Ask Me Help Desk - Salvia Leucantha & Nandina Domestica Dying

Hi All,
First let me start by saying I am not much of a gardener... I currently have a few plants that are not looking so great, and I'm not sure what went wrong, or if there's anything I can do. I am located in Tucson AZ.

Everything is on a drip system. It waters on odd numbered days for 2.5 hours. Everything was lightly pruned 2/2009 and an "amaze" type pre-emergent was used. I lightly fertilized with "arizonas best" in 7/2009.

I have 4 salvia leucantha (mexican bush sage) in a corner that get full sunlight. They looked great when they were planted a year ago, but this year 1-2 started looking dry/dead'ish, and then finally 1 completely died. The second looks bad, and the other 2 are alive and blooming, but much smaller than they used to be. Not sure if its over/under watering, bugs, disease, etc. The first one to die is lighted at night via a low voltage light - not sure if that attracted bugs or not. There are two drip lines running to each salvia. Not sure if they are 1GPH each or more. Links to pictures below:

Salvia when first planted: http://i232.photobucket.com/albums/e...4/CIMG2254.jpg

Salvia prior to pruning (only removed long stalks): http://i232.photobucket.com/albums/e...4/CIMG2962.jpg

Salvia last month: http://i232.photobucket.com/albums/e...4/CIMG3330.jpg

http://i232.photobucket.com/albums/e...4/CIMG3333.jpg

One dead (dug it up today): http://i232.photobucket.com/albums/e...4/CIMG3426.jpg

Others blooming, but don't look as big and happy: http://i232.photobucket.com/albums/e...4/CIMG3425.jpg

Any thoughts? It doesn't look like bugs. Did I over-water? Did I stress them out with the fertilizer/pre-emergent?

I think I'm going to re-plant. Should I do it now, or is there a better time of year?

Thanks!

HI! Bugman-74, welcome to AMHD :)

Quote:

It doesn't look like bugs. Did I over-water? Did I stress them out with the fertilizer/pre-emergent?

I agree, it doesn't look like bugs, and I don't think you stressed them... well, maybe, in one area. Those salvia's only need to be watered once a week to every other week,
Salvia leucantha
They like damp, not moist or wet waterings, here in the Fall, and the soil has to be on the loamy side wikipedia-Loam

How's the soil they're in? It look's like it might be compacted.

http://i232.photobucket.com/albums/e...4/CIMG3330.jpg

Are the planting holes at least as large as the diameter of the plants in the pix?

Pull back the stone mulch you have, and enlarge their homes.

As for a replant... If they look like the one in the corner,

http://i232.photobucket.com/albums/e...4/CIMG3426.jpg
I'd say yes. Swap those out,

But the ones that still have some green, stop watering them, cut them back to 'bout as tall as in this pix.

http://i232.photobucket.com/albums/e...4/CIMG2962.jpg

'bout the replant. If your minimum temps don't fall below 50°F ~ 10°C I think you'll be okay.

Edit, added info.

Had to leave for a while, didn't forget the Nandina domestica...

PlantFiles: Detailed information on Heavenly Bamboo, Nandina Nandina domestica

Missouri Botanical Garden - Nandina domestica

While the salvia's water requirements are minimal, the heavenly bamboo, needs more frequent waterings, but are you really sure you want to cultivate this plant?

sacred bamboo: Nandina domestica (Ranunculales: Berberidaceae): Invasive Plant Atlas of the United States

How long have you had it? I ask because it may take a year for new shoots to show up, so don't throw it away until at least another growing season has gone by.

There's an old sayin'...
The first year it sleeps
The second year it creeps
The third year it leaps.

K

Quote:

How's the soil they're in? It look's like it might be compacted.

Are the planting holes at least as large as the diameter of the plants in the pix?

Thanks for the reply! I will try to cut back watering the salvias... Unfortunately I only have one circuit on the drip system. There are currently two drip lines to each salvia, so I could probably plug one, and reduce the other to a lower GPH emitter, if you think that would work?

This is what it looked like when they were planted (no idea of the holes were enlarged, or if any special soil was used). Best way to describe the dirt around here is "desert." Its very hard, compacted, and dry.

http://i232.photobucket.com/albums/e...4/CIMG2233.jpg

http://i232.photobucket.com/albums/e...4/CIMG2234.jpg

Our winter low's only drop into the 40's at worst. Perhaps I should wait until February or so to replant the dead one.

Quote:

but the ones that still have some green, stop watering them, cut them back to 'bout as tall as in this pix.

You mean cut them all the way back to where the geen shows in that picture (almost to the ground)? Should I do this now, or wait until Nov/Dec/Jan?

Thanks for the help!

Quote:

... the heavenly bamboo, needs more frequent waterings, but are you really sure you want to cultivate this plant?

How long have you had it? I ask because it may take a year for new shoots to show up, so don't throw it away until at least another growing season has gone by.

Hmm. I'll keep the nandina's if they don't die. I have had them for about 1.5 years.

It occurs to me I did not upload pictures of these. Here they are:

Nandinas when first planted:
http://i232.photobucket.com/albums/e...4/CIMG2256.jpg

Nandina's 2/2009 (these were never pruned):
http://i232.photobucket.com/albums/e...4/CIMG2957.jpg

Nandina's last month:
http://i232.photobucket.com/albums/e...4/CIMG3326.jpg

The one closes to the water spicket looks OK, the others dropped a lot of leaves, and are still red'ish... Ideas?

Quote:

Originally Posted by bugman-74

Thanks for the reply! I will try to cut back watering the salvias... Unfortunately I only have one circuit on the drip system. There are currently two drip lines to each salvia, so I could probably plug one, and reduce the other to a lower GPH emitter, if you think that would work?

That would be the direction I would go, then if you decide to place more plants in this area, all you'd have to do is reverse the adjustment.

Quote:

Originally Posted by bugman-74

This is what it looked like when they were planted (no idea of the holes were enlarged, or if any special soil was used). Best way to describe the dirt around here is "desert." Its very hard, compacted, and dry.
Our winter low's only drop into the 40's at worst. Perhaps I should wait until February or so to replant the dead one.

The holes look big enough, and I would wait till February to replant.

In the meantime:

You can do this on a hole by hole or all at one time basis, It depends if you have enough room.
I'm going to describe “all at one time”.

Go and purchase enough humus, compost, a small bag of peat moss, and a small bag of crushed not pellitized lime to replace the amount of soil that you can visualize it would take to replace the soil in those 6 holes.

Remove the soil from the holes, make a pile.
Create a similar pile of 50% humus, 40% compost, and 10%of peat moss, sprinkle a small coffee can of lime on top.

Mix but do not over-mix both piles.

Refill empty holes with newly created soil.

You can also place 2 to 4 worms into each hole as you refill.
Water until moist.
Now your ready for replanting in February.

Quote:

Originally Posted by bugman-74

You mean cut them all the way back to where the geen shows in that picture (almost to the ground)? Should I do this now, or wait until Nov/Dec/Jan?

Thanks for the help!

Your welcome.
Yes, that is what I meant, and yes, you can do it now as the plants are in early dormancy.

~~~ ~~~ ~~~~~ ~~~ ~~~

Quote:

Originally Posted by bugman-74

Hmm. I'll keep the nandina's if they dont die. I have had them for about 1.5 years.
The one closes to the water spicket looks OK, the others dropped a lot of leaves, and are still red'ish... Ideas?

In the top, and middle pix we see the three plants growing in unison. The center pix shows a natural dormancy color, whereas the bottom pix shows the two by the window may be under-watered. Your closer, and I can see some red, but they look more brown than red on my screen.
It's not unheard of, that a hose will have leakage, and plants closest to it will flourish better.

If you have the drip running to this area also, check the emitters, and piping to see if they are blocked. If not on the drip, then you'll have to increase the watering frequency (WF) manually.
Water then trim them back to green. Use the remaining Nandina as a guide, and when it starts to turn red then you can decrease the WF.

This could also be a case of an animal, wild or domesticated, marking its territory, and those two are going to perish no matter what you do.

I would normally worry 'bout foundation damage with Nandia, but being in Tucson, your probably on a slab, with no basement, but I would still remain vigilant.
http://www.invasive.org/weedcd/pdfs/wow/nandina.pdf
sacred bamboo: Nandina domestica (Ranunculales: Berberidaceae)