Prepare a pot. Fill the small pot with potting soil. For the best results, replace a quarter of the soil with perlite, peat moss, or vermiculite, or a combination thereof. This will increase air flow and draining, giving your cutting a better opportunity to root. If the soil is dry, water it and allow the excess water to drain out, so that the soil is evenly moist.
The plant will become dormant—and you want it to stay that way; it is the natural state. After the first deep freeze, put is in a room or place (garage) with no heat and natural light (window). You can add some water occasionally but this is not intended to be “watering”; the plant is dormant and will not take it up but the soil can be lightly moist. Bring the plant back outside when it shows signs of coming back to life. Plant it, per the guidance above, when the soil warms.
Fertilizer: Roses are heavy feeders, and will benefit from a steady supply of nitrogen, phosphorus and potassium. You can provide these nutrients with either liquid or granular fertilizers, at a ratio of approximately 5-8-5. In most cases, regular applications of compost, rotted manure, fish emulsion and seaweed extracts will provide roses with all the nutrients they need. These organic amendments also help to moderate pH imbalances and stimulate beneficial soil life. Other organic amendments favored by rose growers include greensand, black rock phosphate and alfalfa meal.
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.
When you grow roses from seed, you are essentially developing new varieties of roses. If the rose fruit -- called a hip -- was produced by bee pollination, you don't know what varieties were crossed to get the seeds. Rose breeders hybridize chosen varieties and select for particular traits in resultant seedlings. However, each seedling will be a surprise. Rose seeds have to be collected in the fall, cleaned, and cold-treated before they are planted. Even though the cleaned seeds may look dry, they are not dry inside. If rose seeds are allowed to sit around in the open air and dry up completely, they will not grow.
I received some seeds as birthday present, the seller included a bonus packet of rose seeds. There’s no indication if they’ve been stratified. If I stratify them now, it will be July when they’re ready to plant. In this region (I’m ~50 miles north of Portland, Oregon)it might be mild or very hot. I’ve read that rose seed won’t sprout if it’s too hot – how well do rose seeds keep? Will they still be viable next Spring, or should i take a chance on the weather and start them now?