annuals dying one by one

17 years ago

I have a problem with annuals dying one by one.

They are in a mixed flower bed, morning sun, afternoon shade.

Two years ago I put impatiens in my flower bed and one by one they wilted away and died. Last year I did non-stop begonnias and they did fine there.

This year, my non stop begonnias are starting to die off like the impatiens did. I dug a plant up, and it seems that they are dying at the base of the stems. The root looks good and the stem just below the soil is still firm. The plant wilts, and then just lifts off the ground, leaving a good root still in the soil. The problem seems to be occurring above the ground. The soil looks good, not too wet, not too dry.

I gave them a 10-30-10 fertilizer shortly after transplanting. They get rain water from our rain barrels, only when required. They have good drainage and some compost was worked into the soil prior to planting.

We are seasoned gardeners and the rest of our garden does very well. We are stumped on this one bed though.

Anybody have any ideas?

Featured Answer

gardenerme

17 years ago

IMHO, you have crown rot. It normally occurs very soon after planting, the plant begins to wither and quickly dies. I killed whole flats of petunias before I figured it out. The best way to avoid it is to PLANT HIGH!!! It won't cost you a dime and makes planting a whole lot faster.

We all treat out plants like children at bedtime. We carefully dig the hole, place the plant, and then tuck it in well by pushing the soil up around the crown. WRONG!!!!!!!!

99% of plants like to be planted with the crown a good inch above the soil line. (There are a few plants that like their crowns buried, like tomatoes, peonies, clematis, hybrid tea roses if your ground freezes.) If you watch professional gardeners planting annual displays, they stab the soil with a hand trowel, plop in the plant (usually 4") and move on to the next one. No tucking in, no special treatment. And these displays will look terrific for months. I would also treat the area for slugs, snails, etc, so your fresh plants don't become the freshest salad bar in town. Just remember, PLANT HIGH!!!!!!!!

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Comments (7)

omniphasic
17 years ago
Sounds like you need to replace the soil where you planted these things.I'll always advocate using fresh soil whenever you plant something new.Using Osmocote at planting time makes a big difference as well...do a ''test'' garden using osmocote in one area and one area without...you'll be amazed by the results.
davemichigan
17 years ago
Has the bed ever been good before and then gradually turned bad? Or it has always been bad?

You have added compost and fertilizer, so I don't think it is nutrient deficiency. I was going to suggest that the fertilizer might be too strong, but I assume you are using the fertilizer and the water the same way in other areas of the garden.

Maybe the salt content of this bed is high? Just a pure guess though.
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teresaslc
17 years ago
I too, am a seasoned gardener and had this headscratching problem occur over and over again, sometimes with recently planted annuals and often with well established ones. A perfectly healthy plant would wither almost overnight, and you could just pick up the remains off the top of the soil. After years of trying to figure this out, digging up the soil, closely examining the plants, etc., I discovered that tiny slugs and/or snails were the culprits. They severed through the main stem of the plants. Since I interplant 10 to 12 flats of annuals among my perennials every year, this is a big problem. The only solution I've come up with is to use a liquid snail killer to draw a circle completely around each newly planted annual. Somewhat expensive, but better than losing all your plants to those little buggers. If you have a lot of well established perennials they can hide under, the problem is worse. Best of luck to you...Teresa in SLC
zen_man
17 years ago
My favorite slug control is a product called Sluggo. It seems to be effective, while remaining safe in the environment. It is available at many garden centers, as well as online.

ZM
User
Original Author
17 years ago
I 'googled' stem rotting base of plant', and I think I got an answer.
'Basil Stem Rot', a type of Crown and Stem rot.
It's a fungus that develops at the base of the stem, due to overwatering (oops!), cold weather and little ventilation.
There isn't much I can do about this now. The plants that are affected will eventually die off.
It has taken a long time to warm up here in southern Ontario. Next time I'll be careful with my watering schedule.
I know others in this area that have had similar problems.
The lack of warm weather is preventing the plants from soaking up the water i guess.

Here is a link that might be useful: Crown and Stem rot
oilpainter
17 years ago
You have a fungal problem that has infected the soil of the bed If it has gone on for this long probably the whole bed is infected and short of replacing the soil,solarization may be your only option now. Cover the whole bed with black plastic and leave it on all summer. The heat built up under the plastic will kill the fungal spores. Next year you will be able to plant there again. Or you can try one of the fungicides mentioned below.They are taken from a University of Kentucky website I found and saved a long while ago. I tried to find the link but couldn't. I think your problem may be one of these, so I'm giving you both

Southern stem blight (fungus)
Symptoms: Plants wilt and die in patches in the bed. Small,
brown to yellow-brown, spherical sclerotia may be observed
clinging to rotted stems at the base of the plant. The sclerotia are
often embedded in white fungal mycelium on the stem surface.
Control: Remove dead plants and 6 inches of surrounding
soil and replace with clean soil or use another kind of
plant. In nurseries, PCNB fungicide can be used.

Â Botrytis blight (fungus)
Symptoms: Dead blotches appear on leaves, flowers, and
stems. Stems may rot and plants collapse. Flower buds may fail
to open. Diseased flowers decay and fall prematurely. Affected
areas may be covered with fuzzy fungal growth and spores.
Control: Destroy old plant debris in the fall. Avoid
wetting foliage. Prune out nearby shading vegetation. Provide
adequate plant spacing. Use fungicides such as
chlorothalonil, dicloran, ferbam, iprodione, mancozeb,
maneb, thiophanate-methyl, vinclozolin, or mancozeb +
thiophanate-methyl. Read the label for lists of specific
plants allowed for each fungicide.