new buds on rose Ducher
Buds and tender new growth (red) on the ‘Ducher’ rose.

November 20th, 2009
Freeze Warning

We Austin gardeners are living in heady times. The last two winters have been very mild. Last year I didn’t even get a killing freeze in my garden (although I know others in who Austin did). As a result, plants that usually die back to the ground–like the duranta and the Port St. Johns creeper–kept growing and flowering year around. Tender perennials that we treat as annuals–such a jalapeno pepper–demonstrated that they are indeed perennials. My aloe vera that I planted outside has survived three winters and grown and flowered. It produces so many pups and is so heat and drought tolerant that I keep planting it all over the garden. And worse, I’ve started collecting its cousins. There are 400 species of aloe and dozens of different ones are available in Austin nurseries. Some are reputed to be hardy but aloe vera is not. So far the aloe vera has reacted to the cold by turning slightly red but recovered quickly.

Aloe barbadensis
Aloe vera. I planted these in 2006. Since then they’ve doubled in size, multiplied, and flowered.

The aloe vera was only the beginning. Last winter I got tired of lugging plants I could barely carry into the house when a freeze threatened only to lug them back out again a couple of days later when temperatures returned to the 70s. So, I planted them out in the garden, too. If Austin gets several hard freezes this year will it be the end of my lemon tree, my cut leaf philodendron, two different kinds of asparagus fern, and my kalanchoe?

Kalanchoe dagriemontiana
The kalanchoe is forming new buds. These will turn to mush in a freeze.

Why do I keep buying new frost-sensitive plants like the allspice bush and the Natal plum?

As I continue planting (Austinites do most of our planting in the autumn so that our plants can have a chance to establish themselves before our deadly summer), I keep wondering if we aren’t headed for a reversal of fortune. We’ve been riding a non-freeze plant survival wave, living recklessly based on short-term memories. The forecast for this El NiƱo winter is colder than normal.

Established plants have responded to Austin’s recent rains after our two year drought as if it were spring. Several normally spring-blooming plants are flowering now and everything is putting out new growth. Even in normal years, many of our plants don’t go dormant and our ground never freezes. I often have roses in bloom at Christmas. Although on average Austin has a dozen nights of freezing temperatures, these nights are interspersed with days in the 60s, 70s, and even 80s. (If you delight in statistics, see the freeze dates at Camp Mabry between 1997 and 2006.)

Earlier this week, November 17th, the National Weather Service issued its first freeze warning for parts of our county. This should not have surprised us. The average is first freeze is December 2nd and as recently as 2005, our first freeze was also November 17th.

If the garden is unprepared and vulnerable, I think Austin gardeners are even more so. On Twitter, our responses fell into one of three camps: those who hurriedly covered plants and brought them inside, those who decided their plants were just going to have to tough it out, and those who gambled that while a freeze might hit other parts of Travis County, our micro-climate was probably safe. I was in the latter group and I won my bet with the weather. This time.

I need to get prepared. When it comes to Austin weather, anything can happen. In 1980, on the Wednesday night before Thanksgiving, it snowed.

Aloe vera

March 24th, 2008
Aloe barbadensis, aloe vera

Like fellow Austin gardener, Rachel @ In Bloom, I’ve been enjoying the spiky blossoms of aloe vera this week.

They come as quite a surprise to me. I never knew that aloe vera bloomed. For years they did nothing but form more pups. Ever since my friend Dana shared a few pups with me, I’ve kept potting and repotting them until I had three pots so heavy that it took both of us to lug them indoors each winter. I’d read they were frost-sensitive.

In the summer of 2006, however, a construction worker knocked his ladder into one of the pots. I didn’t have another large pot for the three biggest plants so I stuck them in a empty bed until I could get one. I never got around to it. The aloe survived in a dark, dry place where nothing else grew. I liked their spare geometry.

Aloe vera

So I left them. I thought winter would kill them off but as I still had plenty of pups, I didn’t mind treating these three as annuals. Winter did not kill them off. Neither did a second winter. Both winters were mild and the aloe vera have the advantage of being planted in front of a stone wall which reflects heat. Had they been elsewhere in the yard I think I would have lost them. In places, the leaves took a reddish cast from cold damage. Earlier this month they sent up bloom stalks and finally last week the yellow flowers started opening.

Aloe vera

I quickly did some Google searches on “aloe, yellow flowers” and discovered that they are aloe vera (which is their common name), Aloe barbadensis being the botanical name, although there is a trend to use aloe vera for both.

Before I dragged the pots of aloe outside this week, I cut off two of the biggest stalks and stuck them in another dark, empty spot near the front fence. The pots have gotten too heavy for me to lift and the aloe seem to prefer being in the ground.

Update: 2016-11-05

The red-flowered Aloe arborescens is said by some to be the “true” aloe, the one with the most beneficial medical properties.