Pests and diseases: Prevention is the best way to avoid pest and disease problems. Start with disease-resistant varieties, keep plants in healthy condition (well fertilized and well watered), maintain good air circulation, keep foliage dry, and remove any diseased foliage or spent flowers. For Japanese beetle grubs, use beneficial nematodes or Milky Spore (Bacillus popilliae). Rose Rx is effective against scale, spidermites and aphids. For more information, see the Pest and Disease Finder.
Rose seeds need to go through stratification (an artificial cold spell) for 10 to 12 weeks before they will sprout. This, combined with a germination success rate of 20-30% makes propagation by seed an unattractive prospect. on by seed an unattractive prospect. If you still want to try it, find a good source of information that will guide you through the process.
Remove the seeds from the fridge. Try to do this around the time that the seeds would normally start to germinate, such as in early spring. Make sure that the environment outside of the fridge is about 70 degrees Fahrenheit. The seed will not sprout until you take them out of the fridge. Depending on the rose variety and individual seeds, the seeds could take anywhere from four to sixteen weeks to germinate. Often, 70% or more of the seeds never sprout at all.
Water. Irrigate roses deeply but infrequently, applying water directly to soil using soaker hoses or drip irrigation. Water needs vary based on weather and soil, so check soil with your finger. Water often enough to create consistently moist soil – not overly wet, not bone-dry. To prevent diseases, keep foliage dry, especially if you must water late in the day.
Be aware of your variety’s needs. Rose care will depend a lot on the variety you’re raising. Some roses like William Baffin and Lady Hillingdon climbing roses are more drought tolerant, for example, while others need more water. Some varieties can withstand less sunlight than others. Rose varieties should also be pruned differently depending on the variety and your climate area.
Water the planted rose seeds well and place them outside in direct sunlight (no need for Grow Lights). If there is still danger of frost, then you will need to place the seed trays in a protected location such as under a tree or patio. You will need to keep the rose seed trays watered and don't let them dry out. After about six weeks, or when the weather starts to warm up, the little rose seedlings will start to sprout. They will continue to sprout as long as the weather is cool, but will stop sprouting when it gets too hot.
Growing roses from seed is certainly not the fastest method of propagating roses, but I can assure you it really is the most rewarding. However, rose hybridizing is surely a lesson in patience, since your success rate can be very small, and it may take several years to reap your rewards. Imagine opening up presents on your birthday or at Christmastime when you were a kid. Well, that's how it feels to see those little rose seedlings open up for the very first time. You never know what you will find inside.
Hi Katherine, You may have hit the reason. One of the most common reasons for roses not blooming well is the use of high nitrogen fertilizers or the over use of them. This will result in few to no blooms or small blooms and lots of foliage. Use a well balanced food or fertilizer when feeding your roses so that all of the rose’s nutritional needs are met.