Hello! I’m new here, long time reader, first time poster. I got into the world of roses over the last few years and decided to try my hand at stratifying and growing some OP achenes before dabbling in hybridising over the coming spring/summer 2024.
The rose is a small David Austin looking climber of unknown variety outside my house that has been here for many years, planted before I moved in. It sets hips every year so I thought it would be a good idea to try and grow some of them.
I opened the fridge today after 3 months of cold to find my first seed had germinated! it’s been potted up ready to grow under lights. I’ve attached a photo.
Welcome Alex! After three years I still consider myself a beginner, but I’ve learned enough lessons the hard way, that I’m beginning to feel I can lend a bit of advice.
I didn’t provide enough artificial light the first year, and the seedlings were quite spindly. Get good quality LED grow lights, and measure/regulate the amount you give them everyday. You can use the Photone app to measure the light quantity, and I have found a Daily Light Integral (DLI) of 15-18 to be about the minimum to keep seedlings thriving. Take some time, and read up on it, and you’ll be ahead of the game. Expect to learn a lot about cannabis culture while you’re at it
Welcome Alex!! Congratulations on your first germination and good luck to you!
I would second what Lee said about light. I would also suggest that you make sure that the soil you use is very light. I add very fine perlite (I sifted medium perlite through a fine sieve) to seed starting mix. I use about a 50:50 ratio. This will prevent damping off and root rot. Then only water when the soil has dried out at the surface.
Watch out for two-spotted spider mites which are pretty much inevitable regardless of the source of your soil (unless it has been steam-sterilized). These start imperceptibly but multiply exponentially and will destroy your seedlings given the long winter ahead. Pesticides are ineffective against the eggs. The only way to prevent them is to steam-sterilize your moistened potting soil which you can do by ‘roasting’ it in the oven at ~220 degrees for at least one hour. I measure the temp with a meat thermometer to make sure it reaches the boiling point.
Since you already have pots started you should remove the seedlings and rinse them off thoroughly, starting over with clean pots and sterilized soil. It may seem like heroics but is worth the effort now rather than trying to extinguish them later.
Using fluorescent or led lamps keep your lights as close to the plants as possible, recalling the inverse-squared relationship of light intensity to distance. It is impossible to give them too much artificial light. Keep the lights on 24/7, roses are not photoperiodic. Surround your plants with white reflective surfaces, even if it’s just paper taped to the light fixtures. This evens out the light distribution and multiplies the intensity.
Get your seedlings into direct sunlight as soon as practical although introduce it gradually as your seedlings are put outdoors. Be aware of the need to ‘harden’ them to direct sunlight. I start by putting them under a glass table top so that the mid-day sun reaches them whilst the damaging UV gets filtered out. Start as soon as daytime gets in the 40’s taking them inside at night until last frost.
Thank you for your comments on spider-mites Don. I hadn’t given thought to their presence in potting soil which probably explains the current infestation in my overwintering rooted cuttings. Will start baking and re-potting in January.
Seasons Greeting to everyone.
May 2024 be healthy and happy!
I too am relatively new to rose crossing and selection but I have stayed with the natural route with germination totally outdoors (Southern England) with the first seedling emergence this year on 21st December after sowing 9 October. The seedlings will stay outside in the weather, pricked out into individual modules from February onwards, though I expect most seeds to germinate from February onwards and be pricked out into modules as soon as seed leaves fully expand. Following on from other comments, I use a lot of perlite mixed with the compost. Going the indoor route, I expect spider mites would always be likely to come up as a problem and it is not just a matter of hygiene, but spider mites are always potential invaders and thrive in a clean protected indoor environment unless you are going to introduce appropriate spider mite predators. However, I must confess my seed germination rates are still low for most crosses, so I still keenly read all postings related to getting better germination
