I've been growing Celosia, the giant 48-inch tall cockscomb variety, in the
house for about the past 10 weeks. They are in front of a window where they get
full sun for about 4 to 5 hours per day. The vast majority of them still don't
seem hardy enough to plant outside. I slowly placed one tray of them outside,
about 20 minutes per day, building up to about 5 hours per day. They were fine
until I reached about 5 hours exposure but then started to appear burned and
about half of them died. I never had that happen before. Usually that's a slow
enough exposure they do fine outside. So I decided to keep the remaining ones
inside until they got a bit bigger.

Now several of the remaining plants, the ones that have never been outside,
seem to be withering and appear in serious trouble. Some have died. They appear
healthy, about 2 to 3 inches high with at least two sets of leafs, then
suddenly wither and die. I keep them pretty dry since I've heard they are very
vulnerable to damp over and like it very dry. I water them by spray misting
them most of the time. Sometimes I use a small dipper and water them a little
heavier but not often. Increasing the water to any plant that starts to wilt
never seems to help.

I had about 68 plants and am now down to about 40 and still have none planted
outside. (It's been unseasonably cold and rainy here and likely not suitable
outside yet for these plants.) I love these plants but only get about 14 to 20
every year that make it to full size.

Does anyone have any tips or advice for doing better with giant celosia?

You don't say where you're located, so it's hard to know what you're trying
to protect the plants from by keeping them indoors until mid-June. Here in
Rochester NY, it's also been chilly and rainy, but the nurseries still have
annuals out on the tables, unprotected, and they're doing fine. My seedling
trays began going outside in mid-May, with a watchful eye on the weather
forecasts for the nights. I start by putting them in shade for the first few
days, and then gradually giving them more sun by the end of the 2nd week.

Some suggestions:

1) Stop misting them. It serves no purpose, especially when the weather's
damp and dim. 99% of the plants you grow get their water from their roots.
By misting, you are inviting damping-off and other fungal diseases. Stop
now.

2) Watering: The right way is to pour water onto the soil, and if it wants
to drain out the bottom of the container, let it drain out. Don't let the
pots sit in that water, so water over the sink or something, or lift the
pots into another tray while you dump the excess water. The only reason to
let pots sit right in water is if you've let them get bone-dry. Some soil
mixes with peat moss will refuse to soak up water readily if they've gotten
too dry.

3) You don't say exactly how you've got them planted. Are they growing in
trays with no drainage holes? If so, it's hard to water them correctly. When
using tap water, you want the water to flush through the pot, which
minimizes the buildup of whatever minerals are in your water.

4) Tap water often contains chlorine, and some plants are more sensitive to
it than others. Store your plant water in a large bucket overnight,
uncovered, and most of the chlorine should dissipate. This is not related to
#3. Correct watering will not do away with chlorine. Correct water storage
will. And, if your water treated in any way, perhaps with a water softener?

5) Is there any kind of gas appliance, gas fireplace or gas furnace in the
same room as your plants? Answer this question and I'll explain further.

6) Timing: The paragraph below, from the National Garden Association,
recommends starting celosia no more than a month before last frost date.
Yours are 10 weeks old. Assuming you were in chilly Canada, and the NGA
erred on the short side, I'd still split the difference. I start mine in
late April, for planting around Memorial Day. Yours are indoors too long,
and don't have time to develop enough stem strength to deal with wind. Their
leaves are frilly, so if they flop on the ground, they're highly likely to
rot or be otherwise damaged.

"Celosia or cockscomb is a warm season annual and needs full sun and a warm
soil in order to do well, so do not plant it too early. In terms of water,
it is both heat and drought tolerant but a normal soil moisture level will
help it produce bigger blooms. Seeds would be started no more than a month
before the last frost date with transplanting being done when the soil has
warmed."

Doug

"GSHATTERHAND" wrote in message
...
I've been growing Celosia, the giant 48-inch tall cockscomb variety, in
the
house for about the past 10 weeks. They are in front of a window where
they get
full sun for about 4 to 5 hours per day. The vast majority of them still
don't
seem hardy enough to plant outside. I slowly placed one tray of them
outside,
about 20 minutes per day, building up to about 5 hours per day. They were
fine
until I reached about 5 hours exposure but then started to appear burned
and
about half of them died. I never had that happen before. Usually that's a
slow
enough exposure they do fine outside. So I decided to keep the remaining
ones
inside until they got a bit bigger.

Now several of the remaining plants, the ones that have never been
outside,
seem to be withering and appear in serious trouble. Some have died. They
appear
healthy, about 2 to 3 inches high with at least two sets of leafs, then
suddenly wither and die. I keep them pretty dry since I've heard they are
very
vulnerable to damp over and like it very dry. I water them by spray
misting
them most of the time. Sometimes I use a small dipper and water them a
little
heavier but not often. Increasing the water to any plant that starts to
wilt
never seems to help.

I had about 68 plants and am now down to about 40 and still have none
planted
outside. (It's been unseasonably cold and rainy here and likely not
suitable
outside yet for these plants.) I love these plants but only get about 14
to 20
every year that make it to full size.

Does anyone have any tips or advice for doing better with giant celosia?

Thank you, Doug, for all the suggestions.

I live in Cleveland, OH.

I will stop misting them and water my celosia by pouring water onto the soil.
They are planted in variously sized small pots all with drainage holes. I will
also try storing my plant water in a bucket overnight in case the chlorine is
harmful to them.

There is a hot water heater in the same room as the plants. No other appliance
in the room that uses gas. You are right, of course, these plants have been
indoors too long already. Much longer than any previous year.

"GSHATTERHAND" wrote in message
...
Thank you, Doug, for all the suggestions.

I live in Cleveland, OH.

I will stop misting them and water my celosia by pouring water onto the
soil.
They are planted in variously sized small pots all with drainage holes. I
will
also try storing my plant water in a bucket overnight in case the chlorine
is
harmful to them.

There is a hot water heater in the same room as the plants. No other
appliance
in the room that uses gas. You are right, of course, these plants have
been
indoors too long already. Much longer than any previous year.

I asked about gas appliances because even miniscule amounts of natural gas
will kill seedlings. I used to start my seeds in my basement, where there
was a very old furnace which released just a puff of gas before it ignited.
It was enough for me to smell, for just a few seconds of each heating cycle.
A local gardening article tipped me off to the problem, and it said that the
amount needed to harm seedlings can be so little that you won't detect it.

If you're curious, your local power company will stop by for free and
measure for leaks.