never happened. Maybe someday, which is the story of my life in this house. In the meantime, I'm just hiding them with pots.

Jenswrens, I have several evergreen rhododendron and azaleas in containers in Zone 6 and they all survived this winter. I do have all the containers slightly off the ground with bricks underneath just to avoid drainage issues. I will take a look later today and give you specific names of cultivars and pictures.