Mini Den cultural info needed! Help!

[shakkai]

I needed to find more information on three species: agathodaemonis, cyanocentrum & vexillarius.

I know that agathodaemonis now seems to be considered the same as cuthbertsonii, so I will assume conditions should be the same - unless someone tells me otherwise!

They are listed here:
Equatorial Plant Company Flasks
as follows:

Dendrobium agathodaemonis - IOSPE PHOTOS
Oxyglossum
Miniature with red cuthbertsonii-like flowers. Cool.

Dendrobium cyanocentrum - IOSPE PHOTOS
Oxyglossum
Miniature, cobalt blue flowers. Intermediate/cool.

Dendrobium vexillarius - IOSPE PHOTOS
Oxyglossum
Small plant with bright orange flowers. Cool

What I'm really hoping are some max/min temps - rather than just a 'cool' guideline which varies quite a lot in interpretation. Is it cool like cuthbertsonii, or cool like jacobsonii (bordering on cold)?

I'd also really like to find out light and water recommendations/requirements.

I'm really struggling with the cyanocentrum. It seemed to be doing well, and putting out new growth in cool conditions, but then it started to go downhill and all of the new growth died back. I tried moving it to more intermediate conditions, but then established leaves started dropping. I am assuming that this isn't one of the dens that drops all of its leaves and goes through a rest period, so something it definitely wrong and I need to fix it before I lose the plant. The roots are still white/green (but are no longer growing) its the canes that are dying back.

These came potted in sphag, but I'm wondering if maybe they would do better mounted, as most of the photos appear to show them mounted.

[Phantasm]

Most of the New Guinea oxyglossum Dendrobiums need a cool and moist environment. Preferred temperatures are on the cool side of intermediate with more tolerance towards cold than warm. I would try to keep them below 75F and preferably 70F. Low temperatures can go almost to freezing, but 45-55F is best.

Your problem could be the moss breaking down. It turns more acidy over time, especially with a bit of fertilizer to help it. A well watered mount probably works best if you can mist it often during dry or warm temperatures.

These plants tend to flourish for a while, then go downhill quickly if they are not happy. Good Luck!

They are certainly very beautiful and rewarding to grow.

[shakkai]

Thanks for the extra info! I was keeping them in the ExoTerra tank with my Pleurothallids. Min/max temps there so far for November are a high of 60F and a low of 48F. (Summer months are obviously warmer, but don't really rise much above 70F ever, or not for very long if they do.)

I took a chance on these after I found the cuthbertsonii seemed so happy. It is still doing really well, and I've no problems yet with the agathodaemonis or the vexillarius. But seeing the cyanocentrum deteriorate so quickly, I wanted to head off any potential problems with the others.

I've had the cuthbertsonii the longest and it is not in sphag, and I think I'll leave that one alone, as it seems really happy. But the others are going to go onto a cork mount - tonight!! That way, I'll be able to keep them moist, but I can be sure that the environment around their roots stays fresh.

Thanks so much for the suggestions and help!! I really hope I can get them happy enough to flower.

[linda_shel]

Dendrobium cyanocentrum information from Baker = Light:1000-1800fc Growers recommend shady conditions.
Temperatures: Throughout the year, days average 28-30C(82-85F), nights 17-19C(62-66F), diurnal range 11-12C(19-22F). Average highs and lows vary only slightly during the year indicating that plants are unlikely to be healthy under widely fluctuating temperatures.
Rest Period: Growing temperatures should be maintained all year. Water should be reduced in winter. Plants should dry slightly between waterings, but they should never be allowed to dry out completely. Fertilizer should be reduced or eliminated until water is increased in spring. In the habitat, winter light may be slightly higher.
Humidity: 70-75% in summer and autumn, dropping to 65-70% in winter and spring. Fertilizer: 1é4-1é2 recommended strength. A balanced fertilizer should be applied weekly to biweekly throughout the year.
Water: Rainfall is moderate to heavy most of the year but is relatively low for 2-3 months in winter. However, additional moisture is available from dew, fog, and mist, even during periods when rainfall is low. Cultivated plants should be kept moist but not soggy. Additional early morning mistings between waterings are often beneficial, especially on warm, bright, sunny days.
Growing Media: Plants may be mounted on tree-fern or cork slabs if humidity is high and plants are watered at least once daily in summer. Plants adhere firmly to tree bark. When plants are potted, any open, fast-draining medium may be used. Repotting may be done anytime new roots are growing.

[shakkai]

Thanks, Linda! This makes me question whether I should be keeping the cyanocentrum with the others. The other ones are definitely cool growers, whereas those temps you posted are what I'm growing Phals in....

Hmmmm.....