Thursday, February 18, 2010

Dead or Dormant? And what do I do about it?

Dead or Dormant?

Okay. So we’ve all been watching our gardens turn to mush and sticks and crackling paper. The colors du jour are brown and black and rotten. The kind of severe freeze damage we’ve had this winter has left us wondering what will live and what will die?

Is it dormant or is it dead?

We’re on the home stretch now – we only have a few more weeks with a danger of frost left. According to the USDA Hardiness Zone map for the Austin area, our average last frost occurs between March 1 and March 31. It's typically the middle of March. I say the 15th, because I'm Type A and like my facts just so! (Mother Nature doesn't always follow my rules, though - imagine that!)

So, it’s time to think about pruning.

First, assess the damage. If you scrape along the stem of most woody perennials you will be able to tell whether it is alive or not. Scratch and look for any signs of green. Normal pruning of most of our perennials will suffice if the plant is just dormant and not dead. Many of our woody plants like Lantanas and Tecoma Stans can be pruned entirely to the ground. Just make clean sharp cuts leaving about 6” of stem above the ground. If you want to leave some size and shape on the perennial, just prune back to healthy tissue. I will do that with my large Butterfly Bushes and my giant Duranta because I want to keep some of their size.

And don’t fertilize newly-pruned shrubs. They need to use all of their energy to begin new growth and fertilizing now will over-stress. Wait until later in the spring when they are established again.

But what do we do with succulents and agaves? Many of our aloes, agaves and their cousins just bit the dust in this freeze.

Ironic, isn’t it?

Like many Central Texas gardeners, I bought a lot of these plants to expand the drought tolerance palette of my garden in last summer’s scorching heat. Then this vicious and unusually-cold winter reduced many of them to pulp!

Freeze damaged succulents are usually a lighter color, almost white, soon after the freeze. Later, that part of the plant will wilt, and then turn black with rot. In some succulents, the affected part just eventually fall off.

Even if you have rotten or dead leaves, if the bud is green and firm, the plant will likely to grow out and recover. And look closely before you start to dig -- I was shocked to find two pups under this Agave desmettiana 'variegata.' I thought it was a goner for sure, but instead of losing one, I have just now found two new plants!

However, the parts that are damaged or dead never will recover, and here is the tricky part. For these types of plants, it is important to cut out only the dead parts, whether that is a whole leaf or only a part of one. It is a risk to prune living leaves on these kinds of plants because it invites infection, and when the plants are stressed out anyway, they are more susceptible to disease.

The same applies to palm trees: if the bud is fine and you see green in the center, the plant will probably live. Cut off dead or highly damaged leaves once it is warmer. Palms grow in the warm spring and through the summer, and may look much better by the end of the summer. Just give them time.

Cacti are very sensitive to pruning timing. While they may look really bad with their dying pads and stems, it is important to wait until it is really warm to prune them. Then dust the big cuts with sulfur to help dry out the cuts. Jointed cacti regenerate really well, but the columnar ones should to be cut back to the base or you will just end up with a permanent stump. If the plant is oozing, you can give it a quiet burial.

I’m off to do my assessment and start asking all my plants…

…”Are you dead or dormant?”


LindaCTG said...

Fabulous information & congratulations on the agave pups! On base for columnar, do you mean all the way down? Thanks again!

Lisa at Greenbow said...

Yay for pups. I think I would cut back the mushy stuff but I would wait a couple more weeks. You don't want frost to get those pups.

Jayne said...

Excellent post, very informative. Congrats on the pups :-)

Pam/Digging said...

Very informative, Diana. And lucky you to find two pups under your desmettianas. I've got nothing under my two melted ones. :-(

getgrounded said...

I pulled out my desmettiana completely, Diana, after it turned to mush. Now I wonder if I had left it alone, perhaps pups would have formed. Live and learn!
And I agree, how ironic that we plant agaves to deal with drought and then they freeze.

Gail said...

Diana, It's hard to tell sometimes if things are root watching and waiting is good advice. I thoroughly enjoyed your tv interview....gail

Diana said...

LindaCTG - I was so happy to see the agave pups. Yes, all the way down the injured column. BTW - you are AWESOME!

Lisa - I will put cashmere sweaters on those pups at this point!

Jayne -- Thanks - I am so glad I didn't just start hacking at it with the shovel!

Pam - I was so surprised to see the pups since the mother plant was so new to my garden.

GetGrounded - If it was mushy and there were no pups, you were probably right to pull it.

Gail - I've even read where Sago growers left what they thought were dead trunks only to have pups come up the next season, so you never know!

MA said...

Hey, loved your part of Central Texas Gardener!!You rock, your garden rocks! So good to see you.

Diana said...

MA - Thanks! So glad you stopped by. It was really fun to do. Loving your new Wild West theme.

forest said...

That was a yearly spring chore for me as I planted agave or other plants that are borderline. Like others have said, it was best to wait for consistently warm weather before cutting out the dead stuff (even though it looks bad). Good luck!

Diana said...

forest - Next week's forcast has 36 for the low. I really hope this is the end of it. But I know the minute it start to think that I will be punished!