Phalaenopsis Growth Stalling and Bud Drop

[naturally_stylish]

Hi,

This is my first post so please be gentle!

I have been collecting phalaenopsis and oncidium orchids for a little while and have found this site invaluable for its depth of information. Normally I have been able to read about a solution to any problem I've experienced but I would love some expert one on one advice to this problem.

Over the past month all of my phalaenopsis orchids which had started flower spikes have stopped, some of the spikes had buds but these have all shriveled up and died (bud blast). Others have small spikes between 1cm and 10cm but they are stuck at this size.

This is my first season growing orchids from seedlings as in the past I had bought flowering size so I'm not sure what I'm doing wrong that is causing the problem. I only had one oncidium in spike but that has flowered with no problems.

The plants are all grown inside my home and I live in QLD Australia with day temps of around 21 celcius and nights around 19 celcius. I have no gas cookers or fires and the plants are not being moved around or receiving any cold breezes. I use a combination of perlite and bark as my growing medium and I fertilize fortnightly using 22-8-12 one fortnight and 12-12-20 the second fortnight.

All my plants are healthy with good root systems.

The only thing I could think of was I had the outside of my home sprayed for pests around 6 weeks ago, could this of caused the problem and would it still be an issue?

I grow the orchids as I love having their blooms around my home so I hope someone can help as its very frustrating!

[WhiteRabbit]

Thanks for including many details of the growing conditions!

I don't think spraying for pests outside would likely cause the bud drop, etc., but perhaps some other members will know.

Everything sounds pretty good ... No recent, significant temperature fluctuations?

[naoki]

Are you growing hybrids? The following info may not apply to hybrids, but I've heard that with some Phal species, it is a symptom that you don't have enough diurnal temperature fluctuation. The info is from Japanese version of: Cultivation of Palaenopsis He didn't translate the section which discuss about this issue in English version. I haven't had any experience with this (I've never lived in such climate), and I haven't quite understood the physiological reasons why some orchids require this day/night temp fluctuation.

I've seen that young seedlings of Phal species sometime makes the flower shoot, but don't flower at the first season.

Some pesticides could have such effect. Which one did you use?

[My Green Pets]

A photo of the growing area might help.

Why would the spikes freeze and buds blast? Temperature, humidity, and/or water are my first guesses. Naoki's got a good suggestion with the night/day temps, what's the story there?

[Island Girl]

Welcome to the OB! Glad to have you join!! I agree with Naoki, sometimes seedlings start inflorences, and stop them... Species often have "evergreen" spikes (inflorences), which do not die back after flowering, they just re-bloom on the same spike year after year. So sometimes the seedlings seem to get a kind of "jump start" on blooming, at least, this is my theory, so they are ready when they r old/big enough/have enough built-up energy, to be able to bloom. That is, if you were referring to your seedlings doing this...

If its adults... I'm not sure, if nothing has changed culture-wise, and you have gotten them to re-bloom in the same spot, with the same conditions? But will say, that if the drop in temps isnt right (by 10°-15°) then, they won't bloom... Maybe at night, the temps didn't drop sufficiently, or for long enough? (needs to be two-three weeks, of night temps being 10°-15° cooler than the day)

[naturally_stylish]

Thank you everyone for the warm welcome and helpful advice.

White Rabbit I grow all my orchids inside so the temps are pretty constant (perhaps a little too constant!) but I did contact my local orchid breeder who I had purchased two large plants from in bud and ready to flower, but who subsequently dropped their buds, and he said they had a couple of really cold nights recently and had experienced a lot of bud drop on their plants so I guess that explains those two. Now to solve the problem of my seedlings and flowering size babies!

Naoki I had never really thought of the night/day temperature difference so as of tonight I will try opening the bathroom window (where my flowering size babies are kept) to see if we can lower the temperature and encourage them to bloom! Thank you also for the link I'd never came across that site before and it has lots of interesting reading on it

CambriaWhat I grow the plants throughout my house so each area is different but I will try and take some pics and post them soon. I have three children under 6 so it can be a little hectic here most days but I'll try and do it this weekend as I know it may help.

With regards to watering I have found that the tops of the pots seem to dry out quite quickly while the bottom stays damper longer. The problem with this is the roots at the bottom are fat and squishy while the ones at the top go dry and wrinkly, how do you solve this problem?

Island Girl I’m afraid I haven’t had the orchids long enough for them to experience a rebloom as yet. I’m ashamed to admit but up until late last year I was one of those known as “phal abusers”. I thought they were like cut flowers and once they had finished blooming I would put them outside and overwater them until they eventually died. It was only when purchasing yet another orchid from the same store that the helpful clerk decided to give me some orchid care 101 and set me upon my orchid obsessed path.

[Island Girl]

Lol, that's ok, we all started somewhere, and have certainly killed our share!

Wow! Three kids under six! ....so you're not too busy at all right? Lol

When the top of the medium dries out, and the bottom/middle hasn't yet, I just mist the surface of the media, along with the roots/aerial roots.... Just try to keep water from getting in the crown (*esp. when temps are going to get below 60°F at night*), and to help prevent problems, do it early in the morning. Also, while I'm talking about watering, I suggest for you to do a search of this forum, for the "skewer method"... That will help you to know when to water, and when not to. With time, you will be able to tell by the weight of the pot... Just lift it when it's completely dry/or when it needs watering (according to the skewer), and then lift again after you water.

Btw, I like your name naturally_stylish! (still impressed you can keep up w/ three kids under 6!)

[naoki]

I'm guessing that your phal is a hybrid. Then I'm not sure if the temperature difference between day and night is important. Probably not. I think your night temp is good for most Phals. So you probably don't have to make it cooler.

I don't know the climate of QLD, but are you using Air conditioner frequently? Low humidity could cause bud drop in some plants.