Wednesday, April 23, 2014

So What's the Damage?

Alchemilla mollis, Lady's Mantle, unhurt by a late freeze, looking bigger and better than ever this year.
Alchemilla mollis, Lady's Mantle, unhurt by a late freeze, looking bigger and better than ever this year.


The Details:

The weekend of April 12th, temperatures topped out near 80 degrees (Fahrenheit). Then a cold front came crashing through - two nights in the mid-30s and one night where temperatures dipped all the way to 28 degrees Fahrenheit in our neighborhood. (I foreshadowed this cold snap in a blog post last week.)

In true Darwinian style, I left most plants uncovered and unprotected to fend for themselves.

Remarkably and encouragingly, most pulled through without any problems. Here's a list of the ones that laughed off the cold and the few where winter got the last laugh.


Little or No Damage:

- Agastache foeniculum, Golden Jubilee
- Ajuga genevensis (leaves and flowers both unharmed)
- Alchemilla mollis
- Aronia, Chokeberry (buds, flowers and leaves all unharmed)
- Athyrium nipponicum, Japanese Painted Fern (newly planted)
- Baptisia australis (covered with an overturned pot for protection)
- Cercis canadensis, Redbud (flowers and emerging foliage both appear unharmed)
- Chrysogonum virginianum, Green and Gold

Chrysogonum virginianum, Green and Gold, undamaged by the cold, now bursting into bloom.
Chrysogonum virginianum, Green and Gold, undamaged by the cold, now bursting into bloom.

- Clematis "Crystal Fountain" (leaves and buds both appear unharmed)
- Cranesbill Geraniums (Biokovo, Rozanne and sanguineum)
- Dianthus gratianopolitanus "Firewitch"
- Echinacea purpurea
- Fothergilla gardenii (leaves appear unharmed, some flowers may have been damaged, others seem to be fine)
- Gaillardia x grandiflora "Arizona Apricot"
- Helianthus "Lemon Queen" perennial sunflower
- Hemerocallis, Daylilies
- Hydrangea quercifolia, Oakleaf Hydrangea

Hydrangea quercifolia, Oakleaf Hydrangea, seemed unfazed by the cold. I planted this shrub in autumn 2012 and did not see any flowers last year. Maybe this is the beginning of a flower panicle?!
Hydrangea quercifolia, Oakleaf Hydrangea, seemed unfazed by the cold. I planted this shrub in autumn 2012 and did not see any flowers last year. Maybe this is the beginning of a flower panicle?!


- Hypericum frondosum "Sunburst"
- Juniperus virginiana, Brodie, Burkii and Grey Owl varieties
- Lavandula, Lavender, "Hidcote" (newly planted)
- Liatris spicata
- Liriope muscari (newly planted)
- Lonicera sempervirens, Coral Honeysuckle (leaves, buds and flowers)
- Malus, Crabapple, "SugarTyme" variety (leaves seem fine, flowers were pretty much finished blooming anyway, so it's hard to gauge whether they would have been damaged)
- Panicum virgatum, Switchgrass, "Northwind" (covered one clump with an overturned pot, but new growth on both protected and unprotected clumps seems equally unharmed)
- Philadelphus x virginalis, Mock Orange, "Natchez" (leaves and buds both seem unharmed)

Philadelphus x virginalis, Mock Orange, Natchez variety, leaves and buds appear totally undamaged by last week's cold snap
Philadelphus x virginalis, Mock Orange, Natchez variety, leaves and buds appear totally undamaged by last week's cold snap

- Phlox paniculata
- Platycodon, Balloon Flower (covered one clump with an overturned pot, but the control clump that was not covered looks fine too)
- Polystichum acrostichoides, Christmas Fern (newly planted)
- Rhus aromatica, Fragrant Sumac, "Gro-Low" (buds seem fine, there may be a little foliar damage on some emerging leaves, but I think the majority of emerging foliage seems fine at this point)

Rhus aromatic "Gro-Low" Sumac does not seem to have been set back at all by the freeze
Rhus aromatic "Gro-Low" Sumac does not seem to have been set back at all by the freeze. Check out those beautiful lemon yellow buds and fresh multicolored foliage! I'm enraptured!!

- Stachys byzantina, Lamb's Ear, "Helene von Stein"
- Veronica umbrosa, Prostrate Speedwell, "Georgia Blue" (leaves and flowers both seem unharmed)
- Viburnum prunifolium, Blackhaw (buds and open flowers both seem unharmed)
- Viburnum x pragense, Prague (buds and open flowers both seem unharmed)

Neither the new leaves nor the flowers on the Prague Viburnums were damaged by the late freeze
Neither the new leaves nor the flowers on the Prague Viburnums were damaged by the late freeze

- Viburnum rhytidophylloides, Alleghany variety (perhaps a little foliage damage on some plants, another seems unharmed)



Moderate damage:

- Agastache rugosa, Honey Bee Blue (perhaps 30% of foliage seems damaged/killed on newly installed plants)
- Aucuba japonica (established leaves seem fine, some of the of emerging new growth may have been damaged)
- Buxus sempervirens, Hardy Boxwood (established leaves seem fine, but new growth seems limp and damaged, I suspect I'll need to break out the pruning shears and give the Boxwoods a haircut back to healthy growth)

Wilted and whitened foliage marks frost and/or freeze damage on a Boxwood (Buxus)
Wilted and whitened foliage marks frost and/or freeze damage on a Boxwood (Buxus)


- Cephalotaxus harringtonia, Japanese Plum Yew, "Prostrata" (established foliage seems fine, it looks as though the new growth may have been damaged, but I'm not familiar enough with this newly-installed plant to diagnose the degree of damage with any certainty)


Major damage:

- Ceratostigma plumbaginoides, Leadwort Blue Plumbago (newly emerging foliage seems limp, dark brown and dead)
- Hibiscus syriacus, Rose of Sharon (newly emerging foliage and young leaves on both Rose of Sharons looks limp and dead)

Newly emerging foliage got fried on this Blue Bird Rose of Sharon.  This photo was taken about a week after the cold snap.
Newly emerging foliage got fried on this Blue Bird Rose of Sharon.
This photo was taken about a week after the cold snap. 


- Lagerstroemia indica, Crape Myrtle (most newly emerging foliage looks dead and blackened, fortunately several trees had not yet started to leaf out, interestingly foliage on a few branches of one Natchez crape seems fine, even though foliage on other branches seems dead!)

Luckily not much foliage had emerged before the cold snap on the crape myrtles, which are some of the latest trees here to leaf out. The leaves on this branch that had started emerging seem to be toast. All the green leaves in the background were still dormant buds during the freeze and have just awakened and put out green foliage in the past few days.
Crape myrtle with frozen dead leaves and fresh green leaves on different branches

- Vitex agnus-castus, Chaste Tree (newly emerging foliage appears to have been totally killed)

Vitex agnus-castus foliage appears to have bitten the dust.
No sign of any new foliage yet in the week since the freeze.


So that's the story.

Overall, I was very pleased with the way most plants pulled through.