Hello everyone,I am Chio. I would like to ask a question about how to sow seeds to increase the germination rate. In the past few years, my seed germination rate has not been high, so I began to doubt whether there was a problem with my own method. Therefore, I would like to ask everyone what medium is used, when is the sowing time node, and what is the sowing method?
Welcome, Chio! The most appropriate answers to your questions will depend upon the weather and conditions where you are. We have members in very cold, short season, northern climates who sow their seeds under refrigeration and remove the sprouted ones to grow under lights. I live along the Pacific Ocean in Central California where I can pollinate most of the year and plant the seeds outdoors any time other than during the heat extremes, which are generally late August to early to mid October. Here, the rainfall total is usually about 15" a year and mostly from December to March. The rest of the year is rather arid with fairly consistent wind. Maintaining soil moisture for me is best accomplished by using a moisture control potting soil containing Coir to help hold more moisture between waterings. For those with significantly greater rainfall, the moisture control soil can literally lead to rotted plants as it tends to retain too much moisture in wet climates. What’s appropriate for me here, isn’t appropriate for someone where the rain is much heavier and more regular and where winter is far more severe. You may receive much more helpful responses if you provide more information about what climate conditions you are gardening in. Thank you!
Hi Roseseek,thank you very much for your reply
I live in Jiangsu Province, China, with a subtropical monsoon climate. The spring climate here is very pleasant, with an average temperature of around 12-20 degrees Celsius. In summer, it is very hot and dry, lasting for three to four months with high temperatures, and the highest temperature may even reach 40 degrees Celsius. At the same time, there is frequent rainfall in summer, often with several days of rain. Autumn is very cool and humid. As soon as autumn enters, the temperature will instantly drop to a cool and comfortable temperature. The temperature difference between day and night in autumn is relatively large, and the night will be a bit cold. Around December of each year, most roses begin to enter a dormant state, which lasts for more than three months until they sprout and bloom again in the spring of the following year.
In the past few years, I have picked rose fruits in autumn, peeled the seeds, mixed them in a mixture of moist perlite and peat soil, frozen them in the refrigerator for about 40 days, and then seeded them. Some will germinate in the autumn of that year, while others will germinate in the spring of the following year, but the germination rate is not very high. One more point: The medium I use for sowing is the local garden soil mixed with vermiculite.
My first recommendation would be to lengthen the period in the refrigerator; it usually take several months for my seeds to lose their dormancy and become ready to germinate, not several weeks.
Another thing that might be worth a try is using something more enriched with microorganisms than peat alone. I use a mixture of peat and manure/compost, which likely contains beneficial organisms that are antagonistic toward microorganisms that harm seeds and germinating seedlings, and also help to break down the germination inhibitors and physical barriers to germination. In other words, using a medium that is too sterile might be a disadvantage.
You’re welcome, Chio. Your climate sounds (other than the sub tropical monsoon) like my old Los Angeles climate as far as the temperatures are concerned. Are you working with species roses or modern? Even for species crosses (R Primula, Xanthina, Hugonis, Stellata mirifica, Fedtschenkoana, Minutifolia, Arkansana) no cold stratification is required. I harvest and plant out doors as soon as is convenient with a sufficiently high rate of germination to provide me with more seedlings than I can comfortably handle. The only unknown for me in the situation are you rains. I would think you might benefit from the use of Perlite in your garden soil rather than vermiculite. If your soil is sandy, vermiculite may be better but if your soil is heavier, then you want perlite to provide drainage. I wonder if the issue may be freezing them for forty days? Freezing delays germination, which is beneficial if you’re attempting to avoid periods of extreme cold (or even extreme heat). Have you tried planting without the freezing period?
Thank you for your suggestion.
This year, I plan to try planting some seeds directly without refrigeration. Our soil is not breathable, so perhaps mixing some coarse particles for drainage would be better
I have never tried sowing seeds directly without refrigeration, because when I watch other people’s videos, I first refrigerate the seeds, so I also follow their methods. I always thought this was a necessary step. Most of the roses I hybridize with are modern roses, while a small portion use native roses from China, such as sparse rose, moon powder, etc
Hi MidAtlas,Thank you very much for your reply. May I ask what is the approximate ratio of peat and manure you use
You’re welcome. Vermiculite is used to retain water and it breaks down into clay, aluminum silicate. Perlite sounds as if it’s what you need. I refrigerated my seeds for MANY years, until I decided one year I didn’t want to deal with it, so I left them in the house, off refrigeration and then planted when the temperatures were appropriate (when the temps above 26.7 C were finished for the year. I had read for years that rose seeds stop germinating at around 70 F (21 C), however I kept observing them continuing to germinate up to a bit over 26.7 C, so why not plant then? It sounds as if the issue to be most concerned about after the very high temps would be to protect the planted seeds from the monsoon rains. Otherwise, it sounds as if you’re on your way! Good luck! Fingers are crossed for you!
Generally I would say that it is something like 60% peat to 40% composted manure-compost blend. The precise ratio isn’t overly critical, and depends a bit on the properties of the compost-manure blend that I purchase, which varies from batch to batch. Sometimes it smells less fully composted (having a stronger fresh manure smell), in which case I’ll use a little less; other times it smells more like fresh soil with very little manure smell, and then I’ll use a bit more. I don’t add vermiculite or Perlite to the stratification mix. I just make sure that it has just the right amount of moisture. For what it’s worth, I don’t use vermiculite or Perlite in potting mixes, either. I use a similar blend for growth, which has some of the same benefits for the seedlings and plants.