Protecting the garden from a Texas deep freeze — or not


We’ve just recovered from a bad case of winter here in Austin. From New Year’s Eve through Wednesday, a long deep freeze — by Central Texas standards, anyway — had us huddling by the fireplace night after night. Lows in the mid-20s rose only to around freezing during the day. Unbelievably, for the 2nd time in a month, it snowed briefly on New Year’s Eve.

As I write this, a “bomb cyclone” of snowpocalypsity is happening on the East Coast, so I don’t expect sympathy about our little taste of winter. But as I uncovered my cold-tender plants yesterday, which lay under sheets, blankets, and upturned buckets for 5 shivery days, I thought it would be helpful to share how my garden fared — the good and the bad. If you’re new to gardening in Central Texas, you may find this helpful in deciding what to protect when Old Man Winter returns. (I took these pictures yesterday; I forgot to update the 2017 watermark.)


But first, to state the obvious, you don’t have to cover anything when it freezes here except your exterior faucets. If you plant native plants and other hardy plants, they’ll handle freezing temps in stride. Covering only comes into play when you’ve pushed your luck by planting semi-hardy plants (there are so many wonderful ones!) or you want to extend the “green” season rather than letting plants die back to the roots and go dormant until next spring. Since my garden will be on a private tour next spring, I covered more plants than I normally would in order to keep them from dying back and risk not having them fully regrow by early May.

Also, covering helps but isn’t foolproof, and other factors matter too: whether a plant is near a heat-holding surface like a brick wall or stone patio; whether it’s in the ground (insulated) or in a pot (vulnerable to cold); whether it’s cold and wet (deadly for tender succulents) or just cold; and whether your garden enjoys a warmer or colder location (hilltops and in-town are warmer; low spots and away from the city are colder). Blankets and sheets should be anchored so they don’t flap around when the cold front blows in and should cover the plant completely to hold the soil’s warmth. You can also use overturned trash bins and buckets to protect plants.

During our cold snap, I noticed that some people make a big effort to cover plants that don’t need protection, like yuccas. So accompanying my pics of my own post-freeze plants, here are my recommendations about protecting plants from hard freezes. Again, this is just for the Austin area, and your mileage may vary.


Yuccas, sotols, and nolinas are generally winter tough. Don’t waste your time covering these. Pictured here is paleleaf yucca (Yucca pallida), a native plant and totally winter hardy.


Yucca rostrata is also a winter stalwart. Don’t bother wrapping it up like a lollipop.


Agaves are trickier. Some are winter hardy, like ‘Green Goblet’ pictured here (its winter cage is to protect it from deer antlering), some may survive with damage, and some are not freeze hardy. Know your agaves, and protect those that need it. I grow a few small, non-hardy agaves in pots so that I can bring them inside during freezes. Big ones in the landscape need to be hardy: whale’s tongue, ‘Quadricolor’, squid agave, artichoke agave, A. lophantha, artichoke agave, ferox agave, etc. American agave, the big blue or yellow-and-green-striped variety, is commonly found in Austin too, though it’s only semi-hardy; it usually survives periods of deep cold but with some damage.


Whale’s tongue agave (Agave ovatifolia), at left, is winter hardy. But do make sure it and other dry-loving plants like yuccas have excellent drainage when you plant them. Even cold-hardy succulents can rot in winter if they’re parked in damp soil.

Sotols, like the toothless sotol (Dasylirion longissimum) in the steel pipe planter, are hardy. So are hesperaloes like giant hesperaloe (Hesperaloe funifera) and red yucca (Hesperaloe parviflora), pictured at back in the red planter.


Texas sotol (Dasylirion texana) is totally hardy.


Dyckias are a bit iffier. I grow only those dyckias that I’ve found to be tolerant of occasional temps in the 20s, like ‘Frazzle Dazzle’ and ‘Burgundy Ice’, pictured here, and I cover them during hard freezes just to be safe.


Yuccas are tough enough for our summers and winters. Some, like ‘Bright Edge’ yucca, have colors that intensify in cold weather.


‘Color Guard’ yucca takes winter in stride too. But notice the bamboo muhly grass (Muhlenbergia dumosa) behind it — sad and straw-like after temps in the 20s. It’ll live but will take months to recover. Don’t cut back the bleached foliage until well into spring. Some stems will sprout new green leaves in spring, and until then it helps protect the roots.


How about mangaves, agave-like succulents that are a cross between agave and manfreda? They can be harmed by a strong cold snap, so protect them. This is ‘Espresso’ mangave, a variegated version of ‘Macho Mocha’. I covered it, plus it’s planted against a heat-holding wall and under a tree, and it came through in good shape. It may lose one leaf, which feels kind of soft and mushy, but I’ll have to wait and see.

The squid agave beside it is totally fine.


Here’s ‘Macho Mocha’ mangave, which I covered by draping a sheet over a bamboo pole stuck in the ground, which keeps the fragile leaves from breaking if there’s ice. It looks to be in good shape. The ‘Quadricolor’ agave in the pot and the whale’s tongue agave are fine too, with no protection.


Aloes, like dyckias, can be dicey in a deep freeze. I covered three big soap aloes (Aloe maculata) growing in a raised bed against the back of the house, and the two that were closest to the house look good, with intensified coloring from the cold, while the third (at left) is soft: when I pinch the leaves, they feel a bit mushy instead of firm. That’s not a good sign, and I’ll probably lose that one. In any case, I’ll wait until spring to remove it, as its damaged leaves will continue to protect the roots and any pups (baby aloes) that can be replanted to replace it.


‘Blue Elf’ aloe, in the foreground, needs protection from hard freezes too, especially later in winter, when it starts sending up bloom spikes. The variegated squid agave ‘Monterrey Frost’ behind it would probably be fine without protection, but I adore this plant and covered it just to be sure. Ice might break its fragile, arching leaves, so I put stakes in the ground next to it and draped a sheet over those.


Cactus is variable, even among the prickly pear family. Opuntia ‘Ellisiana’ (not pictured) can handle the cold. Opuntia ‘Old Mexico’, pictured here, can too, although it tends to flop over in dismay. It should recover quickly when spring returns, and I’ll cut off any pads that stay flopped. Those can be replanted or given away.

Golden barrel cactus should be protected from hard freezes, and I keep mine in a pot and bring it indoors. Plenty of Austinites plant them in the ground though, and most of the time they survive, although you can lose them if it’s cold and wet. Other hardy varieties include horse crippler and lace cactus.


Gopher plant (Euphorbia rigida), at right, will survive with no protection, although it may flop in protest. Native grasses like pine muhly and Mexican feathergrass (lower left) need no fussing whatsoever.


Bamboo muhly, however, gets bleached out in the 20s. I don’t cover it because it’s big and I have so much of it. It’ll survive but will take months to recover. See my comments above about when to prune it.


‘Vertigo’ pennisetum grass is bleached, but it’ll survive. I leave the dead leaves so they can protect the roots and then prune the whole thing to the ground in late February or early March. (It usually benefits from a division then too; dig it up, saw the root ball in half, and replant half. Plant the other half somewhere else or give it away.)


As for palms, I’m familiar with only two kinds, and both are winter hardy: Mediterranean fan palm, pictured here…


…and our native dwarf palmetto (Sabal minor), pictured in the foundation bed. No need to cover either.


I’m trialing from Southern Living Plants three ‘Platinum Beauty’ lomandra, grass-like plants native to Australia. One is in a pot, and the other two are in the ground. I covered all three, and they seem to be doing fine.


Abutilon takes deep cold with mixed results, in my experience. Abutilon palmeri, aka Indian mallow, should be considered an annual here; a hard freeze will kill it. This is ‘Bartley Schwarz’, and it does fine with no protection. Other varieties I grow that I consider marginally hardy include an unnamed pink one from Barton Springs Nursery, variegated ‘Souvenir de Bonn’, and ‘Nabob’. I don’t cover any of them — it’s survival of the fittest. The nice thing is they’ll often bloom even in winter.


One plant I depend on in my dry-shade, deer-infested garden is variegated flax lily, or dianella (Dianella tasmanica ‘Variegata’). It doesn’t like 20-degree weather any better than most Austinites, turning straw like and dying back to the roots — or maybe altogether. I covered as much of it as I could, but this clump was unprotected, with typical results. The shriveled appearance will only worsen in coming days, I expect.


I tucked heavy blankets across two swaths of dianella in the front garden, and they look like they just enjoyed a holiday in the Caribbean. The same with this one, which I covered with a pot in the back garden.


Foxtail fern (Asparagus meyeri) is another exotic that I rely on for success in dry shade and with deer. It also hates the cold and can be bleached or even killed by severe freezes. I covered as many as I could but missed these two. They suffered frost burn but should recover.


I threw a sheet over these, and they look like they just got home from that Caribbean cruise too. Good as new!


Firecracker fern (Russelia equisetiformis) hates cold and goes dormant but returns in spring. It sure looks sad for now, though.


I protected a firecracker fern I’m growing in a pot on the porch, and it made a big difference.


Mexican honeysuckle (Justicia spicigera) is so pretty all winter if we don’t get temps in the 20s. So much for that! Like last year, it’ll die to the ground but will return in spring. I’ll leave it standing, along with all my freeze-dried perennials, until around Valentine’s Day, when I do the big pre-spring cut-back.


Same with Philippine violet (Barleria cristata) — no protection, and it died back but will return. Notice the evergreen Texas sotol, a native beauty, looking like What winter? beside it.


Purple oxalis (Oxalis triangularis) is small enough that it would be easy to cover, if you’re so inclined. I didn’t, it died back, and it’ll come back in spring.


Purple heart dies back messily, but you cannot kill this plant for good. It’ll be back in early spring. The ‘Scott’s Turf’ sedge needs a haircut to neaten it up. I’ll give it one with a trimmer in early spring.


Pond plants can be vulnerable too. When a hard freeze is predicted, I drop the dwarf papyrus and the burgundy crinum to the bottom of the pond and just leave them there until it warms up. The pond was iced over for days (see picture at the top of this post), but no matter. They stayed snug and warm(ish) at the bottom of the pond. I don’t worry about the hardy water lilies. They usually die back partly or all the way, and they’ll come back in spring. See my post about winterizing a stock-tank pond for more info.


Ferns like our native river fern (Thelypteris kunthii) will die back, but they’ll come back in spring. I added this native wavy scaly cloakfern (Astrolepis sinuata) to my garden last fall, and it didn’t make the cover-up list. For now, it looks pretty sad, but alive.


One plant that continues to impress me with its performance, no matter the weather, is ‘Sparkler’ sedge. It’s wonderful for shade, even dry shade, and handles heat and cold with ease, even in a pot. No protection is needed, aside from shade from the Death Star.


Succulents in my cinderblock wall always get covered by a sheet when there’s a freeze, and with the reflected heat from the patio and a live oak overhead, they generally fare quite well. It helps that I’ve winnowed them down to the hardiest varieties over the years, like ghost plant (Graptopetalum paraguayense), various sedums (‘Coppertone’, ‘Blue Spruce’, ‘Dragon’s Blood’), and an occasional echeveria (although these have more trouble with our summers, I’ve found). If any don’t survive, they’re easy to replace in spring.


My most cold-tender succulents are grown in pots, and I bring them indoors…


…or into the garage during hard freezes. Stuffing them cheek by jowl into two wagons helps with moving them in and out throughout the winter. Lucky gardeners who have greenhouses for such plants!


It’s a lot of work to cover plants for a hard freeze, and I don’t recommend getting sucked too deeply into it. Plant mostly hardy plants unless you’re a rabid collector who doesn’t mind pampering her babies, or make peace with the occasional winter’s reaping. When hardy perennials get freeze-dried, leave them standing until mid- to late February so they can shelter the creatures who share your garden, as well as their own roots, and so their seeds can provide food for birds. It’s only another month and a half, and then you can whack them back to your heart’s content.


After all, spring will be showing its first green signs by late February and early March.

I welcome your comments; please scroll to the end of this post to leave one. If you’re reading this in a subscription email, click here to visit Digging and find the comment box at the end of each post.
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Digging Deeper: News and Upcoming Events

Calling all garden bloggers! You’re invited to register for the annual Garden Bloggers Fling tour and meetup, which will be held in Austin this May 3rd-6th! Click this link for information about registering, and you can see our itinerary here. Space is limited, so don’t delay. The 2018 Fling will be the event’s 10th anniversary, which started in Austin in 2008.

Join the mailing list for Garden Spark Talks! Inspired by the idea of house concerts, I’m hosting a series of garden talks by inspiring designers and authors out of my home. Talks are limited-attendance events and generally sell out within just a few days, so join the Garden Spark email list for early notifications. Simply click this link and ask to be added.

All material © 2006-2018 by Pam Penick for Digging. Unauthorized reproduction prohibited.

How to prune clumping bamboo


I’ve known many people who are afraid to plant any kind of bamboo, even a clumping type, for fear it will take over their yard — and with good reason. Here in Austin, many a back yard is clogged with running bamboo, which is often planted for privacy along a fence but quickly metastasizes, spreading across the lawn and into the neighbors’ yards as well.

Clumping bamboos, however, don’t “run,” making them garden-safe.* Even so, they grow vigorously enough to require regular pruning in order to look their best. Take ‘Alphonse Karr’ bamboo, for example (pictured here). I usually prune it twice a year, in late spring and early fall, to keep it from looking like a shaggy green beast and to give it shapely definition. Here it is in beast mode (above) — lots of leaves amid a thicket of culms (the canes) that are arching over the gutters and blocking a window.


And here it is after an admittedly exuberant pruning. I removed about a quarter of the culms entirely, all the way to the ground (never cut them off halfway, which causes ugly side growth), and limbed up others, revealing the green-and-yellow stripes on the exposed canes.


I start by trimming off the side branches that grow along the culms, starting at ground level and pruning up to just above my head. How high up you prune should depend on the height of the bamboo. You do still want to have plenty of leaves up top to keep the plant healthy.


Using a pair of sharp bypass pruners, clip off the stems close to the culm, holding onto them with your free hand to keep from making a mess below. Just toss them in a bin for composting later. And be careful not to nick your free hand with the pruners!


I use a long-handled pruner for getting into the culms and pruning out weak ones or those leaning over the gutter. I also thin out culms that spread beyond the original planting.


And that’s it. It’s a pretty Zen activity, really. Here’s another look at the overgrown beast, before pruning. Nothing wrong with this, of course, if you need a green screen that won’t run, but it’s too much for a small space like this one.


And here it is after an hour of pruning. Leggy, airy, and out of the gutter!

Here are a few more bamboo-pruning resources:

I first learned about limbing up bamboo on the Austin blog Growing Optimism, which also features a nifty bamboo-and-zip-tie fence to hold leaning canes away from paths: Growing bamboo in a narrow space – pros, cons, and a solution for support

For expert advice, watch Cass Turnbull of Plant Amnesty explain how to prune bamboo: How to Prune Bamboo – Instructional Video w/ Plant Amnesty

Also, watch Austin’s own Merrideth Jiles share his extensive knowledge of bamboo, including pruning tips, on Central Texas Gardener: Bamboo Basics | Merredith Jiles |Central Texas Gardener

And finally, here’s a helpful list of clumping bamboos for Austin from The Great Outdoors nursery. By the way, although TGO’s guide says bamboo needs to be watered twice a week during Austin’s summers, I have not found this to be true in my garden. Once a week works fine for my established bamboos ‘Alphonse Karr’, ‘Tiny Fern’, and, to a lesser extent, Mexican weeping bamboo.

*Note: Clumpers do gradually expand but not aggressively. Please, do your research to learn which is which before buying. I can’t think of any reason to plant a runner, frankly.

I welcome your comments; please scroll to the end of this post to leave one. If you’re reading this in a subscription email, click here to visit Digging and find the comment box at the end of each post.
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Digging Deeper: News and Upcoming Events

Mark your calendar for the Inside Austin Gardens Tour on May 6, sponsored by Travis County Master Gardeners. This fun garden tour occurs every 18 months and features a mix of homegrown gardens “for gardeners, by gardeners,” as their tagline says.

Get on the mailing list for Garden Spark Talks. Inspired by the idea of house concerts — performances in private homes, which support musicians and give a small audience an up-close and personal musical experience — I’m hosting a series of garden talks by design speakers out of my home. Talks are limited-attendance events and generally sell out within just a few days, so join the Garden Spark email list for early notifications. Simply click this link and ask to be added.

New galvanized wall planters hold succulent cuttings


Spring fever has hit! For me, that manifests as refreshing my many pots of succulents, some of which have been inside all winter, others huddled against the house, and others (too big to move) left to weather as they will. If they took a winter hit, I’m not afraid to rip them out and start over. After all, succulents last a long growing season here in Austin, and it’s worth it to buy a few new 4-inch pots each spring to freshen up winter-weary containers.

Even more fun, I’ve been creating new containers with cuttings from winter-hardy succulents that needed a trim, tucking in a few new plants and decorative accents. Kitschy, fairy-garden flamingos stalking through a succulent jungle? Heck, yeah!


But let’s start with the planter. I found three galvanized wall planters at Target a couple of weeks ago, lying forlornly on a back-corner shelf before all the other spring garden stuff came out for display. I’d seen these online and coveted them, but they weren’t available for shipping, and Target’s website indicated there were only a few left in stock at various stores. So I wasn’t expecting to find them, but then I did! At only $8.99 each, I snapped up all three. (And no, I’m not getting paid to promote these. I just like them.) They look like deep-dish pizza pans to me.


The pots didn’t have drainage holes, so I used a hammer and nail to punch a few holes in the bottom of each one. Then I filled them up with cactus/succulent potting soil (you can buy it by the bag at most nurseries), tucked in a few cuttings from my succulents (let them harden off a few days after you cut them, before planting, to avoid rot), topped them with a thin layer of small gravel, and voila! So. Easy.


The copper-and-glass sun and the flamingos came from The Natural Gardener‘s gift shop. Anything can work for an artful or playful accent, though. Maybe a plastic dinosaur? A small Buddha figurine? A vertical piece of driftwood?


Succulents can easily be pulled out and refreshed with new cuttings when they grow too big or get leggy. In our hot climate, be sure to place them in dappled shade or morning sun only. Afternoon sun can fry them.


Here’s where I hung them, over my new galvanized potting bench, also from Target, which I assembled and placed in my side yard. After years of potting over a low table, I’m loving having this taller potting station, and my back is thanking me too. I’ve stashed potting supplies in a couple of galvanized pails with lids, and I’ll be rotating plants and pots through here all spring.

In fact, I’m going outside right now to do a few more pot refreshers. Spring feverrrrrr!

I welcome your comments; please scroll to the end of this post to leave one. If you’re reading this in a subscription email, click here to visit Digging and find the comment box at the end of each post.
_______________________

Digging Deeper: News and Upcoming Events

Get on the mailing list for Garden Spark Talks. Inspired by the idea of house concerts — performances in private homes, which support musicians and give a small audience an up-close and personal musical experience — I’m hosting a series of garden talks by design speakers out of my home. The upcoming talk with James deGrey David has sold out, but join the Garden Spark email list for speaker announcements delivered to your inbox; simply click this link and ask to be added. Subscribers get advance notification when tickets go on sale for these limited-attendance events.

All material © 2006-2017 by Pam Penick for Digging. Unauthorized reproduction prohibited.

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