Germination Temperatures

[palmsOrl]

I used the search feature but was unable to find any specific answers to my question, so here it goes. I recently received an order from rps, I soaked the seeds, and sowed them in moist coco coir medium in a clear plastic container. I then placed them in an outdoor storage closet with a space heater for heat (didn't want to fuss with heating mats, etc.). The heater has a rather imprecise thermostat and though I've tried to keep temperatures a steady 90-92 F they have been around 99 F during the day and 92 F at night. The seeds in question are Areca minuta and Cyrtostachys loriae. Is this an acceptable temperature range for tropical palm seed germination? Just how hot is too hot? Thanks in advance!

-Michael

[John in Andalucia]

Your temperature range definitely sounds excessive. I would aim for 90-92F max. during the day and nearer 84-86F overnight. Somewhere in that range will do for most tropical seeds.

[Tyrone]

I agree. The palms origins can give an indication of what temps it will handle and what ones will cook them. Generally in the tropics it doesn't reach 99F (approx 38C). Prolonged exposure to those sort of temps may kill the seed. Desert species may handle those sort of temps with ease though.

Best regards

Tyrone

[Trópico]

Hey palmsOrl

Use a Glad clear container with moist vermiculite for small seeds or moist peat/perlite for large seeds. Seal. Store outdoors in the warmest shade you can find. No artificial heating required unless it's winter. Good luck!

Edited September 16, 2009 by Trópico

[palmsOrl]

Wow, thank you for your responses. I hope I didn't kill the seeds, but I can't imagine mid to upper 90s for 2 days would kill them (maybe 105-110) when they do best with 90-92. Nonetheless, I reduce the heat substantially. The reason I decided on applying the heat is because I read from several sources that tropical seeds did best around 90 F, and our avg. temps here over the next month will be approx. upper 80s for highs and 65-72 for lows. This means an avg. temp in the upper 70s, significantly cooler than ideal for the tropical seeds. Maybe I'm over-thinking it , I have just had such poor luck with palm seeds in the past, that I am determined to do it right this time.

[Matt in SD]

I've tried several different germination methods, and more than once found that warmer temps (90s F) led to more rapid germination, but also more rot and lower overall germination rates (i.e. a few seeds sprouted fast, the rest died). I've had much better luck with cooler temps. I germinate in an unheated greenhouse, which is probably pretty similar in average temps to what you would see outdoors in Orlando. If you can get a hold of some thick walled styrofoam shipping boxes (the kind that are used to ship items frozen in dry ice) these are really magical for germinating. They keep the moisture more evenly distributed because you don't get condensation on the top and sides, and they also average out the high and low temps, but still allow a bit of day to night temp fluctuation...actually I don't know why they work so well, but I've settled on these after trying nearly every method I've heard of. If you get the deep boxes, you can leave space at the top and let the seedlings grow their first couple leaves in there (yes in the dark, they don't mind at all).

Matt

[palmsOrl]

Great information Matt, thank you. I am currently using one of those tupperware tubs and have been opening it once a day to let fresh air in. I have adjusted the temps so that they are around 85 at night and 93 during the day. When I went to rehydrate the cocopeat, I added a bit of physan to ward off fungal issues. Will have to remember the styrofoam boxes for next time.

-Michael

[chris.oz]

I've tried several different germination methods, and more than once found that warmer temps (90s F) led to more rapid germination, but also more rot and lower overall germination rates (i.e. a few seeds sprouted fast, the rest died). I've had much better luck with cooler temps. I germinate in an unheated greenhouse, which is probably pretty similar in average temps to what you would see outdoors in Orlando. If you can get a hold of some thick walled styrofoam shipping boxes (the kind that are used to ship items frozen in dry ice) these are really magical for germinating. They keep the moisture more evenly distributed because you don't get condensation on the top and sides, and they also average out the high and low temps, but still allow a bit of day to night temp fluctuation...actually I don't know why they work so well, but I've settled on these after trying nearly every method I've heard of. If you get the deep boxes, you can leave space at the top and let the seedlings grow their first couple leaves in there (yes in the dark, they don't mind at all).

Matt

Matt,

I also used the large styrofoam boxes to good effect, but with bulk qtys of Howea seed.

It was very successful, but actually howea tolerates very rotten medium quite well.

But beware, the roots easily penetrate the styrofoam, so when you try to remove them to pot them up, you either break the roots or pull out a

clump of styrofaom granules.

[Corrosion]

hmm does anyone know why my bangalow palm seeds have fungus while they are in sterile soil (in theory, I boiled it in my microwave owen)l and the seeds were soaked in bleach water?? I put them in zip lock bags about week ago and I have kept them on the aquarium lamp.. What should I do next? Resoak them and put them back in the bag? I have heard the they manage to germinate in water also when changed daily.

Looking forward to your replies palm pros.

PS. sorry for the thread hijack, but its still related to a germination..

[Alicehunter2000]

Maybe this is why I havn't gotten success with some of my seeds.........to hot in tool shed. Styrofoam sound like a good idea, especially for larger batches. Why not use styrofoam in conjunction with smaller tupperware containers without tops (placed inside) to avoid roots going into the foam and to seperate different species and batches. Actually, why wouldn't any old cooler work.

[Matt in SD]

My last couple batches of seeds in the stryofoam containers, I've put plastic lining in to prevent the roots from going in. It's definitely a problem, I've killed several seedlings trying to get the roots out of the styrofoam. But I think the plastic liner will work. The styrofoam boxes I'm using are very thick, so they insulate extremely well, I think a cooler would work, but probably not as well. They can have dry ice inside and the outside is not noticeably cool. The one's I use also seal nearly completely so you only have to mist every 6 months or so.

Matt

[freakypalmguy]

My last couple batches of seeds in the stryofoam containers, I've put plastic lining in to prevent the roots from going in. It's definitely a problem, I've killed several seedlings trying to get the roots out of the styrofoam. But I think the plastic liner will work. The styrofoam boxes I'm using are very thick, so they insulate extremely well, I think a cooler would work, but probably not as well. They can have dry ice inside and the outside is not noticeably cool. The one's I use also seal nearly completely so you only have to mist every 6 months or so.

Matt

Matt,

Do you have any pictures of the boxes you are describing?

Matt

[palmsOrl]

Update. Thank you again everybody for all the help in getting my germination temperatures correct. I briefly open my two germination containers every day to allow a bit of fresh air into them. Today I noticed a bit of white fuzz (some kind of mold I'm guessing) starting to grow on the coco coir medium's surface. When I hydrated the coco coir before sowing I used distilled H2O with a bit of physan added to prevent just such problems (fungus, damping off, mold, etc.). I really would like not to have to add anymore fungicides or other chemicals to the germination containers, but I might have no other choice. What should I do to get rid of this mold growth, without inhibiting germination? How harmful is this white fuzz to germinating seeds? Thanks in advance!

-Michael

[Matt in SD]

Matt, do a google image search for "dry ice shipping cooler", there are several photos.

Michael, there is no need to open the containers. The seeds don't need fresh air, and even the seedlings can go to the 2 leaf stage with basically no air circulation at all. If you do let the leaves develop with the container sealed though, it's worth spraying an anti-transpirant on them when you pot them up as the drop in humidity (less problem in Florida than CA) can be a big problem.

I'm really surprised you're getting fungus on the coco-peat. I've used coco-peat for years now, with no fungicide at all and never once seen mold grow on it. That's one of the reason's it's such a great medium for germinating. Maybe it will go away on it's own?

Matt

[John in Andalucia]

Coir varies in quality (and price). I buy unwrapped bricks of the stuff off pallets for the equivalent price of 0.88 USD. I know nothing about the manufacturing process, but it's always a good idea to pre-mix a quantity and zap it in the microwave to guarantee a sterile mix. If you only had a few rare seeds, I wouldn't ever dismiss doing this.

[Tyrone]

I find that good seed will tend to resist fungal issues provided the fungus hasn't gone crazy and taken over everything.

Also fungicides do not kill fungus, they merely supress fungus. Almost nothing kills fungus and it's spores totally. Phytophthora spores can exist as either dry weather spores or wet weather spores and stay dormant until appropriate conditions arrive for some years.

Best regards

Tyrone

[palmsOrl]

It appears to be good quality coco coir, and I brought the distilled water to a boil and then dumped the coco coir in to sterilize it. Despite this, mold spores are in the air all over the place, so they must've settled onto the surface after the fact. From looking online about this issue (white mold), I've decided I am going to dip a q-tip in a 50/50 solution of water and hydrogen peroxide, then dab the q-tip on the areas of mold growth to keep it under control. We shall see how this works...

-Michael

[Trópico]

How are your Cyrtostachys seeds doing? Can you give us an update?

[palmsOrl]

Hey there Frank! The seeds have now been cooking for 20 days and there aren't any signs of germination yet. I'm not exactly sure how long it should take for Cyrtostachys loriae. I recently read in a palm book that C. reda take between 8-12 weeks, so I may be waiting a while yet. That book also said that ideal germination temperatures are 95-100 F, but I'm keeping mine around 90 F. I went to the rainforest collection sale on Friday and got a large Cyrtostachys glauca specimen, you should've seen how we fit it(or at least most of it) in my car I will post pictures of it, and hopefully some newly germinated seeds shortly.

-Michael

[palman]

90F is ok but maintain ventilation while they germinate.

[Little Palm]

Yes, they should pop in about 8 weeks with 90 F temp and kept moist. Good luck and keep us posted with some pics.

LP

[palmsOrl]

Will do, thank you for the bode of encouragement. It's been 29 days, and since there is no germination data specifically for Cyrtostachys loriae and Areca minuta on rps, I don't know what to expect. I open up the tops for about 30 seconds every day to provide a bit of air movement for them, and am making sure that the coir stays moist (though not wet). I will get pics when I get a chance and will keep you posted!

-Michael