Seed failure.

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roseman
Posts: 1
Joined: Sun Nov 14, 2021 5:38 pm

Seed failure.

Post: # 73491Post roseman
Sun Nov 14, 2021 5:56 pm

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Hi Everyone,
This is my first post on the forum. You all seem like great and helpful people here. I’ve been cloning roses for a few years and decided to try my hand at hybridizing this year. I planted my first batch of seeds in plastic jiffy grow trays with sterilized seed mix, about a quarter inch down, with a light mixture of super thrive, experimented with placing them inside and outside (my falls are pretty mild here in Redondo Beach California) and so far the only result from my efforts has been a few roots breaking the surface of the soil. I think maybe I kept my soul too wet. I also stratified for eight weeks in my refrigerator at 34°, and wonder if that was just too cold. Would appreciate any diagnostic help as far as what I did wrong.

roseseek
Posts: 5297
Joined: Sun Dec 11, 2011 6:54 pm
Location: Zone 9b Central California, Sunset Zone 15

Re: Seed failure.

Post: # 73492Post roseseek
Sun Nov 14, 2021 6:39 pm

Welcome! I moved on from these small cell potting types because they were impossible to keep properly moist and they were too subject to temperature extremes. If you have outdoor space, you will very likely benefit from planting in larger boxes outdoors so the soil will retain moisture and you will benefit from the day to night temperature changes. Rains will also assist as the seeds KNOW the difference between hose water and rain. The first issue with your inquiry though is, you didn't indicate how LONG you have waited for germination. I've had some seedlings exit the soil in seven to ten days from planting while others required two years. Literally. Thirty-four degrees isn't too cold, but it may delay germination longer. You also don't mention what type of rose seeds you're planting. Minis seem to germinate significantly faster than some other types and some species can really require a long period of stratification before they cooperate.

I have planted my seeds outdoors for the past 35 years in the San Fernando and Santa Clarita Valleys and now in the Santa Maria Valley. I decided on planting around the week of Thanksgiving many years ago because it was the last of my "spare time" until after the end of the year due to work and family requirements; and it was when the temperatures should fall into the range more suitable for germination and when the rains historically began. Of course, in later years, the temperatures and rains have changed dramatically, but outdoors is still the preferable practice.

If at all possible, I would use wooden boxes, either commercially available planting boxes or a type you can easily and inexpensively make using commonly available supplies. Please feel free to take a look at my blog post about it here. http://pushingtheroseenvelope.blogspot. ... ables.html I've been using these boxes for the past nearly 30 years with good results. Each one holds approximately four cubic feet of potting soil, giving seedlings plenty of root room to develop. If you build a frame about 18" tall above the box and staple either nylon window screen or plastic hardware cloth over three sides and the top, while leaving the bottom of the side you most easily access the table free so you may flip the side over the top to gain access, you can keep any rodents and birds out of the table as both ADORE rose seeds! The high frame over the top will allow seedlings to grow taller and provide you some time before you must remove them so that can be scheduled to your time, energy and the weather.

Of course you can create smaller versions of the above to fit your desires and needs. You just want them large enough to prevent being overheated in direct sun and by any "unseasonably hot, windy" weather events, which are more and more frequent. Also, living in similar conditions to where you are, I have found that using Miracle Gro Moisture Control Potting Soil, the blue and green bag and NOT the "organic" material in the white bags from landfills, has worked quite well. With the reinforced screen bottoms, drainage is superb, even during extreme rains. The soil type retains good moisture levels even when the aridity is higher and the winds extreme. If you desire, you can lighten the seed cover by adding perlite or even using a seed starter mix to cover the seeds, but the moisture control soil is perfect in the SoCal climates.

Please feel free to browse the blog if you desire and ask any questions you may have. I do wonder, however, if the issue you feel you are experiencing may simply be possibly not waiting long enough for germination of seeds which may be a bit longer delayed due to the lower stratification temperatures and the seeds not receiving the proper stimulation from the weather by not remaining outdoors for the greater extremes between day and night? Good luck!
Kim
California Central Coast
USDA Zone 9b
Sunset Zone 15
Cooler inland coastal valley with strong marine influence

henry kuska
Posts: 1118
Joined: Thu Dec 15, 2011 9:06 pm

Re: Seed failure.

Post: # 73493Post henry kuska
Sun Nov 14, 2021 8:28 pm

I placed my boxes right on the soil (zone 5 northern Ohio). I used metal screens to prevent the "critters" from gnawing through plastic type screens.

Plazbo
Posts: 211
Joined: Tue May 09, 2017 12:18 am

Re: Seed failure.

Post: # 73495Post Plazbo
Mon Nov 15, 2021 2:44 am

I'm on the other side of the pacific (Sydney, Australia) but similar monthly avg temps, just have rain year round.

I sow outdoors beginning of March (first season of Autumn/Fall and sow what ripens later as it's ready) without stratification, around mid to late March is around the time min temps start to fall below 15c/60f somewhat consistently, seems roughly required to get germination, don't seem to get much if any germination when min temps are above that here.

Similar to Kim in using long, wide planters, outside of pulling out duds to bin or exceptionally vigorous seedlings to pot individually most seedlings will be in the box a long time as I'm not doing much outside during the day from mid spring onwards, the sun is just too harsh for how pale I am.

As for what you've done wrong, possibly nothing. May just need more time, may have been dud seed (eg Sunny Knock Out and Golden Wings make a lot of seed but not a lot of germinations). May be helpful to post who the seed parent/s are to seem if they are a difficult parent.

roseman777
Posts: 1
Joined: Sun Nov 14, 2021 5:34 pm

Re: Seed failure.

Post: # 73514Post roseman777
Sun Nov 21, 2021 4:05 pm

Had to change my username because having trouble with account activation.

Thanks you all so much for the comments and advice. Much appreciated!

I’ve been hybridizing a wide mix including high and yellow flame, ebb tide, Don Juan, golden opportunity, graham thomas, beloved, and wildfire. A mix of hydrid teas, climbers, floribundas, and even an old English rose. I’ll look to give your techniques a try.

One question I still have is what does it mean when all I see is a root breaking the surface?

Also, I’ve read that I should keep the seedlings at 70 Degress but your advice was to expose then to extremes. Curious as to the reason for this conflict.

roseseek
Posts: 5297
Joined: Sun Dec 11, 2011 6:54 pm
Location: Zone 9b Central California, Sunset Zone 15

Re: Seed failure.

Post: # 73515Post roseseek
Sun Nov 21, 2021 4:22 pm

I had routinely read that germination occurs at temperatures below 70F. From observation, germination can continue well into the mid to high eighties as long as evening remain cool (fifties to sixties). "Extremes" meaning nights of high forties and above and days into the seventies or so. That range usually indicates the season is moving from "winter" into "spring" when they safely germinate. If the temps are too low, they "know" is is unsafe to germinate due to potential for freezes. If the temps are too high, they usually stop because they "know" the chances of survival are too low due to being cooked, fried by too high heat or extreme sun. You want a range of temperatures between the very cool nights and warm but not blistering days as the seeds pop out of the ground quite well at those temperatures. As for "root breaking the surface", I"m sorry but I have no idea what you mean by that. It is something I have never observed. Roots tend to grow with gravity. Stems grow against gravity, toward light. Roots grow away from light.
Kim
California Central Coast
USDA Zone 9b
Sunset Zone 15
Cooler inland coastal valley with strong marine influence

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