That depends.
I lost tons of amaryllis bulbs after repeated overhead soaking and subsequent invasion by tarsonemid mites Steneotarsonemus laticeps then superinfection from Red Blotch Stagonospora curtisii that eventually turned the bulbs into a rotten pulp. The most deplorable loss was "Flamingo".
Now, I have plenty of place for my bulbs, safe from rain, but "Flamingo" is irreversibly gone. And so are "Dotted Panties" and "MinPic" (="Minerva" x "Picotee", father of "PapMinPic"), and "Amarena Balls"

Hello, so I must spray them with fungicid + insectiside now and again at the end of rains. Thanks
Arif

Hippeastrum really do not like frequent watering of rain. Apart from the fact that the leaves when wet stagonospora affected, the more rainwater contains spores of this disease. They are spread by wind over long distances.

Oh no! I was so happy to see my outdoor bulbs getting nice and fat - but we have been having torrential rains and I have too many to cover effectively. So now I should be worried? Any practical advice?

To cover effectively or must spray them with fungicide.

Don't be worried about the rain, these plants THRIVE in tropical situations just DON'T let them get too wet in dormancy!

If they're responding nicely then nothing is wrong just make sure to treat for illness!

Josh

Josh.
Yes, don't be worried. But since when in the fall of Quebec outside tropical conditions? :))

"tropical"
correct.
Cold weather will reduce, in the the growing crop, the intrinsic powers of resistance, and fungal infection promoted by humidity, spreading from the leaf bases into the core of the bulbs, will become detrimental, and if not cured at a very early point then LETHAL.

Hi

Are we speaking of plants in the ground.. or plants in plastic pots.. or plants in clay pots? It would seem to me than all three would have very different drying out times and requirements for possible fungal prevention..clay pots even after soaked for a few days will dry out in just a few sunny days. In the ground, the roots are all spread out and drain easily in my sandy soil. My opinion would be that the plants most susceptible to fungus due to excessive moisture would be the plants in plastic pots..of which I only have one....just my opinion..now a WEEK of cold.. or tropical rains might be another story.

By the way, we recycled two garden carts that we found at the local dump and found them so useful that we bought two more..each holding 18 to 24 plants depending on pot size. They can be easily rolled in our garage or under a covered deck..Hubby finds this method of moving all my plants around much more tolerable!! During hurricane Irene, we even rolled two of them in the house! We are all on a dump watch for two more..otherwise, maybe Santa will bring me two for Chrismas....;-)

Donna

As to what I refer to - the kind of containers makes no difference. When there is water standing between the leaves, and the bulb scales are repeatedly soaked then the tarsonemid mites are encouraged to migrate from the periphery (where their impact is negligible) to the core of the bulb.

But water between leaves is natural, no? I mean, that's what happens to the plants when they are out there in the "wild". My pots are all plastic, and the weather is supposed to be be quite warm through most of September. But I fully realize that cold temps, especially at night, are not good, and so the bulbs will be heading to their winter basement dwelling before the end of September. The torrential rains I was referring to, were associated with Hurricane Irene - the first time we have ever had hurricane-type weather up here. Very warm, and lots (100mm+) of rain.

Water between leaves is totally natural. This raises the question, whether infection with tarsonemid mites is natural. Bulbs that are not contaminated by this pest WILL withstand prolonged soaking even under cold temperatures much better.
I am yet to learn, "from where these mites came to Amaryllids" I strongly PREsume that these mites had not always been a pest to these group of plants.

How do I know if the bulbs have any mites - what signs do they exhibit?

Needle-sharp, red streaks on fleshy parts of bulb scales
needle-sharp, brownish lines on the backside of the leaves composed out of numerous dots in regular distance after one-another. Sawteeth-shaped deformities on one or both edges of young leaves. I blame Veronica Readthat she diod not include speaking illustrationsinto her book. THAT would have taught the people and sharepened their sense of observation respectively.
I shall include some picture tomorrow, of the dotted-line thing. I have some Eucharis, that demonstrate this very well.

Oleg,

Quebec isn't a tropical location but it is summer and their summers are warm. Here in northern Indiana in zone 5 we have very tropical summers where my Hippeastrum are supplied with tons of natural rainfall and thrive. Of course our winters are very cold so they come inside.

Josh

Would the line on this scape of Desire be the tarsonemid mite? This bulb performed admirably for me this winter and is summering somewhere outside seemingly OK, but I have to check. Late spring or very early summer I put a teaspoon or so of a granular systemic contain imidacloprid on virtually all my pots. I haven't checked this one lately, but when I can find it, I will I will check it after our 3 days of rain has abated..(I left them all out for 24 hours in the rain, but then had them brought under cover by a less than enthusiastic hubby...

Donna {{gwi:425611}}

That red line is my problum too, but only on few.
Arif

Thank you for showing. Yes this is a typical result from infection with tarsonemid mites. If you monitor how a scape emerges out of the bulb, you perceive that the cross-section of the scape is not a circle but rather oval. And, at both main-zenith points of this ellipsoid, there is a considerable GAP between scape and the two girdling bulb scales. This provides plenty of space for mites to invade the bulb DEEPLY, and this leads to the impact on the scape as shown. If only one gap is being heavily infected, then the scape will grow bended towards the infected side, because the side cannot grow as fast.

Oh no! I have seen that red line too - somewhere. Also, if a scape does not fully emerge, and the blooms unfold when the scape is really really short (1" to 4-5"), is that another sign of mites? Sigh.

Not necessarily.
THIS occurs if/when the bulb has almost no viable roots.

Some time the scape collapses and rot
Will local application of an insecticide be of any help?

Anne, Quebec,
Tell me please, what you have in Quebec is now the minimum temperature (preferably in degrees Celsius) at night?

LOCAL application helps but to a very limited degree.

"What you see" is the aftermath only.
Mites themselves, are hidden between the bulb scales. Only those mites will be killed, that emerge from time to time. Thus, superficial application of an insecticide (with acaricidal efficacy!) will prevent mites from spreading around and infecting surrounding bulbs.

@Oleg - these days we have very warm days up to 20-23C, and at night a range of 8-11C. I know the signs when I should bring my bulbs in - consistent single digits at night, and lack of sun in the place where there used to be lots.

@Hans - my Dancing Queen seems well anchored, hence she must have roots - and all in all looks healthy. Alas, the buds are opening on scape of only 2 inches! But obviously something must be wrong to exhibit such lack of growth :(

From the russian variant of Wikipedia (translation):[citate]Hydrometeorological believe that the summer period shall begin the transition the average daily air temperature 15 degrees Celsius in an upward and ends - the transition of the same mark in a downward [/end of citate],(average daily temp. - it`s need take the maximum daily temperature, add a minimum night and split in half. So, 22+11:2= 15,5.OK, but 20+8:2= 14! Plus, the cold dew, even when no rain.
Unfortunately, the English-language Wikipedia is not the text, but it is written:[citate]the U.S. summer season is commonly regarded as beginning on Memorial Day weekend (the last weekend in May) and ending on Labor Day weekend (the first weekend in September), more closely in line with the meteorological definition.[/end of citate]
But for hippeastrum not important calendar dates, but the temperature, since at temperatures below 15 degrees Celsius they have stopped growing season and they go into hibernation, when all biological and biochemical processes are inhibited. In this state, the plant can not protect themselves from attacks by pathogens. In their natural habitats at this time, a period of drought. Under dry conditions, disease spores do not germinate, so do not get sick hippeastrum.
Which tropics can tell when the night temperatures drop below 10 degrees Celsius?

Oh dear - now I'm really worried! But seriously, I think I get what Oleg is saying - and yet, one year, I left my bulbs out until just before frost (well into October)- and I did not lose one bulb. *Sigh* - taking 100+ bulbs into the basement is big job! This is for sure: I am relentless and stubborn, combine that with Hippeastrum obsession (this autumn I will order at least 10 more) and results in a big challenge for growing these in Quebec. :)

I think the red line on the stem is the cause of Stagonospora Curtisii one of our abhorred enemies. Sometimes I used to have half the stem deformed with the loss of the much awaited bloom. We have a very hot dry summer in Malta so practically all the watering during the growing season is artificial. I do the watering in the mornings and spray with systemic fugicid and a smaal dose of insecticide (to prevent transmition of virusis by insects) every two weeks during the growth season.
We should be getting some rain soon now and I will be more vigilant for red bloch. I have also started cutting off the leaves and this year I will do with a seperate knife for each pot- if posible for each bulb, for the prevention of viruses.The rains come when the plants are dormant and as I keep them outdoor through the winter I spray with systemic fugicide the bare parts of the bulbs and thorourly in between the leftover parts of the leaves.In the last two years I have not had one stem infected. I am very much against pesticides but by using in the ninimum ammounts I have saved my collection and enjoy the yearly blooms. Michael.