Cold Protection

ScotTi

Esteemed Member
4,828
16/04/08
312
163
With the pending week with nights at or near freezing I will need to cover the inground Crotons. I will be covering them today. Problem is, with a work week coming I will not be able to uncover untill next Saturday. Will the Crotons be ok with a week in the dark? Or will I come out better taking my chances and not cover?
 
Thanks for posting the link - if I understand it, most of the lights/covers etc don't really help much.....

And I am not surprised one bit. Last time we had forecast frost - which didn't materialize here - I covered stuff with frostcloth.... and it didn't help - in fact, everything covered with it had browned areas, and similar plants left uncovered were fine.

My special crotons are kept in pots, and we hauled them all in last night, since losing some crotons last year to cold-stress. They'll be spending most of this week indoors. Here's the photo of crotons filling a room (photo x-posted to IPS Weather forum)
 

Attachments

  • 1_2_10 Keeping them warm2.jpg
    1_2_10 Keeping them warm2.jpg
    146.8 KB · Views: 227
With the pending week with nights at or near freezing I will need to cover the inground Crotons. I will be covering them today. Problem is, with a work week coming I will not be able to uncover untill next Saturday. Will the Crotons be ok with a week in the dark? Or will I come out better taking my chances and not cover?

Hi Scott - I would hesitate to keep the crotons covered for that long. it could do more harm than good. Crotons need good air flow or they suffer and drop leaves.

One thing that I have found very helpful with sensitive shrubs is to pile mulch - esp. pine straw or oak leaves - around the base of the plants before a freeze. The earlier in the day, the better. The mulch absorbs the heat from the sun (what little there is!) and keeps the soil temps around the plant warmer through the night. Immediately after the cold event, rake the stuff away from the trunks so they won't get a fungus. (btw I didn't do this last year, or any other cold protection. I lost some crotons in pots that I failed to bring in - won't happen again.)

I hope this helps. I've had some good results doing this.
 
I absolutely agree with Sihara.....

I have been living in South Florida over 50 years . We gave up on lights , sheets and frost blankets a long time ago.

We went to our local feed store on Saturday and bought 3 bails of cheap pangola hay. It is amazing the heat this stuff throws off.

In fact, I must be careful not to cover my dormant aroids or they will suddenly wake up months before they should. After the first threat of frost, we rake it up into a ring around the plants ready for the next cold snap. It can really reduced the amount of trimming in mid March.

God I hate cold weather :)
 
Cold protection is a fascinating topic, but does anyone know of any scientific studies based on field trials with a large population sample for any tropical plant? aroids, crotons, palms, cycads, pick your favorite....
...and what do we mean by cold protection? Are we trying to prevent the plant from defoliating, turning to mush, or survival with some damage.

..and what kind of cold? is there a threat of frost? Some plants will tolerate freezing or below but will not tolerate frost (some cycads come to mind here). How windy will it be?
What is the relative humdity (other than too low)? Although plants do not feel 'wind chill' the way we do, drying and desicating winds can cause a lot of damage in addition to the cold temperatures.

..and let's not forget we are dealing with a genetically unstable plant here. A few of my crotons (Queen Victoria and Interuptum) defoliate quite easily while crotons right next to them survive untouched. Sometimes one Interuptum will defoliate and the other will not. So here's what I do based on the severity of the cold snap.

For any cold snap, water well ahead of time. Wet or damp soil retains more heat than dry soil.(The specific heat of mud is higher than that of dry dirt). I figure the plant also has some moisture available to it to prevent gross transpiration losses in leaves due to low relative humidty and drying winds. Never water if the water will freeze. Check those irrigation timers.

For temps forecast to stay at or above 32F, I may move a few primo plants into the house or garage. Everything else is on its own.

For temps below 32F and low to no wind but a threat of frost, I'll cover the frost sensitive plants if they are not under a canopy.

For temps below 32F and high winds, no threat of frost so no need to cover to prevent frost burn. Covering almost anything is futile since the cold air works its way in all too quickly and covers blow off unless securely anchored.

For something like the 12/1989 freeze, get the chain saw ready.

If a croton gets badly toasted, I wait at least two weeks or more before doing any pruning of damaged branches, and usually longer since we may get another shot of cold air depending on how early or late in the winter. Almost all crotons will recover if lowest one foot and the roots are not damaged. (Think of roses up north). My not-too- bright neighbors chopped some crotons down to ground level to replace some windows; six months later, they were at least two feet tall and healthy looking.

Fortunately, the low this a.m. here in south St. Pete was 38F.
 
Thanks for all the info. I made a large tent out of freeze cloth and covered the plants that have no to little canopy overhead. The crotons with overhead canopy are on their own. I just expect to keep frost off of the plants, but after 2 frost/freeze threats the last 2 mornings, so good. The temp. this morning is at 41F with some wind. Hope the luck holds.
 
Good points Phil!

One thing to add is the crotons are hardened off now. The chance of significant damage is less likely than if this type of cold had hit in early December after 9 months of 80+ degree weather.

I have found that any type of cover helps retain some heat. A small sheet/comforter or frost cloth provides the similar benefit a large overhead tree does. If temps are forecast to be at or a couple of degrees below freezing, the sheet or cloth can make all the difference. With an advective freeze, any type of cloth has to be anchored down.

Groups of crotons (even potted ones) grouped close together are also less likely to suffer damage.
 
I have kept the frost cloth tent over them for a week now and have a few more days to leave it on. Right now I have sleet & snow mixed in with rain and its 35f. The real test for these Crotons will come in the next 2 days with lows temps in 25f- 29f range.
 
...and here's what happen when one does not take basic precautions. Everything made it through the past week+ cold snap just fine until the early AM today - 35F and moderate frost. These are about the only crotons in the yard that are not under any canopy and consequently are the only ones that got whacked by the frost. Note how most vertical leaves did not get frosted and how the new growth protected the older leaves under some.
I'll wait at least a month before pruning and expect them to make a full recovery - if we don't get any more &^%$#@! cold wx this year.

1. mushy Diane
2. Gen Paget - leaves under are OK
3. Cornbread in foreground - OK due to a dab of canopy; Kentucky is mush
4. L to R: Mini fishbone, OK; "ugly in great color" is mush; Diane - mush

A little prevention like an old bed sheet would have prevented this.
 

Attachments

  • DSCN2380.jpg
    DSCN2380.jpg
    346.5 KB · Views: 219
  • DSCN2382.jpg
    DSCN2382.jpg
    265.6 KB · Views: 200
  • DSCN2383.jpg
    DSCN2383.jpg
    316.3 KB · Views: 213
  • DSCN2384.jpg
    DSCN2384.jpg
    297.6 KB · Views: 212
My report:

Geisha Girl - not happy
Veitchia - not happy
Charles Rutherford - not happy
Kentuck - not happy
Dreadlocks - not happy
Gloriosa - not happy
Royal Flush - not happy
Frank Brown - not happy
Tortoise Shell - not happy

further cold damage later :(
 
Ron, that's downright amazing given where you are. If there was one place in this state - other than the keys - that seemed safe from the cold, that would be it.

My collection of favorite crotons - getting to be a long list - is all in pots and was indoors for a week, joined by cordies, palms & a few other favorites. Consequently, the indoor-crotons' colors are far better than those planted outside.

Of those in the ground:

Gold Dust under D. lute canopy - fine
AFD5s - okay so far (except for 1 recent transplant)
Gloriosa - okay so far
Yellow unknown that resembles Fishbone (but Ray says it isn't) - decent
Mammies - glum but alive
Queen Victoria planted by the Gloriosa - fairly wilted but alive.
Rudy Bachman in large pot under canopy - fairly wilted but alive
Nestor - trashed
Norma - trashed (recent transplant)
FDR & Eleanor - trashed (recent transplant)
AFD-Unknown - trashed
Stoplight - trashed
Another yellow one similar to Fishbone - trashed (recent transplant)
Rainbow - trashed

Little damage occurred prior to Tuesday morning's appalling frost.

Moral: 1) Canopy is everything. 2) Don't transplant in winter - and I must've been a dumb@$$ to do that!
 
Top