How to Grow Rose Seeds? Detailed Planting Guide
Roses are usually propagated by cuttings, and growing them from seed is very rare. First, because the seed germination rate is low; second, because seed propagation causes degeneration; and third, because seeds are not easy to obtain. But no matter how difficult it is, that does not mean it is impossible. Propagating roses from seed is suitable for breeding new rose varieties. Let's take a look at how to grow rose seeds.
What characteristics do rose seeds have?
Rose seeds have a dormant characteristic. Generally, there are three reasons for plant seed dormancy:
1. The seed coat is hard, which restricts water absorption and respiratory metabolism.
2. The embryo is not fully developed and must undergo after-ripening before it can germinate.
3. The presence of certain inhibitors inhibits seed germination.
The reason for rose seed dormancy is caused by the ABA (abscisic acid) contained in the pericarp and seed coat. This is the result of high performance liquid chromatography (HPLC) determination. The pericarp, seed coat and embryo of rose seeds all contain ABA. Through tissue culture methods, it has been confirmed that the relatively high level of ABA contained in the pericarp and seed coat is the main cause of seed dormancy. The amount of ABA contained in the embryo is extremely small and not enough to cause seed dormancy.
Pre-sowing treatment of rose seeds
Due to the above characteristics of rose seeds, newly harvested seeds cannot germinate. Before sowing, they must undergo "sand stratification" treatment before they can germinate and emerge. That is, mix the seeds into moist sand, place them in a container, cover with 3-5 cm of moist sand, and place under 0-2°C conditions, refrigerate for 60-90 days, and then sow.
Sowing methods for rose seeds
Sowing should be carried out under 5-10°C conditions. It can be done by dibbling, broadcasting, drilling or pot sowing, with a spacing of 3 cm. After sowing, cover with a 1 cm layer of vermiculite or plain sand. Under normal circumstances, seedlings can emerge about 40 days after sowing.
Precautions for propagating roses from seed
1. Generally around November, cut off the mature fruits whose pericarp color has turned yellow and red, and store them in moist sandy soil at 0-6 degrees. In January and February of the following year, select seeds and prepare them for germination. Put the pre-selected plump seeds into a plastic bag containing moist sandy soil, fine wood shavings or vermiculite, tie the bag tightly, and place it in a dark environment with freezing nights and thawing days and drastic temperature changes. As the temperature rises, check once a week, and carefully pick out the seeds that have cracked and shown white.
2. Plant the seeds that have cracked after germination at a plant-to-row spacing of 3 cm * 5 cm carefully in the seedbed. The lower part of the seedbed can use river sand or garden soil, covered with a thin layer of vermiculite (or fine wood shavings). Place the germinated seeds on it, then carefully cover with a layer of sandy soil about 1 cm thick, and finally spray thoroughly with water using a watering can.
3. Note that the sowing soil must be disinfected and dewormed. The seedbed is best arranged inside a greenhouse, and at the same time cover the arched shed with plastic film, keep the seedbed moist frequently, and maintain a suitable temperature of about 20 degrees for germination and seedling growth. After the seeds emerge and grow 3 to 5 leaves, promptly move them to small flower pots to promote the growth of the seedlings. To promote rapid growth of the seedlings, the potting soil should be kept loose, and it is advisable to apply thin fertilizer frequently and provide more sunlight, but do not water too much, so as to avoid inducing diseases.